Ventilators · 800 Series family

Puritan Bennett 840: troubleshooting and error codes

The ServiceForge knowledge base holds 222 documented symptoms for the Puritan Bennett 840, with 568 ranked causes, 314 diagnostic checks with test points and expected values, and 571 error codes. Each symptom below shows its causes and the first check; the rest is one connection away. Connect ServiceForge to your AI

Symptoms

Exhalation valve calibration fails

Calibration procedure does not complete successfully; error messages displayed during Exp Valve Calibration function execution.

Ranked causes

1. System leak, particularly expiratory filter leaks (common)
2. Exhalation valve and/or analog interface PCB out of specification (occasional)
3. Analog Interface PCB out of specification (occasional)
4. Gold standard circuit not connected or expiratory filter not locked (occasional)
5. Exhalation valve temperature out of range (rare)
6. Expiratory filter leaks (common)
7. Flow sensor calibration table checksum error (rare)
8. No air connected to ventilator (occasional)

First check

Verify ventilator warm-up time

Test point: Service mode
Expected: Ventilator has been in service mode for at least 10 minutes

3 more checks with pass and fail actions, 9 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Oxygen zero flow check failed caution

Q1 oxygen flow sensor reads > 0.05 L/min during zero-flow check when supplies disconnected

Ranked causes

1. Gas supplies not disconnected (common)
2. Compressor still running (common)
3. Q2 O-ring leakage (affects Q1) (occasional)
4. PSOL2 internal leak (affects O2 circuit) (occasional)
5. PSOL2 seating improper (occasional)
6. Q1 sensor calibration drift (occasional)
7. PSOL2 failure (rare)
8. Q2 sensor failure (rare)

First check

Read Q1 oxygen flow sensor during zero-flow condition

Test point: Q1 (oxygen flow sensor)
Expected: ≤0.05 L/min, ≤
Tools: EST system flow sensor reading

8 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Air flow cannot establish at 120 L/min patient safety

Flow controller unable to establish and control air flow at 120 L/min during EST

Ranked causes

1. Air supply disconnected, restricted, or low pressure (common)
2. Air PSOL defective (occasional)
3. System leak or occlusion (occasional)
4. Flow sensor calibration out of specification (occasional)
5. Q2 air flow sensor defective (rare)
6. Inspiratory Electronics PCB defective (rare)
7. AI PCB defective (rare)

First check

Verify air supply connected and unrestricted

Test point: air inlet
Expected: connected and clear

7 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Air zero flow check failed caution

Q2 air flow sensor reads > 0.05 L/min during zero-flow check when supplies disconnected

Ranked causes

1. Gas supplies not disconnected (common)
2. Compressor still running (common)
3. Q2 O-ring leakage (occasional)
5. PSOL2 seating improper (occasional)
6. Q2 sensor calibration drift (occasional)
7. PSOL2 internal fault (rare)
8. Q2 sensor failure (rare)

First check

Read Q2 air flow sensor during zero-flow condition

Test point: Q2 (air flow sensor)
Expected: ≤0.05 L/min, ≤
Tools: EST system flow sensor reading

8 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration: Flow Sensor

Automatic calibration of air, oxygen, and exhalation flow sensors with atmospheric pressure transducer zeroing using external barometer reference

Ranked causes

1. Air offset out of range during calibration (unknown)
2. O2 offset out of range during calibration (unknown)
3. Cannot achieve minimum air flow (60 L/min) (unknown)
4. Cannot achieve minimum O2 flow (60 L/min) (unknown)
5. No air connected (unknown)
6. No O2 connected (unknown)
7. AC power not connected (unknown)

First check

Enter Service Mode

Test point: Service Mode menu
Expected: Service Mode accessible

7 more checks with pass and fail actions, 11 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Oxygen flow cannot establish at 120 L/min patient safety

Flow controller unable to establish and control oxygen flow at 120 L/min during EST

Ranked causes

1. Oxygen supply disconnected, restricted, or low pressure (common)
2. Oxygen PSOL defective (occasional)
3. System leak or occlusion (occasional)
4. Flow sensor calibration out of specification (occasional)
5. Q1 oxygen flow sensor defective (rare)
6. Inspiratory Electronics PCB defective (rare)
7. AI PCB defective (rare)

First check

Verify oxygen supply connected and unrestricted

Test point: oxygen inlet
Expected: connected and clear

2 more checks with pass and fail actions, 7 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Air PSOL command current out of range patient safety

PSOL2 command current exceeds acceptable range during air flow verification at 120, 60, 5, or 1 L/min

Ranked causes

1. Air supply disconnected or restricted (common)
2. Air supply quality poor (occasional)
3. System leaks or occlusions (occasional)
4. PSOL2 defective (occasional)
5. Flow sensor calibration needed (occasional)
6. Q1 or Q2 flow sensor defective (rare)

First check

Verify air supply connected and unrestricted

Test point: air inlet
Expected: connected and clear

6 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Battery not charging after AC power reconnection high voltage

BPS not charging after AC power was reconnected during EST Battery Test.

Ranked causes

1. AC power not properly reconnected or AC supply is bad (common)
2. Faulty BPS PCB (occasional)
3. Defective battery pack (occasional)
4. Faulty power supply (occasional)
5. Defective BD CPU (rare)
6. Faulty AI PCB (rare)

6 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

O2 flow sensor cross check failed patient safety

Q1 and Q3 readings are too far apart during oxygen flow verification at 120, 60, 5, and 1 L/min

Ranked causes

1. Oxygen supply disconnected or restricted (common)
2. Oxygen supply quality poor (occasional)
3. System leaks or occlusions (occasional)
4. PSOL1 defective (occasional)
5. Flow sensor calibration out of specification (occasional)
6. Q1 oxygen flow sensor defective (occasional)

First check

Verify oxygen supply connected and unrestricted

Test point: oxygen inlet
Expected: connected and clear

3 more checks with pass and fail actions, 6 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

O2 PSOL command current out of range patient safety

PSOL1 command current exceeds acceptable range during oxygen flow verification at 120, 60, 5, and 1 L/min

Ranked causes

1. Oxygen supply disconnected or restricted (common)
2. Oxygen supply quality poor (occasional)
3. System leaks or occlusions (occasional)
4. PSOL1 defective (occasional)
5. Flow sensor calibration needed (occasional)
6. Q1 or Q2 flow sensor defective (rare)

First check

Verify oxygen supply connected and unrestricted

Test point: oxygen inlet
Expected: connected and clear

6 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Oxygen flow sensor cross-check failed patient safety

SST Flow Sensor Test failure: Q1 and Q3 readings are too far apart at oxygen flows of 120, 60, 5, and 1 L/min

Ranked causes

1. System leak (common)
2. Safety valve open (occasional)
3. Flow sensor calibration drift (occasional)
4. Q1 oxygen flow sensor malfunction (occasional)
5. Q3 exhalation flow sensor malfunction (occasional)
6. AI PCB malfunction (rare)

6 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Air PSOL excessive pressure buildup 50-100 cmH2O caution

Air PSOL forward leak detected via excessive pressure in blocked inspiratory module, pressure between 50 and 100 cmH2O

Ranked causes

1. Leaking Q2 O-rings (common)
2. Air supply disconnected or restricted (occasional)
3. PSOL2 seating issue (occasional)
4. Air PSOL internal leak (occasional)
5. AI PCB fault (rare)

First check

Measure inspiratory pressure with safety valve open and then closed

Test point: Inspiratory pressure sensor
Expected: 50-100 cmH2O (indicating forward leak)
Tools: Pressure transducer

5 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Air PSOL forward leak detected patient safety

Excessive pressure buildup (> 50 cmH2O but < 100 cmH2O) detected in blocked inspiratory module with air PSOL enabled

Ranked causes

1. Q2 O-ring leaking (common)
2. Air supply not connected or restricted (common)
3. Air PSOL2 not fully seated (occasional)
4. Air PSOL2 defective (occasional)
5. AI PCB defective (rare)

First check

Check Q2 O-rings for leaks

Test point: Q2 O-ring seals
Expected: dry, no visible leakage

5 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Backup power supply voltage out of range

BPS voltage dropped below accepted level or dropped too quickly during discharge test

Ranked causes

1. Battery pack not fully charged before EST (common)
2. Battery pack defective (occasional)
3. BPS PCB control circuit failure (occasional)
4. Power supply unit failure (occasional)
5. AI PCB failure (rare)

First check

Check BPS LED charge status before EST

Test point: BPS LED indicator
Expected: Green LED lit (fully charged)

5 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Battery backup not charging

BPS (Battery Power Supply) not charging after AC power reconnected

Ranked causes

1. AC power not properly reconnected (common)
2. BPS PCB charging circuit failure (occasional)
3. Battery pack defective (occasional)
4. Power supply unit failure (occasional)
5. BD CPU or AI PCB failure (rare)

First check

Verify AC power supply and connection

Test point: AC power cord, outlet
Expected: AC power good and connected

5 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Battery voltage drops during backup power test high voltage

During EST Battery Test, backup power supply (BPS) voltage dropped below accepted level or too quickly while discharging.

Ranked causes

1. Battery pack not fully charged (common)
2. Defective battery pack (occasional)
3. Faulty BPS PCB (occasional)
4. Faulty AI PCB (occasional)
5. Defective power supply (rare)

5 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Exhalation zero flow check failed caution

Q3 exhalation flow sensor reads > 0.1 L/min during zero-flow check when supplies disconnected

Ranked causes

1. Gas supplies not disconnected (common)
2. Compressor still running (common)
3. Q3 O-ring leakage (occasional)
4. Q3 sensor calibration drift (occasional)
5. Q3 sensor failure (rare)

First check

Read Q3 exhalation flow sensor during zero-flow condition

Test point: Q3 (exhalation flow sensor)
Expected: ≤0.1 L/min, ≤
Tools: EST system flow sensor reading

5 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Inspiratory and expiratory pressure cross-check failed at 10 cmH2O patient safety

Inspiratory and expiratory pressure transducer readings diverge beyond acceptable tolerance at 10 cmH2O test pressure.

Ranked causes

1. Patient circuit leak or occlusion (common)
2. Ventilator system leak or occlusion (common)
3. Inspiratory pressure transducer out of range (occasional)
4. Expiratory pressure transducer out of range (occasional)
5. AI PCB electronics failure (rare)

First check

Verify patient circuit has no leaks or occlusions

Test point: Patient circuit system
Expected: No leaks or occlusions

2 more checks with pass and fail actions, 5 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Inspiratory and expiratory pressure cross-check failed at 50 and 100 cmH2O patient safety

Inspiratory and expiratory pressure transducer readings diverge beyond acceptable tolerance at high pressure levels (50 and 100 cmH2O).

Ranked causes

1. Expiratory bacteria filter clogged or restricted (common)
2. System leak or occlusion (common)
3. Inspiratory pressure transducer out of range (occasional)
4. Expiratory pressure transducer out of range (occasional)
5. AI PCB electronics failure (rare)

First check

Inspect expiratory bacteria filter

Test point: Expiratory filter
Expected: Filter clean and unobstructed

2 more checks with pass and fail actions, 5 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

O2 zero flow check failed patient safety

Oxygen flow exceeds 0.153 L/min when PSOL1 is commanded to deliver 0 L/min (closed)

Ranked causes

1. Q1 O-ring leaking (common)
2. PSOL1 leaking (common)
3. PSOL1 defective (occasional)
4. Flow sensor calibration out of specification (occasional)
5. Q1 oxygen flow sensor defective (rare)

First check

Verify no leaks at Q1 O-rings

Test point: Q1 O-ring seals
Expected: dry, no visible leakage

1 more check with pass and fail actions, 5 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Oxygen flow sensor cross-check failure patient safety

O2 flow sensor readings (Q1) and exhalation sensor readings (Q3) diverge beyond acceptable tolerance during oxygen flow test.

Ranked causes

1. System leak or occlusion (common)
2. Safety valve stuck open (occasional)
3. Q1 sensor malfunction (occasional)
4. Q3 sensor malfunction (occasional)
5. AI PCB electronics failure (rare)

First check

Check for system leak

Test point: System circuit
Expected: No leaks detected

2 more checks with pass and fail actions, 5 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Oxygen PSOL current out of range patient safety

Oxygen proportional solenoid (PSOL1) command current is outside acceptable range during diagnostic test.

Ranked causes

1. System leak or occlusion (common)
2. Safety valve stuck open (occasional)
3. Oxygen regulator pressure out of specification (occasional)
4. PSOL1 solenoid valve malfunction (occasional)
5. AI PCB electronics failure (rare)

First check

Check for system leak

Test point: System circuit
Expected: No leaks detected

2 more checks with pass and fail actions, 5 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Oxygen PSOL excessive pressure buildup 50-100 cmH2O caution

Oxygen PSOL forward leak detected via excessive pressure in blocked inspiratory module, pressure between 50 and 100 cmH2O

Ranked causes

1. Leaking Q1 O-rings (common)
2. Oxygen supply disconnected or restricted (occasional)
3. PSOL1 seating issue (occasional)
4. Oxygen PSOL internal leak (occasional)
5. AI PCB fault (rare)

5 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

SST flow sensor test fails - unable to establish oxygen flow patient safety

Flow controller unable to establish and control oxygen flow at 120 L/min during SST test

Ranked causes

1. Oxygen supply not connected or unrestricted (common)
2. Patient circuit system has leaks or occlusions (common)
3. PSOL (proportional solenoid) malfunction (occasional)
4. Q1 or Q2 flow control valve malfunction (occasional)
5. Flow sensor calibration error (occasional)

First check

Verify oxygen supply connection and pressure

Test point: PS1 pressure switch, oxygen regulator output
Expected: 9-12 psi at regulator; PS1 detects pressure

4 more checks with pass and fail actions, 5 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Test circuit not connected caution

Pressure not detected on expiratory side during leak test; inspiratory/expiratory pressure transducer readings too far apart

Ranked causes

1. Test circuit not properly connected (common)
2. Expiratory bacteria filter blocked or defective (occasional)
3. Q3 flow sensor O-ring leakage (occasional)
4. Exhalation valve malfunction (occasional)
5. Expiratory pressure transducer PCB failure (rare)

First check

Compare inspiratory vs expiratory pressure readings during pressure hold

Test point: Inspiratory pressure sensor vs expiratory pressure sensor
Expected: Pressures closely match
Tools: Pressure transducers, EST system

5 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Test circuit not connected (pressure transducer readings far apart)

Pressure not detected on expiratory side; inspiratory/expiratory pressure transducer readings too far apart

Ranked causes

1. Test circuit not properly connected (common)
2. Expiratory bacteria filter clogged (occasional)
3. Leaks at Q3 flow sensor (occasional)
4. Exhalation valve malfunction (occasional)
5. Expiratory pressure transducer PCB failure (rare)

First check

Verify test circuit connection to expiratory side

Expected: Pressure detected on expiratory transducer

1 more check with pass and fail actions, 5 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Unable to establish air flow at 120 L/min patient safety

Flow controller cannot establish and control air flow at 120 L/min during diagnostic test.

Ranked causes

1. Air supply disconnected or restricted (common)
2. Patient circuit leaks or occlusions (common)
3. Air regulator pressure out of range (occasional)
4. PSOL2 solenoid malfunction (occasional)
5. Q2 air sensor malfunction (occasional)

First check

Verify air supply connection and restriction

Test point: Air inlet
Expected: Connected and unrestricted

4 more checks with pass and fail actions, 5 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Unable to establish air flow at 60, 5, and 1 L/min patient safety

Flow controller cannot establish and control air flow at lower rates (60, 5, 1 L/min) during diagnostic test.

Ranked causes

1. Air supply disconnected or restricted (common)
2. System leaks or occlusions (common)
3. Air regulator pressure out of specification (occasional)
4. PSOL2 solenoid malfunction (occasional)
5. Q3 exhalation sensor malfunction (occasional)

First check

Verify air supply connection

Test point: Air inlet
Expected: Connected and unrestricted

4 more checks with pass and fail actions, 5 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Unable to establish oxygen flow patient safety

Flow controller cannot establish and control oxygen flow at 60, 5, and 1 L/min during diagnostic test.

Ranked causes

1. Oxygen supply disconnected or restricted (common)
2. System leaks or occlusions (common)
3. PSOL1 solenoid valve malfunction (occasional)
4. Q1 oxygen sensor malfunction (occasional)
5. Q3 exhalation sensor malfunction (occasional)

First check

Verify oxygen supply connection and restriction

Test point: Oxygen inlet
Expected: Connected and unrestricted

6 more checks with pass and fail actions, 5 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Unable to establish oxygen flow at 120 L/min

Flow controller unable to establish and control oxygen flow at 120 L/min during SST flow sensor test.

Ranked causes

1. Oxygen supply disconnected, restricted, or low pressure (common)
2. Patient circuit system has leaks or occlusions (common)
3. Oxygen inlet filter assembly blocked (occasional)
4. Defective flow control solenoid Q1 (occasional)
5. Defective PSOL1 oxygen solenoid (occasional)

First check

Verify oxygen supply is connected and flow is good

Test point: oxygen inlet
Expected: oxygen supply connected and unrestricted

3 more checks with pass and fail actions, 5 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Unable to establish oxygen flow at 60, 5, and 1 L/min patient safety

SST Flow Sensor Test failure: flow controller cannot establish and control oxygen flow at 60, 5, and 1 L/min (lower flows)

Ranked causes

1. Oxygen supply restricted or disconnected (common)
2. System leak or occlusion (occasional)
3. PSOL1 malfunction (occasional)
4. Flow sensor Q1 malfunction (occasional)
5. Exhalation sensor Q3 malfunction (rare)

First check

Verify oxygen supply

Test point: Oxygen supply connection and regulated pressure
Expected: Connected and unrestricted; adequate supply

1 more check with pass and fail actions, 5 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Vent Inop Test fails

Service mode test procedure fails with 'Vent Inop Test failed' message on lower screen during BDU alarm, LED, or PSOL/valve inactivation checks

Ranked causes

1. BDU alarm failure (GUI vent inop test phase) (unknown)
2. Ventilator inoperative or safety valve open LED failure (unknown)
3. BDU alarm and LED failures combined (unknown)
4. PSOL/exhalation valve/safety valve inactivation failure (unknown)
5. Failure in Vent Inop A, B, or ten-second test phases (unknown)

First check

Verify BDU alarm operation in GUI vent inop test phase

Test point: BDU alarm
Expected: BDU alarm on (user prompt)

2 more checks with pass and fail actions, 5 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Air PSOL current out of range patient safety

Air proportional solenoid (PSOL2) command current is outside acceptable range during diagnostic test.

Ranked causes

1. Air supply disconnected or restricted (common)
3. Air supply pressure out of specification (occasional)
4. PSOL2 solenoid valve malfunction (occasional)
5. AI PCB electronics failure (rare)

First check

Verify air supply connection and restriction

Test point: Air inlet
Expected: Connected and unrestricted

2 more checks with pass and fail actions, 5 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Battery backup not discharging

BPS not discharging when loaded during test phase

Ranked causes

1. AC power not disconnected during test (common)
2. BPS PCB discharge circuit failure (occasional)
3. Battery pack defective or depleted (occasional)
4. BD CPU or AI PCB failure (rare)

First check

Verify AC power is disconnected

Test point: AC power cord
Expected: AC power disconnected

4 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Battery not fully charged

BPS not fully charged before EST begins

Ranked causes

1. Charging not allowed to complete (common)
2. BPS PCB charging circuit defective (occasional)
3. Battery pack defective (occasional)
4. BD CPU failure (rare)

First check

Verify AC power connected and BPS charging

Test point: AC power cord, BPS LED
Expected: AC connected, BPS LED indicates charging

4 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

BD alarm cable voltage out of range

Alarm cable voltage is < 3.5 V or > 5.05 V

Ranked causes

1. BD alarm cable not connected (common)
2. BD alarm malfunction (occasional)
3. AI PCB malfunction (occasional)
4. BD alarm cable damaged (occasional)

First check

Measure alarm cable voltage

Expected: 3.5 to 5.05 V, 3.5-5.05 V
Tools: DMM

4 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Calibration: Initialize Flow Sensor

Automatic copying of flow sensor calibration data from each sensor's serial EEPROM to BDU NOVRAM when data mismatch detected

Ranked causes

1. Unable to read air flow sensor serial EEPROM (unknown)
2. Unable to read O2 flow sensor serial EEPROM (unknown)
3. Unable to read exhalation flow sensor serial EEPROM (unknown)
4. Unable to program BDU NOVRAM (unknown)

4 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Compliance low (below 1.56 adult / 1.34 pediatric, second occurrence)

Low compliance falls below 1.56 mL/cmH2O (adult) or 1.34 mL/cmH2O (pediatric) but not below 1.05 mL/cmH2O during SST Compliance calibration test.

Ranked causes

1. Wrong patient tubing type specified in SST (common)
2. Defective patient circuit or filter (occasional)
3. Defective pressure transducer (PI or PE) (occasional)
4. Atmospheric pressure transducer out of calibration (occasional)

4 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Compliance low (below 1.56 adult / 1.34 pediatric)

Compliance falls below 1.56 mL/cmH2O (adult) or 1.34 mL/cmH2O (pediatric) but not lower than 1.05 mL/cmH2O during SST Compliance calibration test.

Ranked causes

1. Wrong patient tubing type specified in SST (common)
2. Defective patient circuit or filter (occasional)
3. Defective pressure transducer (PI or PE) (occasional)
4. Atmospheric pressure transducer out of calibration (occasional)

4 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Excessive compliance (>6 mL/cmH2O adult / 4.5 pediatric but <12/9)

Low compliance >6 mL/cmH2O (adult) or 4.5 mL/cmH2O (pediatric) but <12 mL/cmH2O (adult) or 9 mL/cmH2O (pediatric) during SST Compliance calibration test.

Ranked causes

1. Wrong patient tubing type specified in SST (common)
2. Defective patient circuit or filter (occasional)
3. Defective pressure transducer (PI or PE) (occasional)
4. Atmospheric pressure transducer out of calibration (occasional)

4 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Excessive system leak detected patient safety

System pressure drops excessively during leak test, indicating significant leak or occlusion in the patient circuit or system.

Ranked causes

1. Patient circuit not connected (common)
2. Patient circuit leak (common)
3. Exhalation valve malfunction (occasional)
4. Expiratory filter connection loose (occasional)

First check

Verify test circuit is connected

Test point: Test circuit connector
Expected: Circuit properly connected and seated

2 more checks with pass and fail actions, 4 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Excessive system leak during leak test caution

System pressure dropped below 85 cmH2O or pressure drops ≥5 cmH2O within 10 seconds after reaching 85 cmH2O

Ranked causes

1. Test circuit not connected or leaking (common)
2. System internal leaks (common)
3. Expiratory filter connection loose (occasional)
4. Exhalation valve malfunction (occasional)

First check

Wait for inspiratory pressure decay from 90 cmH2O or wait 10 seconds

Test point: Inspiratory pressure sensor
Expected: Pressure drops to 85 cmH2O or stable
Tools: Pressure transducer, EST system

4 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Exhalation valve seal leaking caution

Exhalation valve seal test shows pressure differential too high, indicating valve diaphragm not sealing properly

Ranked causes

1. Exhalation valve diaphragm contaminated (common)
2. Valve calibration incorrect (common)
3. Flow sensor Q3 miscalibrated (occasional)
4. Exhalation valve diaphragm damaged (occasional)

First check

Clean exhalation valve diaphragm

1 more check with pass and fail actions, 4 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Flow Sensor Calibration

Calibration of exhalation flow sensor (Q3) offset table using gold standard test circuit and dual gas sources (air and oxygen)

Ranked causes

1. Test circuit not attached or expiratory filter not secure (common)
2. System leak or expiratory filter leak (common)
3. Ventilator not at operating temperature (occasional)
4. Ventilator failed EST leak test (occasional)

First check

Verify ventilator has reached operating temperature

Test point: Ventilator thermal status
Expected: Operating temperature reached after 10 minutes warm-up in service mode

2 more checks with pass and fail actions, 4 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Flow sensor calibration fails

Flow Sensor Calibration procedure does not complete; error messages displayed during calibration execution.

Ranked causes

1. System leak, particularly expiratory filter leaks (common)
2. Test circuit not attached or not secure (occasional)
3. Ventilator has not reached operating temperature (occasional)
4. Flow sensor not passing EST leak test (occasional)

First check

Verify ventilator warm-up time

Test point: Service mode operation
Expected: Ventilator has operated in service mode for at least 10 minutes

4 more checks with pass and fail actions, 4 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Initialize Flow Sensor errors

Automatic flow sensor calibration data initialization fails with error messages during service mode startup

Ranked causes

1. Unable to read air flow sensor (Q2) EEPROM (unknown)
2. Unable to read oxygen flow sensor (Q1) EEPROM (unknown)
3. Unable to read exhalation flow sensor (Q3) EEPROM (unknown)
4. Unable to program BDU NOVRAM flash memory (unknown)

4 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Inspiratory and expiratory pressure transducer readings too far apart patient safety

Cross-check between inspiratory and expiratory pressure transducers at 50 and 100 cmH2O fails; readings diverge beyond acceptable tolerance

Ranked causes

1. Expired bacteria filter clogged or defective (common)
2. System leaks or occlusions (common)
3. Inspiratory or expiratory pressure transducer out of range (occasional)
4. AI PCB defective (occasional)

First check

Verify no system leaks or occlusions

Test point: circuit
Expected: no leaks or occlusions

1 more check with pass and fail actions, 4 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Inspiratory limb resistance low

Inspiratory limb pressure <0.6 cmH2O (adult) or 5.5 cmH2O (pediatric) but >0.2 cmH2O during SST Circuit Resistance test.

Ranked causes

1. Inspiratory filter not installed (common)
2. Test procedure not followed correctly (occasional)
3. Defective inspiratory filter (occasional)
4. Defective patient circuit (occasional)

4 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Oxygen PSOL forward leak detected (pressure 50-100 cmH2O) caution

Excessive pressure buildup (> 50 cmH2O but < 100 cmH2O) detected in blocked inspiratory module

Ranked causes

1. Oxygen PSOL forward leak (common)
2. Leaks around Q1 O-rings (occasional)
3. Restricted oxygen supply (occasional)
4. AI PCB malfunction (rare)

First check

Block inspiratory module and measure pressure

Expected: Pressure between 50-100 cmH2O indicates forward leak

4 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Power failure capacitor voltage out of range caution

Initial power failure capacitor voltage is < 4.5 V or > 5.05 V

Ranked causes

1. BD alarm cable not connected (common)
2. BD alarm malfunction (occasional)
3. AI PCB malfunction (occasional)
4. Motherboard PCB failure (rare)

First check

Measure capacitor voltage

Expected: 4.5 to 5.05 V, 4.5-5.05 V
Tools: DMM

2 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Pressure transducer cross-check failed at 10 cmH2O patient safety

SST Circuit Pressure Test failure: inspiratory and expiratory pressure transducer readings are too far apart at 10 cmH2O

Ranked causes

1. Patient circuit leak or occlusion (common)
2. System leak or occlusion (occasional)
3. Pressure transducer out of range (occasional)
4. AI PCB malfunction (rare)

4 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Pressure transducer cross-check failed at 50 or 100 cmH2O patient safety

SST Circuit Pressure Test failure: inspiratory and expiratory pressure transducer readings are too far apart at 50 or 100 cmH2O

Ranked causes

1. Expiratory bacteria filter clogged (common)
2. System leak or occlusion (occasional)
3. Pressure transducer out of range (occasional)
4. AI PCB malfunction (rare)

4 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Safety valve pressure relief failed patient safety

System unable to establish stable flow or safety valve cracking pressure is out of specification

Ranked causes

1. To patient port not blocked during test (common)
2. Leak at O2 sensor, SOL1, or PI (occasional)
3. Safety valve defective (occasional)
4. PI pressure transducer defective (occasional)

First check

Verify To patient port is blocked

Test point: To patient port
Expected: blocked

4 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Unable to establish leak test pressure caution

System cannot attain 90 cmH2O starting pressure during leak test within timeout period with either oxygen or air

Ranked causes

1. Test circuit not connected (common)
2. System leaks present (common)
3. Exhalation valve malfunction (occasional)
4. Expiratory filter connection loose (occasional)

First check

Pressurize system to 90 cmH2O using 2 L/min flow with oxygen or air

Test point: Inspiratory pressure sensor
Expected: ≥90 cmH2O, ≥
Tools: Pressure transducer, EST system

4 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Unable to establish test pressure

System cannot attain 90 cmH2O pressure with oxygen or air at 2 L/min flow within timeout

Ranked causes

1. Test circuit not connected (common)
2. System leaks present (common)
3. Exhalation valve not functioning (occasional)
4. Expiratory filter not securely connected (occasional)

First check

Verify test circuit connection

Expected: Test circuit properly connected to system

1 more check with pass and fail actions, 4 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Vent Inop Test failure during GUI vent inop test phase

GUI vent inop test phase fails during Vent Inop Test execution; BDU alarm, LED indicators, or PSOLs/exhalation valve/safety valve may not function correctly

Ranked causes

1. BDU alarm failure (occasional)
2. Ventilator inoperative or SVO LED failure (occasional)
3. BDU-GUI cable or CPU PCB communication failure (occasional)
4. BD CPU PCB or AI PCB failure (occasional)

First check

Observe BDU alarm during GUI vent inop test phase

Test point: BDU alarm output
Expected: Alarm activates on user prompt

2 more checks with pass and fail actions, 4 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

AC power not connected for EST patient safety

EST (Equipment System Test) cannot run on battery power; AC power required

Ranked causes

1. Ventilator not plugged into AC outlet (common)
2. Battery Power Supply (BPS) active (occasional)
3. Power supply defective (rare)

First check

Verify AC power connection

Test point: Ventilator power inlet
Expected: AC power cord connected to facility outlet

3 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Air flow cannot establish at 60, 5, and 1 L/min patient safety

Flow controller unable to establish and control air flow at lower rates during EST

Ranked causes

1. Air supply disconnected or low pressure (common)
2. PSOL2 or Q2 air flow sensor defective (occasional)
3. AI PCB defective (rare)

First check

Verify air supply connected

Test point: air inlet
Expected: connected

3 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

Air flow sensor cross-check failed patient safety

Air flow sensor (Q2) and exhalation sensor (Q3) readings diverge beyond acceptable tolerance during air flow test.

Ranked causes

2. Ventilator system leak or occlusion (common)
4. PSOL2 solenoid malfunction (occasional)
5. Q2 air sensor malfunction (occasional)

First check

Inspect patient circuit for leaks or occlusions

Test point: Patient circuit
Expected: No leaks or occlusions; no debris

3 more checks with pass and fail actions, 5 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

Air PSOL forward leak at high pressure patient safety

Excessive pressure buildup (> 100 cmH2O) detected in blocked inspiratory module with air PSOL enabled

Ranked causes

1. Q2 O-ring leaking (common)
2. Safety valve not opening at correct pressure (occasional)
3. Air PSOL2 defective (occasional)

First check

Verify safety valve cracks above 100 cmH2O

Test point: safety valve outlet
Expected: relief heard at pressure > 100 cmH2O on display

3 corrective actions and part numbers are in ServiceForge. Connect ServiceForge to your AI

More symptoms

Atmospheric Pressure Transducer calibration out of range
Battery pack system error
BD communication loss
Compressor load test failed
Compressor pressure not detected
Excessive circuit leak detected
Excessive leak in system (pressure drops >= 5 cmH2O in 10 seconds)
Excessive system leak
Exhalation valve temperature out of specification
Expiratory pressure transducer autozero out of range
Expiratory pressure transducer autozero solenoid SOL2 bad
Failed to reach test pressure
Failed to reach test pressure (10 cmH2O at 5 L/min)
GUI alarm sound not working
Inspiratory pressure transducer autozero out of range
Inspiratory pressure transducer autozero solenoid SOL1 bad
Inspiratory/expiratory pressure transducer cross-check failed
LCD controller PCB fault detected
Low circuit compliance
Low oxygen percentage (↓O2%)
O2 pressure detected with supply disconnected
Oxygen flow cannot establish at 60, 5, and 1 L/min
Oxygen pressure detected when disconnected
Power supply voltage error
Touch screen input failure
Touchscreen error occurred
Wall air pressure detected when disconnected
Wall air pressure detected with supply disconnected
AC power loss
Air PSOL excessive pressure buildup >100 cmH2O
Bad expiratory autozero solenoid
Bad inspiratory autozero solenoid
Cal Info Duplication errors
Calibration: Cal Info Duplication
Calibration: Power on self test (POST)
Calibration: Serial Number Setup
Circuit disconnect
Compressor leak detected
Compressor run time out of range
Excessive circuit compliance
Excessive compliance (high)
Expiratory autozero out of range
Failed to reach test pressure (50 or 100 cmH2O)
Failed to reach test pressure at 10 cmH2O
Failed to reach test pressure at 50 and 100 cmH2O
GUI 100% O2 LED fails
GUI 100% O2/CAL key fails
GUI Accept key fails
GUI Alarm Reset key fails
GUI Alarm Silence key fails
GUI Alarm Silence LED fails
GUI Alarm Volume key fails
GUI Battery Backup LED fails
GUI Clear key fails
GUI Compressor Operating LED fails
GUI Compressor Ready LED fails
GUI CPU not operational
GUI Expiratory Pause key fails
GUI High Alarm LED fails
GUI Info key fails
GUI Inspiratory Pause key fails
GUI keyboard key malfunction
GUI knob malfunction
GUI knob not responding
GUI LED indicator not illuminated
GUI Low Alarm LED fails
GUI Manual Inspiration key fails
GUI Medium Alarm LED fails
GUI Normal LED fails
GUI On Battery Power LED fails
GUI Screen brightness key fails
GUI Screen contrast key fails
GUI Screen lock key fails
GUI Screen Lock LED fails
High tidal volume (ΔVE TOT)
Low AC power
Low delivered tidal volume (ΔVE MAND)
Low expiratory filter pressure drop
Low inspiratory limb resistance
No air supply
Nurse call relay stuck off
Nurse call relay stuck on
O2 pressure not detected
Occluded exhalation compartment
Occluded expiratory compartment
Oxygen pressure not detected
Oxygen PSOL excessive pressure buildup >100 cmH2O
Oxygen PSOL forward leak detected (pressure > 100 cmH2O)
Wall air pressure not detected
Wall air pressure still detected after disconnect
Watchdog timer failure
AC power loss detected
Air pressure not detected via PS2 or PC
Air supply loss with O2 at 100%
Assertion boundary check failure in background diagnostics
Bad GUI serial port
Bus error or access fault
Calibration error during Flow Sensor Calibration
Calibration: Datakey Update
Calibration: Exhalation system
Calibration: Expiratory valve
Calibration: O2 sensor
Calibration: Oxygen sensor
Calibration: Performance verification
Calibration: Post-service verification
Calibration: Regulator calibration hose repair
Calibration: Remove or install 10.4-inch GUI
Calibration: Serial Loopback Test
Calibration: System Leak and Compliance Characterization (SST)
Cannot access service mode
Cannot program flash error
Compressor disabled mode time out of range
Compressor pressure detected during EST
Compressor pressure detected when depressurized
Compressor pressure detected when disabled
Compressor standby mode time out of range
Datakey not installed or not detected
Datakey update procedure
Electrical safety testing
Exhalation valve leak or EST failure
Expiratory limb resistance low
Gas not connected
GUI cable connection verification
High oxygen percentage (↑O2%)
Inspiratory autozero out of range
Loss of GUI LED fails
Low battery warning during AC loss
Low exhalation limb resistance
No O2 supply
No ventilation with safety valve open
O2 sensor out of calibration or failure
O2 supply loss with FiO2 at 21%
Occluded exhalation limb
Occluded expiratory filter
Occluded inspiratory limb
Oxygen pressure not detected via PS1
Performance verification testing required
Performance verification: calibration and testing
POST major fault detected; ventilator inoperative
POST minor fault detected during self-test
Procedure error during patient setup
Replace 10.4-inch GUI front housing
Replace 10.4-inch GUI keyboard assembly
Screen block or touch screen fault
Serial number does not match datakey
Service mode functions not executing
Severe occlusion in ventilator circuit
SST flow sensor test fails - air only available
SST flow sensor test fails - no gas available
SST flow sensor test fails - oxygen only available
SVO LED fails
System unable to establish pressure
Total loss of power
Troubleshooting ventilator diagnostic codes
Unable to establish stable expiratory filter flow
Unable to pressurize circuit during compliance calibration
Unable to reach minimum peak flow
Unable to reach minimum peak flow (alert threshold)
Unable to reach minimum peak flow (threshold 80-60 L/min)
Ventilator inoperative LED fails
Volume not delivered on VC+ or VS breaths
Wye not blocked during circuit resistance test

162 more symptoms with ranked causes and checks are in ServiceForge. Connect ServiceForge to your AI

Error codes

Code	Meaning	Trigger	Severity
`0B`	Alarm Cable Voltage test failure	POST analog device test failure	error
`0C`	O2 PSOL Current test failure	POST analog device test failure	error
`0D`	Air PSOL Current test failure	POST analog device test failure	error
`0E`	Low Voltage Reference test failure	POST analog device test failure	error
`0F`	Atmospheric Pressure Transducer test failure	POST analog device test failure	error
`10`	Exhalation Coil Temperature test failure	POST analog device test failure	error
`11`	Exhalation Pressure Transducer test failure	POST analog device test failure	error
`12`	O2 Sensor test failure	POST analog device test failure	error
`12 Vdc Overvoltage`	12V power supply overvoltage (GUI only)	Excessive 12V output	error
`12 Vdc Undervoltage`	12V power supply undervoltage (GUI only)	Insufficient 12V output	error
`13`	GUI 5V dc Sentry test failure	POST analog device test failure	error
`14`	12V dc Sentry test failure	POST analog device test failure	error
`15`	Safety Valve Current test failure	POST analog device test failure	error
`16`	+15V Sentry test failure	POST analog device test failure	error
`17`	-15V Sentry test failure	POST analog device test failure	error
`18`	Power Fail Cap Voltage test failure	POST analog device test failure	error
`19`	Exhalation Manifold Heater Temperature test failure	POST analog device test failure	error
`1A`	BPS Battery Voltage Signal test failure	POST analog device test failure	error
`1B`	5V dc Venthead test failure	POST analog device test failure	error
`1C`	BPS Battery Current test failure	POST analog device test failure	error
`1D`	ac Line Voltage test failure	POST analog device test failure	error
`1E`	Exhalation Motor Current test failure	POST analog device test failure	error
`1F`	10V Sentry test failure	POST analog device test failure	error
`5 Vdc Overvoltage`	5V power supply overvoltage (GUI only)	Excessive 5V output	error
`Access Fault/Bus Error`	Memory access fault or bus error	Invalid memory access during POST	error
`AC POWER LOSS`	Operating on battery; AC not available	Power switch on, AC unavailable, ventilator operating on BPS	warning
`AC POWER LOSS`	AC mains power unavailable	AC power disconnected or failed; ventilator switches to BPS battery power	error
`AC POWER LOSS`	AC input power is unavailable or insufficient; ventilator switched to battery power	AC monitor voltage falls below equivalent of 80 V AC at bulk supply input	warning
`ac power not connected`	AC power is not supplied to ventilator during exhalation valve calibration	Exhalation valve calibration procedure detects no AC power	critical
`AC power not connected`	Calibration cannot proceed; AC power is not connected to ventilator	Calibration attempted without AC power supply	error
`AE0110`	Unable to establish oxygen flow at 120 L/min	Flow controller unable to establish and control oxygen flow at 120 L/min	error
`AE0111`	Unable to establish air flow at 120 L/min	Flow controller unable to establish and control air flow at 120 L/min	error
`AE0213`	Air PSOL leak	EST Gas Supply/SV Test	warning
`AE0213`	Air PSOL leak: Excessive pressure buildup 50-100 cmH2O in blocked inspiratory module	EST disables compressor, bleeds pressure, reads inspiratory pressure; forward leak detected via buildup > 50 but < 100 cmH2O	warning
`AE0214`	Oxygen PSOL forward leak detected, pressure 50-100 cmH2O	Excessive pressure buildup in blocked inspiratory module during safety valve test	warning
`AE0306`	Test circuit not properly connected or expiratory pressure not detected	Inspiratory and expiratory pressure transducer readings too far apart during leak test	warning
`AE0601`	GUI High Alarm LED fails	CLEAR key pressed to indicate LED not on	warning
`AE0602`	GUI Medium Alarm LED fails	CLEAR key pressed to indicate LED not on	warning
`AE0603`	GUI Low Alarm LED fails	CLEAR key pressed to indicate LED not on	warning
`AE0604`	GUI Normal LED fails	CLEAR key pressed to indicate LED not on	warning
`AE0605`	GUI Batt Backup LED fails	CLEAR key pressed to indicate LED not on	warning
`AE0606`	GUI On Batt Pwr LED fails	CLEAR key pressed to indicate LED not on	warning
`AE0607`	GUI Compressor Ready LED fails	CLEAR key pressed to indicate LED not on	warning
`AE0608`	GUI Compressor Operating LED fails	CLEAR key pressed to indicate LED not on	warning
`AE0609`	GUI 100% O2 LED fails	CLEAR key pressed to indicate LED not on	warning
`AE0610`	GUI Alarm Silence LED fails	CLEAR key pressed to indicate LED not on	warning
`AE0611`	GUI Screen Lock LED fails	CLEAR key pressed to indicate LED not on	warning
`AE0702`	Bad Vent inop LED	EST BD Lamp Test	warning
`AE0703`	Bad SVO LED	EST BD Lamp Test	warning
`AE0704`	Loss of GUI LED fails	Loss of GUI LED not illuminating on backup display unit	warning
`AE1001`	Air PSOL loopback current out of range	Air PSOL (PSOL2) loopback current outside expected range at various drive currents	error
`AE1002`	O2 PSOL loopback current out of range	Oxygen PSOL (PSOL1) loopback current outside expected range at various drive currents	error
`AE1104`	Insp check valve test failed	EST Safety System Test	warning
`AE1201`	Exp valve loopback current out of range	Exhalation valve loopback current outside expected range of drive current at test openings	warning
`AE1305`	Seal test failed	Exhalation valve seal test pressure delta above alert level but below failure level	warning
`AE1600`	Compressor Test - Not installed	EST Compressor Test	info
`AE1601`	Wall air pressure detected when should be disconnected	PS2 pressure switch closed when should be open during compressor test setup	error
`AE1602`	AC power not connected - compressor cannot run	System running on battery power when AC power should be available; BPS charged/charging active	warning
`AE1603`	Compressor pressure not detected	Pressure transducer PC indicates no compressor air present although compressor motor is on	error
`AE1604`	Run mode time OOR	EST Compressor Test	warning
`AE1604`	Compressor run time out of range	Calculated run elapsed time not within acceptable range after 15 s delay	error
`AE1606`	Compressor pressure present after motor disabled	Compressor pressure transducer indicates air present after motor disabled and accumulator drained	error
`AE1607`	Compressor disabled time out of range	Calculated disabled elapsed time not within acceptable range after 15 s delay	error
`AE1608`	Unable to test compressor standby mode	Compressor timer could not be verified as functional in prior run and disabled tests	error
`AE1609`	Compressor standby time out of range	Calculated standby mode elapsed time not within acceptable range; compressor motor still running during standby test phase	error
`AE1610`	Unable to perform compressor load test	EST Compressor Test	warning
`AE1611`	Compressor load test failed - pressure not maintained	Pressure transducer PC indicates compressor unable to maintain minimum pressure during worst-case breath delivery waveform (200 lpm at 45 cmH2O)	error
`AE1700`	Compressor Leak Test - Not installed	EST Compressor Leak Test	info
`AE1701`	Unable to perform compressor leak test	Compressor timer tests not passed during prior Compressor Test	error
`AE1702`	Wall air pressure detected during leak test disable phase	Pressure switch PS2 closed when should be open after disconnecting wall air	error
`AE1703`	Wall air pressure not detected during leak test enable phase	Pressure switch PS2 open when should be closed after reconnecting wall air	error
`AE1704`	Compressor leak detected	Compressor pressure transducer PC indicates loss of compressor pressure during 1-minute observation interval in standby mode, or compressor elapsed time > 1 s in standby	error
`AE1901`	GUI touch: Error	EST GUI Touch Test	warning
`AE2001`	Bad GUI serial port	EST GUI Serial Port Test	warning
`AE2001`	Serial port loopback test failed	In loopback mode, received message did not match transmitted	error
`AE2101`	Backup power supply not fully charged	BPS not fully charged at start of test	error
`AE2102`	Battery pack not discharging	BPS not discharging after AC power disconnected	error
`AE2103`	Bad Backup Power Supply - voltage issue	BPS voltage dropped below accepted level or dropped too quickly during discharge	error
`AE2104`	Battery not charging after AC reconnection	BPS not charging after AC power reconnected (BPS charged bit on and BPS charging bit off)	error
`AE2300`	GUI Nurse Call Test - Not installed	User pressed CLEAR to indicate nurse call device not installed	info
`Air offset out of range`	Air flow sensor calibration failed; measured offset exceeds acceptable range	Calibration procedure detects invalid air sensor offset during Flow Sensor Calibration	error
`Analog Interface Error`		Analog interface failure during POST	error
`APNEA`	Set apnea interval elapsed without triggering a breath	Apnea interval elapsed without ventilator, patient, or operator triggering a breath	warning
`APNEA (lockable)`	No breath triggered within apnea interval	Set apnea interval elapses without patient, ventilator, or operator triggering breath	warning
`AS0010`	Unable to establish O2 flow	Flow controller unable to establish and control oxygen flow at 120 L/min during SST	error
`AS0011`	Unable to establish air flow	Flow controller unable to establish and control air flow at 120 L/min during SST	error
`AS0012`	Oxygen pressure not detected	Only air detected during SST flow sensor test	error
`AS0013`	Wall air pressure not detected	Only oxygen detected during SST flow sensor test	error
`AS0202`	Excessive leak	Pressure drops to 85 cmH2O in 10 s, then in 10 s more by ≥10 cmH2O during SST circuit leak test	error
`AS0202`	Excessive system leak (patient circuit test)	Pressure drops to 85 cmH2O in 10 s, then by ≥ 10 cmH2O in next 10 seconds during patient circuit leak test	error
`AS0206`	Test circuit not connected	Inspiratory and expiratory pressure transducer readings diverge excessively during leak test pressure measurements	warning
`AS0305`	Occluded expiratory filter	Pressure drop across filter 2-3 cmH2O (alert threshold)	warning
`AS0308`	Occluded exhalation compartment	Exhalation compartment pressure >3 cmH2O but <4 cmH2O during SST expiratory filter test	error
`AS0308`	Occluded expiratory compartment	Exhalation compartment pressure >3 but <4 cmH2O	warning
`AS0311`	Low expiratory filter pressure drop	Pressure drop across expiratory filter <0.4 but >0.1 cmH2O	warning
`AS0403`	Occluded inspiratory limb	Inspiratory limb pressure 8.5-12.5 cmH2O (adult) or 5.5-7.5 cmH2O (pediatric)	warning
`AS0406`	Occluded exhalation limb	Expiratory limb pressure 8.5-12.5 cmH2O (adult) or 5.5-7.5 cmH2O (pediatric)	warning
`AS0407`	Peak flow below minimum during circuit test	Peak flow < 80 L/min but > 60 L/min during characterization	warning
`AS0407`	Unable to reach minimum peak flow	Peak flow 60-80 L/min (alert threshold) during inspiratory limb resistance test	warning
`AS0411`	Unable to reach minimum peak flow	Peak flow < alert threshold but > failure threshold during circuit resistance test	warning
`AS0411`	Peak flow below alert threshold	Peak flow below alert threshold during circuit characterization	error
`AS0413`	Insp limb resistance low	Inspiratory limb pressure <0.6 cmH2O (adult) or 5.5 cmH2O (pediatric) but >0.2 cmH2O during SST circuit resistance test	warning
`AS0414`	Expiratory limb resistance low	Expiratory limb pressure 0.2-0.6 cmH2O (adult) or 0.2-0.5 cmH2O (pediatric)	warning
`AS0505`	Patient circuit compliance abnormally high	Compliance > 6 mL/cmH2O (adult) or 4.5 mL/cmH2O (pediatric), < 12/9 mL/cmH2O	error
`AS0505`	Excessive compliance	High compliance >6 mL/cmH2O (adult) or 4.5 mL/cmH2O (pediatric) but <12 mL/cmH2O (adult) or 9 mL/cmH2O (pediatric) during SST compliance calibration test	error
`AS0507`	Compliance low	High compliance falls below 1.56 mL/cmH2O (adult) or 1.34 mL/cmH2O (pediatric) but not lower than 1.05 mL/cmH2O during SST compliance calibration test	error
`AS0509`	Excessive compliance	Low compliance >6 mL/cmH2O (adult) or 4.5 mL/cmH2O (pediatric) but <12 or 9 mL/cmH2O respectively	warning
`AS0509`	Patient circuit compliance abnormally high	Compliance > 6 mL/cmH2O (adult) or 4.5 mL/cmH2O (pediatric), < 12/9 mL/cmH2O	error
`AS0511`	Compliance low	Low compliance <1.56 mL/cmH2O (adult) or 1.34 mL/cmH2O (pediatric) but not below 1.05 mL/cmH2O	warning
`Bad exp valve loopback current`	Exhalation valve loopback current measurement is out of specification during calibration	Exhalation valve calibration detects abnormal loopback current	error
`Both insp and exp autozero failed`	Both inspiration and expiration pressure transducer autozero operations failed during calibration	Autozero calibration step fails for both transducers	error
`Calibration failed: current limit exceeded`	Current supplied to exhalation valve exceeded allowable limit during calibration	Current measurement during exhalation valve calibration exceeds specification	error
`Calibration failed: gain resolution`	Exhalation valve calibration gain adjustment resolution exceeded	During exhalation valve gain calibration step	error
`Calibration failed: gain resolution`	Gain resolution calculation failed during exhalation valve calibration	Calibration algorithm detects gain resolution error	error
`Calibration failed: gain resolution`	DAC gain or resolution measurement out of specification	Calibration gain characterization step	error
`Calibration failed: Pressure build time-out`	Ventilator unable to build required test pressure within expected time during calibration	Pressure build step times out during exhalation valve calibration	error
`Cannot achieve minimum air flow`	System cannot maintain minimum 60 L/min air flow during calibration	Flow Sensor Calibration procedure unable to sustain minimum air flow	error
`Cannot achieve minimum O2 flow`	System cannot maintain minimum 60 L/min oxygen flow during calibration	Flow Sensor Calibration procedure unable to sustain minimum oxygen flow	error
`Cannot program flash`	BDU and/or GUI NOVRAM cannot be successfully programmed	Attempted datakey or serial number programming in service mode	error
`CIRCUIT DISCONNECT`	No ventilation; circuit disconnected	Unintended power loss recovery with circuit disconnect detected; or circuit disconnect detected during operation	critical
`CIRCUIT DISCONNECT (lockable)`	Patient circuit disconnected or sensing failure	Ventilator detects loss of circuit continuity	error
`COMPLIANCE LIMITED VT`	Compliance volume exceeds maximum allowed	Compliance volume required for volume-controlled breath exceeds maximum for 3 of last 4 breaths	warning
`COMPLIANCE LIMITED VT (lockable)`	Excessive compliance volume required for VC breath delivery	Compliance volume required exceeds maximum allowed for 3 of last 4 breaths	warning
`COMPRESSOR INOPERATIVE`	Compressor not operating due to low AC	Compressor unable to operate; low AC power	warning
`Data key is not installed`	Datakey not detected by ventilator	Datakey insertion or boot-up in service mode	error
`DEVICE ALERT`	Background check or POST detected a problem	Power-On Self-Test (POST) or background diagnostic failure	warning
`DRAM Parity Error`	Parity check failure in DRAM	Memory data corruption	error
`DT0002`	Bus error / Access fault	Failure that results in a POST or a reset	critical
`Dxxxxx`	Assertion Background Checks (BD)	Failure that results in a POST or a reset	critical
`Ethernet Parity Error`	Parity check failure in Ethernet	Data corruption in Ethernet transmission	error
`Exhalation pressure transducer autozero failed`	Exhalation pressure transducer DAC count at 0 cmH2O is out of range during autozero	Autozero calibration step fails for exhalation transducer	error
`Exhalation valve temperature out of range`	Exhalation valve temperature outside acceptable operating range during calibration	Temperature sensor reading during calibration	error
`Exxxxx`	Intentional system status event	Status message indicating intentionally caused event	info
`Exxxxx`	Status message from GUI Background Checks	Status message indicating an intentionally caused event	info
`FE0001`	Inspiratory autozero out of range	EST Circuit Pressure Test: Inspiratory pressure transducer ADC count at 0 cmH2O out of range	error
`FE0002`	Expiratory autozero out of range	EST Circuit Pressure Test: Exhalation pressure sensor ADC count at 0 cmH2O out of range	error
`FE0003`	Failed to reach test pressure	Unable to build pressure (air) to 10 cmH2O at 5 L/min within time-out period during EST circuit pressure test	error
`FE0004`	Circuit pressure cross-check failed at 10 cmH2O	Inspiratory and expiratory pressure transducer readings too far apart during 10 cmH2O test	error
`FE0005`	Bad inspiratory autozero solenoid	Inspiratory pressure reading out of range (-0.60 to 0.60 cmH2O) when SOL1 opened	error
`FE0006`	Bad expiratory autozero solenoid	Expiratory pressure reading out of range (-0.60 to 0.60 cmH2O) when SOL2 opened	error
`FE0007`	Cross-check failed: Inspiratory/expiratory pressure transducers too far apart	Test reads inspiratory and expiratory pressure transducers at 50 and 100 cmH2O; readings exceed tolerance	error
`FE0007`	Cross-check failed	Inspiratory/expiratory pressure transducer measurements at 50 or 100 cmH2O test pressure are too far apart	error
`FE0007`	Circuit pressure cross-check failed at 50 and 100 cmH2O	Inspiratory and expiratory pressure transducer readings too far apart during 50 and 100 cmH2O test	error
`FE0008`	Failed to reach test pressure	Unable to build pressure to 50 or 100 cmH2O at 5 L/min within timeout period	error
`FE0010`	AC power not connected	EST Circuit Pressure Test: System running on battery after user prompted to connect AC power	critical
`FE0101`	Oxygen flow sensor cross-check failed	Q1 and Q3 flow sensor readings too far apart at oxygen flows of 120, 60, 5, and 1 L/min	error
`FE0102`	Oxygen PSOL command current out of range	PSOL1 command current out of range at oxygen flows of 120, 60, 5, and 1 L/min	error
`FE0103`	Air flow sensor cross-check failed	Q2 and Q3 flow sensor readings too far apart at air flows of 120, 60, 5, and 1 L/min	error
`FE0104`	Air PSOL command current out of range	PSOL2 command current out of range at air flows of 120, 60, 5, or 1 L/min	error
`FE0106`	Unable to establish O2 flow: Flow controller cannot control oxygen at lower rates	EST test verifies oxygen flow at 60, 5, and 1 L/min; flow controller unable to establish and control	error
`FE0107`	Unable to establish air flow: Flow controller cannot control air at lower rates	EST test verifies air flow at 60, 5, and 1 L/min; flow controller unable to establish and control	error
`FE0108`	O2 zero flow check failed: Oxygen flows when commanded to close	EST commands oxygen PSOL (PSOL1) to 0 L/min (closed); measured oxygen flow > 0.153 L/min	error
`FE0109`	Air zero flow check failed: Air flows when commanded to close	EST commands air PSOL (PSOL2) to 0 L/min (closed); measured air flow > 0.153 L/min	error
`FE0204`	Wall air pressure not detected	ACCEPT key pressed but pressure switch PS2 still open after prompting user to connect wall air	error
`FE0205`	Oxygen pressure not detected	ACCEPT key pressed but pressure switch PS1 still open after prompting user to connect oxygen	error
`FE0206`	O2 pressure detected: PS1 remains closed when oxygen disconnected	EST prompts disconnect oxygen; PS1 should open but remains closed	error
`FE0207`	Air PSOL leak: Excessive pressure buildup > 100 cmH2O in blocked inspiratory module	EST disables compressor, bleeds pressure, reads inspiratory pressure; forward leak detected via buildup > 100 cmH2O	error
`FE0207`	Air PSOL leak	Air PSOL (PSOL2) forward leak detected via excessive pressure buildup (>100 cmH2O) in blocked inspiratory module	error
`FE0208`	Wall air pressure detected: PS2 remains closed when air disconnected	EST disables compressor control and prompts disconnect air; PS2 should open but remains closed	error
`FE0209`	O2 PSOL leak	Oxygen PSOL (PSOL1) forward leak detected via excessive pressure buildup (>100 cmH2O) in blocked inspiratory module	error
`FE0210`	Safety valve pressure relief failed	Multiple test failures: (1) stable 1 L/min flow not established with patient port blocked; (2) safety valve cracking pressure out of range; (3) neither PSOL could deliver 100 L/min within prescribed count; (4) peak pressure too high during PSOL test	error
`FE0210`	SV pressure relief failed: Safety valve cracking pressure out of range or flow not established	EST tests safety valve cracking pressure and/or establishes flow to patient port; pressure or flow out of specification	error
`FE0211`	Oxygen pressure not detected	PS1 (oxygen pressure switch) reads open when oxygen should be connected	error
`FE0212`	Compressor pressure detected during EST depressurization test	Compressor pressure transducer indicates non-zero pressure when should be depressurized	error
`FE0215`	Air zero flow check failed	During zero-flow check, air flow sensor (Q2) reads > 0.05 L/min	error
`FE0216`	O2 zero flow check failed	During zero-flow check, oxygen flow sensor (Q1) reads > 0.05 L/min	error
`FE0217`	Exhalation zero flow check failed, Q3 >0.1 L/min	Exhalation flow sensor reads excessive flow during zero-flow test with supplies disconnected	error
`FE0301`	Excessive leak in EST Leak Test	System pressure dropped below failure pressure level during leak test	error
`FE0301`	Excessive system leak detected during leak test	System pressure dropped below 85 cmH2O or drops ≥5 cmH2O within 10 seconds	error
`FE0305`	Unable to establish pressure in EST Leak Test	System cannot attain leak test starting pressure within time-out period	error
`FE0401`	Accept key fails in GUI Keyboard Test	Wrong key pressed or key not pressed within 15 seconds during EST	warning
`FE0402`	Clear key fails in GUI Keyboard Test	Wrong key pressed or key not pressed within 15 seconds during EST	warning
`FE0403`	Insp. Pause key fails in GUI Keyboard Test	Wrong key pressed or key not pressed within 15 seconds during EST	warning
`FE0404`	Exp. Pause key fails in GUI Keyboard Test	Wrong key pressed or key not pressed within 15 seconds during EST	warning
`FE0405`	Man Insp key fails in GUI Keyboard Test	Wrong key pressed or key not pressed within 15 seconds during EST	warning
`FE0405`	Manual Inspiration key fails during EST keyboard test	Man Insp key not pressed or wrong key pressed within 15 seconds	error
`FE0406`	100% O2/CAL key fails in GUI Keyboard Test	Wrong key pressed or key not pressed within 15 seconds during EST	warning
`FE0407`	Info key fails in GUI Keyboard Test	Wrong key pressed or key not pressed within 15 seconds during EST	warning
`FE0408`	Alarm Reset key fails in GUI Keyboard Test	Wrong key pressed or key not pressed within 15 seconds during EST	warning
`FE0409`	Alarm Silence key fails in GUI Keyboard Test	Wrong key pressed or key not pressed within 15 seconds during EST	warning
`FE0410`	Alarm Volume key fails in GUI Keyboard Test	Wrong key pressed or key not pressed within 15 seconds during EST	warning
`FE0411`	Screen brightness fails in GUI Keyboard Test	Wrong key pressed or key not pressed within 15 seconds during EST	warning
`FE0412`	Screen contrast key fails in GUI Keyboard Test	Wrong key pressed or key not pressed within 15 seconds during EST	warning
`FE0413`	Screen lock key fails in GUI Keyboard Test	Wrong key pressed or key not pressed within 15 seconds during EST	warning
`FE0501`	Knob not responding	Knob not turned in prompted direction within 15 seconds	error
`FE0501`	Bad knob	EST GUI Knob Test - knob not turned in direction as prompted within 15 s	warning
`FE0501`	Knob rotation not detected during EST knob test	Knob not turned in commanded direction within 15 seconds	error
`FE0801`	SAAS (Safety Audible Alarm System) test failed	GUI alarm sound not heard during diagnostic test or cable disconnected	critical
`FE0801`	SAAS (Safety Audible Alarm System) test failed in GUI Audio Test	CLEAR key pressed to indicate GUI audio diagnostic failed	error
`FE0901`	Bad alarm cable in BDU Audio Test	Alarm cable voltage out of range (< 3.5 or > 5.05 V)	error
`FE0902`	Bad power fail capacitor (initial) in BDU Audio Test	Power failure capacitor initial voltage out of range (< 4.5 or > 5.05 V)	error
`FE0903`	Bad power fail capacitor (final) in BDU Audio Test	Power failure capacitor final voltage out of range or RC constant < 60 s	error
`FE0904`	Bad BD audio in BDU Audio Test	CLEAR key pressed to indicate user did not hear alarm although alarm was active	error
`FE0904`	BD alarm unit not sounding or responding	Self-test sounds alarm; user presses CLEAR indicating no audible alarm heard	error
`FE1101`	Safety valve occluded in Safety System Test	Excessive safety valve back pressure when safety valve is open	critical
`FE1102`	Bad safety valve driver or loopback in Safety System Test	Safety valve loopback current out of range during timed test points	error
`FE1103`	Insp check valve test failed in Safety System Test	Took too long to relieve excess pressure through open safety valve, indicating inspiratory check valve occluded or test circuit too large	error
`FE1105`	Unable to establish flow in Safety System Test	Flow controller unable to establish and control gas flow at 60 L/min	error
`FE1301`	Seal test failed	Exhalation valve seal test pressure delta exceeds failure threshold	critical
`FE1301`	Seal test failed in Exp Valve Seal Test	Seal test delta pressure above failure level	error
`FE1302`	Exp valve temp OOR in Exp Valve Seal Test	Exhalation valve magnet temperature out of range (10 to 100 degrees C)	warning
`FE1302`	Exp valve temp out of range	Exhalation valve magnet temperature outside 10-100 °C range during warmup diagnostic	warning
`FE1303`	Unable to establish exp flow	Exhalation flow controller cannot establish/maintain 5 L/min air flow with 45 cmH2O system pressure	critical
`FE1304`	Exp valve not calibrated in Exp Valve Seal Test	Exhalation valve table checksum invalid or last calibration not completed successfully	error
`FE1401`	Bad calibration	Measured system pressure at one or more exhalation test points is out of range	error
`FE1401`	Bad calibration in Exp Valve Test	Measured system pressure at one or more test points out of range	error
`FE1402`	Exp valve not calibrated in Exp Valve Test	Exhalation valve table checksum invalid or last calibration not completed successfully	error
`FE1403`	Unable to establish exp flow in Exp Valve Test	Flow controller unable to establish and control air flow measured by exhalation flow sensor Q3	error
`FE1501`	Unable to establish air flow in Exp Heater Test	Flow controller unable to establish and control 60 L/min air flow	error
`FE1502`	Bad exp heater	EST Exp Heater Test failure - exhalation heater temperature did not rise sufficiently when heater turned on	error
`FE1502`	Bad exp heater in Exp Heater Test	Exhalation heater temperature did not rise sufficiently when heater was turned on	error
`FE1503`	Bad exp heater (cooling) in Exp Heater Test	Heater temperature did not drop sufficiently during interval after heater turned off	error
`FE1503`	Bad exhalation heater - insufficient temperature drop	Heater temperature did not drop ≥ 2 °C from heater-on temperature during interval after heater turned off	error
`FE2201`	Low exp ∆P	EV Velocity Transducer Test - expiratory delta pressure too low, indicating velocity transducer not responding properly	warning
`FE2201`	Low exp delta P	EV Velocity Transducer Test failure - expiratory delta P too low; velocity transducer not responding properly	error
`FE2201`	Low exp delta P in EV Velocity Transducer Test	Expiratory delta pressure too low, indicating velocity transducer not responding properly	error
`FE2301`	Nurse call stuck on in GUI Nurse Call Test	CLEAR key pressed to indicate nurse call (remote alarm) relay stuck on when should be off	error
`FE2302`	Nurse call stuck off in GUI Nurse Call Test	CLEAR key pressed to indicate nurse call (remote alarm) relay stuck off when should be on	error
`Flow sensor cross-check failed`	Exhalation air flow out of specification relative to inspiration test flow	Flow measurement comparison during calibration cross-check	error
`Flow sensor cross-check: unable to establish flow`	Air flow sensor unable to detect 5 L/min test flow during cross-check	Flow controller test during exhalation valve calibration	error
`Flow sensor info invalid`	Flow sensor calibration table checksum error during exhalation valve calibration	Checksum verification of flow sensor calibration table fails	error
`FS0001`	O2 flow sensor cross check failed in SST Flow Sensor Test	Oxygen flow sensor (Q1) cross-check failed during self-service test	error
`FS0002`	O2 PSOL current out of range in SST Flow Sensor Test	Oxygen PSOL (PSOL1) command current out of range with respect to oxygen flow sensor Q1	error
`FS0003`	Air flow sensor cross check failed in SST Flow Sensor Test	Air flow sensor (Q2) cross-check failed during self-service test	error
`FS0004`	Air PSOL current out of range in SST Flow Sensor Test	Air PSOL (PSOL2) command current out of range with respect to air flow sensor Q2	error
`FS0005`	Gas not connected in SST Flow Sensor Test	No gas available (neither PS1, PS2, nor PC detects pressure)	warning
`FS0006`	Unable to establish O2 flow	SST Flow Sensor Test - flow controller unable to establish and control oxygen flow at 60, 5, and 1 L/min	critical
`FS0007`	Unable to establish air flow	SST Flow Sensor Test - flow controller unable to establish and control air flow at 60, 5, and 1 L/min	critical
`FS0008`	Oxygen zero flow check failed	Oxygen flow exceeds 0.153 L/min when PSOL1 is commanded to deliver 0 L/min (closed)	error
`FS0009`	Air zero flow check failed	Air flow > 0.153 L/min when PSOL2 commanded closed	error
`FS0101`	Inspiratory autozero out of range	Inspiratory pressure transducer ADC count at 0 cmH2O is outside acceptable range during autozero calibration	error
`FS0102`	Expiratory autozero out of range	Expiratory pressure transducer ADC count at 0 cmH2O is outside acceptable range during autozero calibration	error
`FS0103`	Failed to reach test pressure at 10 cmH2O	System unable to pressurize to 10 cmH2O at 5 L/min flow within timeout period	error
`FS0104`	Pressure cross-check failed at 10 cmH2O	Inspiratory and expiratory pressure transducer readings diverge beyond acceptable tolerance at 10 cmH2O test pressure	error
`FS0105`	Bad inspiratory autozero solenoid	Inspiratory pressure reading outside range (-0.60 to 0.60 cmH2O) when autozero solenoid (SOL1) commanded open	error
`FS0106`	Bad expiratory autozero solenoid	Expiratory pressure reading outside range (-0.60 to 0.60 cmH2O) when autozero solenoid (SOL2) commanded open	error
`FS0107`	Pressure cross-check failed at 50 and 100 cmH2O	Inspiratory and expiratory pressure transducer readings diverge beyond acceptable tolerance at high pressure levels (50 and 100 cmH2O)	error
`FS0108`	Failed to reach high test pressure (50 or 100 cmH2O)	System unable to pressurize to 50 or 100 cmH2O at 5 L/min flow within timeout period	error
`FS0201`	Excessive system leak detected	System pressure drops below 85 cmH2O or drops by ≥ 30 cmH2O over 20 seconds during leak test	error
`FS0205`	Unable to establish pressure	Unable to attain leak test starting pressure within timeout period using oxygen or air	error
`FS0301`	Unable to establish flow	System cannot deliver stable 60 L/min gas flow	error
`FS0303`	Occluded expiratory compartment	Exhalation compartment pressure >4 cmH2O	error
`FS0304`	Occluded expiratory filter	Pressure drop across expiratory filter > 3 cmH2O	error
`FS0306`	Patient circuit not disconnected	Expiratory flow detected during circuit disconnection test	error
`FS0307`	Patient circuit not reconnected	Expiratory flow reading indicates circuit not reconnected after test	error
`FS0310`	Low expiratory filter pressure drop	Pressure drop across expiratory filter <0.1 cmH2O	error
`FS0401`	Unable to establish flow	Flow controller cannot establish and maintain gas flow during inspiratory limb test	error
`FS0402`	Occluded inspiratory limb	Inspiratory limb pressure > 12.5 cmH2O (adult) or 7.5 cmH2O (pediatric)	error
`FS0404`	Unable to reach minimum peak flow	Peak flow < 60 L/min during inspiratory limb resistance test	error
`FS0405`	Occluded exhalation limb	Expiratory limb pressure > 12.5 cmH2O (adult) or 7.5 cmH2O (pediatric)	error
`FS0408`	Inspiratory limb resistance low	Inspiratory limb pressure <0.2 cmH2O	error
`FS0409`	Expiratory limb resistance low	Expiratory limb pressure < 0.2 cmH2O	error
`FS0410`	Unable to reach minimum peak flow	Peak flow falls below failure threshold during circuit resistance characterization	error
`FS0412`	Wye not blocked	Unable to pressurize system to 100 cmH2O at 60 L/min within timeout	error
`FS0501`	Unable to pressurize circuit	System cannot reach one or more test pressure points during compliance measurement	error
`FS0502`	Unable to pressurize circuit	System cannot pressurize to test pressure points during high-flow compliance test	error
`FS0503`	Compliance calculation failure	Out-of-range pressure ratio calculation during compliance measurement	error
`FS0504`	Excessive compliance	High compliance >12 mL/cmH2O (adult) or 9 mL/cmH2O (pediatric)	error
`FS0506`	Compliance low	High compliance falls below 1.05 mL/cmH2O	error
`FS0508`	Excessive compliance	Low compliance >12 mL/cmH2O (adult) or 9 mL/cmH2O (pediatric)	error
`FS0510`	Compliance low	Low compliance < 1.05 mL/cmH2O	error
`↑fTOT`	Total respiratory rate at or above set limit (updated at each inspiration)	Total respiratory rate ≥ set limit, updated at beginning of each inspiration	warning
`↑fTOT (High Respiratory Rate Total)`	Total respiratory rate at or above set alarm limit	Measured respiratory rate ≥ set limit	warning
`HN0001`	Non-maskable interrupt (NMI): DRAM Parity Error	BDU reset triggered by DRAM parity error	critical
`HN0002`	NMI: Ethernet Parity Error	BDU reset triggered by Ethernet parity error	critical
`HN0016`	NMI: Analog Interface Error (ADC Channel Sequencer Fault)	Non-maskable interrupt from ADC channel sequencer fault	critical
`HN0016_ATF`	NMI: Analog Interface Error - ADC Timing Fault	BDU reset triggered by ADC timing fault	critical
`HN0016_CSF`	NMI: Analog Interface Error - ADC Channel Sequencer Fault	BDU reset triggered by ADC channel sequencer fault	critical
`HN0016_HDF`	NMI: Analog Interface Error - Hamming Decode Fault	BDU reset triggered by Hamming decode fault	critical
`HN0080`	NMI: Analog Interface Error - ADC Timing Fault	BDU reset triggered by ADC timing fault	critical
`HN0129`	NMI: DRAM Parity Error	Non-maskable interrupt from DRAM parity error	critical
`HN0130`	NMI: Ethernet Parity Error	Non-maskable interrupt from Ethernet parity error	critical
`INOPERATIVE BATTERY`	Backup Power System (BPS) installed but not functioning	BPS detected but fails initialization or operation test	warning
`Inspiration autozero failed`	Inspiration pressure transducer DAC count at 0 cmH2O is out of range during autozero	Autozero calibration step fails for inspiration transducer	error
`INSPIRATION TOO LONG`	Inspiratory time for spontaneous breath exceeds IBW-based limit	Inspiratory time for spontaneous breath ≥ IBW-based limit	warning
`INSPIRATION TOO LONG (lockable)`	Spontaneous breath inspiratory time exceeds ideal body weight (IBW) limit	Inspiratory time for spontaneous breath ≥IBW-based limit	warning
`KB0001`	Bad safety valve switched side	Measured voltage on safety valve switched side indicates valve is not in expected state	critical
`KB0002`	Bad expiratory flow	Exhalation flow sensor (Q3) reading out of range	critical
`KB0003`	Bad O2 PSOL current	Oxygen PSOL (PSOL1) current out of range	critical
`KB0004`	Bad air PSOL current	Air PSOL (PSOL2) current out of range	critical
`KB0005`	Bad exp motor current	Current to exhalation valve motor out of range	critical
`KB0007`	Bad exp pressure	PE (expiratory pressure) reading out of range	critical
`KB0008`	Bad insp pressure	PI (inspiratory pressure) reading out of range	critical
`KB0009`	Air flow out of range HIGH	Q2 (air flow sensor) reading too high	critical
`KB0012`	O2 flow out of range HIGH	Q1 (oxygen flow sensor) reading too high	critical
`KB0016`	Bad BD 10V supply	BDU +10 V supply out of range	critical
`KB0017`	Bad BD 12 V supply	BDU +12V supply out of range	critical
`KB0018`	Bad BD 15 V supply	BDU +15V supply out of range	critical
`KB0019`	Bad BD -15 V supply	BDU background check detects -15 V supply out of range	critical
`KB0022`	Bad BD 5 V supply	BDU background check detects +5 V supply out of range	critical
`KB0023`	O2 PSOL stuck	Oxygen PSOL (PSOL1) command current out of range	critical
`KB0024`	Air PSOL stuck	Air PSOL (PSOL2) command current out of range	critical
`KB0025`	Air PSOL stuck open	Air PSOL (PSOL2) command current reading indicates solenoid cannot close	critical
`KB0026`	O2 PSOL stuck open	Oxygen PSOL (PSOL1) command current reading indicates solenoid cannot close	critical
`KB0030`	Bad safety valve current	Safety valve solenoid current out of range during BDU check	critical
`KB0031`	Insp pressure stuck	Inspiratory pressure transducer (PI) reading stuck during BDU check	critical
`KB0032`	Exp pressure stuck	Expiratory pressure transducer (PE) reading stuck during BDU check	critical
`KB0033`	Insp pressure autozero offset failed	Inspiratory pressure transducer (PI) reading following autozero out of range	critical
`KB0034`	Exp pressure autozero offset failed	Expiratory pressure transducer (PE) reading following autozero out of range	critical
`KB0037`	Analog-Digital converter failed high	Analog-to-digital converter failure during BDU check	critical
`KB0038`	Analog-Digital converter failed low	Analog-to-digital converter failure during BDU check	critical
`KB0039`	Analog-Digital loopback failed	ADC loopback test failure during BDU check	critical
`KB0044`	BD NOVRAM checksum error	BD NOVRAM (non-volatile RAM) checksum validation fails during BDU check	critical
`KB0053`	BD EEPROM checksum error	BD EEPROM (non-volatile memory) checksum validation fails during BDU check	critical
`KB0064`	LV Ref out of range	Low-voltage reference circuit reading out of specification during BDU check	critical
`KB0065`	SV current out of range	Safety valve solenoid current out of specification during BDU check	critical
`KB0076`	Task Monitor	Task monitor function failure during BDU check	critical
`KB0079`	BK vent inop occurred	BDU detects ventilator inoperative signal active from GUI; indicates GUI has declared vent inoperative	critical
`KB0082`	Watchdog failure occurred	BD CPU watchdog timer failed during BDU check	critical
`KP0001`	Processor Initialization test failed	Phase 1 POST processor initialization fails	error
`KP0002`	Integer Unit test failed	Phase 1 POST general CPU confidence test fails	error
`KP0003`	DRAM Refresh Timer Test	POST detects DRAM refresh circuit failure	critical
`KP0004`	Kernel DRAM Test	POST detects kernel DRAM memory failure	critical
`KP0005`	Boot EPROM Checksum Test	POST detects EPROM checksum validation failure	critical
`KP0006`	POST Phase 2 Initialization	POST Phase 2 initialization sequence failure	critical
`KP0007`	Addressing Mode Test	POST detects CPU addressing mode test failure	critical
`KP0008`	Kernel NOVRAM Test	POST detects kernel NOVRAM test failure	critical
`KP0009`	Rolling Thunder Test	POST has started but not completed three or more times for reasons unrelated to power failure	critical
`KP0011`	Time of Day Clock Test failed (Major)	Fails during Phase 1 kernel POST	critical
`KP0012`	Timer Test	Timer failed comparison with real-time clock or failed to generate interrupt	critical
`KP0013`	Watchdog Timer Test	POST detects watchdog timer did not time out as expected	critical
`KP0015`	FLASH Memory Checksum Test	POST detects FLASH memory checksum validation failure	critical
`KP0081`	Memory Management Unit Test	POST detects memory management unit (MMU) circuit failure	critical
`KP0082`	Bus Timer Test	Local bus activity has ceased or bus time-out circuit did not generate expected interrupt	critical
`KP0083`	NMI Source Register Test	POST detects non-maskable interrupt (NMI) source register test failure	critical
`KP0084`	DRAM Memory test failed	Phase 2 POST DRAM data pattern verification fails	error
`KP0084`	POST DRAM Test	POST detects DRAM memory failure during POST sequence	critical
`KP0085`	Ethernet Self-Test start failed	Phase 2 POST Ethernet controller initial verification fails	error
`KP0087`	Unexpected Reset Umpire Test	POST has been invoked three times within 24 operational hours due to unexpected resets	critical
`KP0089`	Floating Point Unit Test	POST detects floating-point math unit failure	critical
`KP0090`	DRAM Parity Circuit Test	POST detects DRAM parity error detection circuit failure	critical
`KP0112`	VENT INOP Test failed	Ventilator in VENT INOP state	critical
`KP0113`	Analog Interface PCB Test	POST detects AI PCB circuit test failure	critical
`KP0114`	ADC Test	POST detects ADC (analog-to-digital converter) data not available to CPU as expected	critical
`KP0115`	DAC Test	POST detects DAC (digital-to-analog converter) output data not as expected	critical
`KP0116`	BDU POST analog devices test failure; check specific channel per address	BDU POST analog devices test (Phase 2) failure	critical
`KP0116`	BDU POST analog device test failure	Analog device failure during BDU POST Phase 2	critical
`KP0117`	BD Serial Device Test	POST detects serial communication device test failure	critical
`KP0120`	Safe State System Test	POST detects failure to place PSOLs and exhalation valve into safe state or verify they cannot be commanded	critical
`KP0128`	Download operating system (OS) Boot	POST detects OS boot download failure	critical
`KP0129`	Operating System Initialization failed	OS fails to load	critical
`KP0129`	Application OS Boot	POST detects application OS boot failure	critical
`KP0130`	PB-MON Boot	POST detects PB-MON (monitoring application) boot failure	critical
`KP0131`	Application Boot	POST detects main application boot failure	critical
`LB0006`	Bad exhalation valve coil temp	Background check detects exhalation valve coil temperature out of range	warning
`LB0010`	Air flow out of range LOW	Background check detects air flow sensor (Q2) reading too low	warning
`LB0011`	Air flow sensor thermistor out of range	Background check detects Q2 thermistor reading out of range	error
`LB0011`	Bad air flow temperature	Air flow sensor Q2 thermistor reading out of range	unknown
`LB0013`	O2 flow measurement below specification	Oxygen flow sensor (Q1) reading too low	error
`LB0013`	Oxygen flow sensor reading too low	Background check detects Q1 reading below range	error
`LB0014`	Oxygen flow sensor thermistor out of range	Background check detects Q1 thermistor reading out of range	error
`LB0014`	Bad O2 flow temp	Oxygen flow sensor Q1 thermistor reading out of range	unknown
`LB0015`	Expiratory flow sensor thermistor out of range	Background check detects Q3 thermistor reading out of range	error
`LB0015`	Expiratory flow sensor thermistor reading out of range	Expiratory flow sensor (Q3) thermistor malfunction	error
`LB0020`	GUI +12V supply out of range	Background check detects supply voltage out of range	error
`LB0020`	GUI +12V supply voltage out of specification	GUI +12V power supply voltage out of range	error
`LB0021`	GUI +5V supply out of range	Background check detects supply voltage out of range	error
`LB0021`	GUI +5V supply voltage out of specification	GUI +5V power supply voltage out of range	error
`LB0027`	Atmospheric pressure transducer reading out of specification	Atmospheric pressure sensor malfunction	error
`LB0027`	Atmospheric pressure transducer reading out of range	Background check detects pressure reading out of range	error
`LB0028`	Bad O2 sensor OOR	Oxygen sensor percentage reading out of range	unknown
`LB0028`	Oxygen sensor percentage reading out of range	Background check detects sensor reading outside limits	error
`LB0029`	Oxygen sensor alert was reset	Background check status message	info
`LB0035`	Power fail capacitor voltage out of range	Background check detects capacitor voltage outside limits	error
`LB0036`	Alarm cable voltage out of range	Background check detects cable voltage anomaly	error
`LB0039`	ADC loopback constant test failure	Background check detects ADC loopback failure	error
`LB0043`	Power switch is in off state but power monitoring signal not detected	Power switch failure; switch appears off but power fail NMI not triggered	error
`LB0043`	Power switch appears stuck	Background check detects switch in off state but power fail NMI did not occur	error
`LB0045`	Real-time clock failure	Background check detects BD time of day failure	error
`LB0048`	Backup power supply voltage out of range	Background check detects BPS voltage anomaly	error
`LB0049`	Backup power supply current out of range	Background check detects BPS current anomaly	error
`LB0050`	Backup power supply model information incorrect	Background check detects wrong BPS model data	error
`LB0051`	Exhalation heater thermistor reading out of range	Background check detects heater thermistor anomaly	error
`LB0051`	Bad exp heater	Exhalation heater thermistor reading out of range	unknown
`LB0056`	Compressor elapsed timer error	Compressor timer failure	unknown
`LB0057`	Compressor EPROM data corruption	Background check detects unexpected EPROM data	error
`LB0058`	Loss of communication with GUI	Background check detects BD-GUI communication failure	error
`LB0060`	Resume GUI communication	Communication with GUI was resumed	unknown
`LB0060`	Communication with GUI has been restored	Background check status message	info
`LB0062`	EST required but not run	Background check detects user powered into normal mode without running EST	error
`LB0062`	EST (Equipment Self Test) required but not run	User powered on in normal mode instead of service mode when EST was needed	error
`LB0075`	Data key update failed	Background check detects data key update failure	error
`LB0076`	Task monitor alert	Background check detects task monitoring anomaly	warning
`LB0080`	Breath delivery extended beyond expected time	Background check detects breath delivery timing fault	critical
`LB0083`	GUI communication initialized and resumed	Background check initialization status message	info
`LB0083`	Initialization: GUI communication resumed	GUI communication restored during power-up sequence	info
`LB0085`	GUI communication lost during initialization	Background check initialization status message	info
`LB0085`	Initialization: GUI communication lost	GUI communication lost during power-up sequence	info
`LB0087`	Compressor serial number updated	Background check status message	info
`LB0088`	10000 hours stored for elapsed time	Compressor hours corrupted; 10000 hour limit reached	unknown
`LB0088`	Compressor hours corrupted (10000 hours stored)	Background check detects elapsed time corruption	error
`LB0089`	Cannot determine data key size	Background check detects data key read failure	error
`LB0092`	Battery event status indication	Background check detects battery state change	warning
`LB0092`	Battery Event alert related to backup power supply status	Backup power supply event detected	error
`LC1xxx`	Communications error between BD and peripheral devices	Serial or network communication failure with external devices	error
`LCxxxx`	Network communications error between BDU and GUI	Communications error detected with variable code suffix	error
`LOSS OF POWER`	Insufficient AC and BPS power; independent audio alarm sounds	Power switch on but insufficient AC and BPS power combined	critical
`LOW AC POWER`	AC power dropped below 80% of nominal for 1 s	Mains (AC) power <80% of nominal for ≥1 s	warning
`LOW BATTERY`	Battery Backup Power remaining < 2 minutes	BPS operational time falls below approximately 2 minutes	warning
`LOW BATTERY`	Battery has <2 minutes of operational time remaining	BPS operational time <2 minutes	warning
`LOW INSP PRESSURE`	Inspiratory target pressure below minimum required (VC+ breath)	Inspiratory target pressure <(PEEP + 5 cmH2O) when mandatory type is VC+	warning
`LOW INSP PRESSURE (lockable)`	Inspiratory target pressure below minimum safe level	Inspiratory target pressure < (PEEP + 5 cmH2O) when breath type VC+	warning
`LP0008`	Non-critical NOVRAM data failure during startup	NVRAM self-test detected non-critical data corruption	error
`LP0008`	Kernel NOVRAM data failure (noncritical)	POST (BD) detects noncritical NOVRAM data anomaly	error
`LP0010`	Interrupt controller test failure	POST (BD) detects interrupt controller fault	critical
`LP0011`	Time of Day Clock test failed (minor)	Phase 1 POST Time of Day clock functionality verification fails	warning
`LP0085`	Ethernet self-test start	POST (BD) ethernet diagnostics begin	critical
`LP0086`	Ethernet Self-Test end status failed	Phase 2 POST Ethernet controller final status check fails	warning
`LP0087`	Unexpected reset detected (watchdog timeout)	POST (BDU) invoked due to watchdog time-out	error
`LP0088`	NOVRAM data failure detected during POST	Non-critical NVRAM data corruption during self-test	error
`LP0088`	POST NOVRAM test failure (noncritical)	POST (BDU) detects noncritical NOVRAM data anomaly	error
`LP0112`	Ventilator INOP signal in unexpected state	POST (BDU) detects VENT INOP signal fault	critical
`LP0114`	ADC (analog-to-digital converter) test failure	POST (BD) detects ADC fault	critical
`LP0114`	ADC Test	Analog to Digital Converter test failure	unknown
`LP0115`	DAC (digital-to-analog converter) test failure	POST (BD) detects DAC fault	critical
`LP0115`	DAC Test	Digital to Analog Converter test failure	unknown
`LP0116`	BDU POST analog device test failure	Analog device failure during BDU POST	critical
`LP0116`	GUI analog devices test failure; check specific channel per address	Analog devices test (Phase 2) failure at GUI	critical
`LP0121`	Service switch appears to be stuck closed	POST (BDU) detects service switch stuck	error
`LP0122`	AC Voltage Test failed	AC monitor voltage outside specified range	warning
`LP0122`	AC input voltage outside nominal range	POST (BDU) detects AC monitor voltage not within ±20% of set nominal	error
`No air connected`	Air supply pressure not detected during calibration	Air supply pressure switch check at calibration start	error
`No air connected`	Wall and compressor air pressure switches detect no air connected to ventilator	Air pressure switches report no air supply during calibration	critical
`NO AIR SUPPLY`	Air inlet filter blocked or air source disconnected; compressor inoperative	Air pressure switch fails to detect supply pressure after system startup	warning
`NO AIR SUPPLY`	Air supply unavailable; ventilator delivers 100% oxygen or only O2 available	Air inlet pressure loss; compressor inoperative; safety valve open	critical
`No O2 connected`	Oxygen supply is not detected; calibration cannot proceed without oxygen	Oxygen pressure switch (PS1) detects no oxygen connected during calibration setup	error
`NO O2 SUPPLY`	Oxygen source lost or inlet filter blocked	O2 pressure switch fails to detect oxygen pressure	warning
`NO O2 SUPPLY`	Oxygen supply unavailable; ventilator delivers 21% or only air available	Oxygen inlet pressure loss; safety valve open	critical
`↑O2%`	Measured O2% 7% or more above set value	O2% measured ≥7% above setting for ≥30 s (12% during first hour; +5% for 4 min after decrease)	warning
`↓O2%`	Measured O2% 7% or more below set value or below 18%	O2% measured ≤7% below setting for ≥30 s (or ≤12% during first hour; +5% for 4 min after increase) or <18%	error
`↑O2% (High O2%)`	Measured oxygen percentage above set limit	Measured O2% ≥7% above set O2% for ≥30 s (or ≥12% in first hour)	warning
`↓O2% (Low O2%)`	Measured oxygen percentage below set limit	Measured O2% ≤7% below set O2% for ≥30 s, or below 18%	error
`O2 offset out of range`	Oxygen flow sensor calibration failed; measured offset exceeds acceptable range	Calibration procedure detects invalid oxygen sensor offset during Flow Sensor Calibration	error
`O2 SENSOR`	O2 sensor out of calibration or sensor failure	Sensor output falls outside acceptable range or sensor not responding	warning
`Operating on battery`	Ventilator is powered by internal BPS battery; AC power unavailable	AC input voltage drops below +80 V AC equivalent	warning
`Operational time < 2 minutes`	Less than 2 minutes of battery power remains; critical low-battery condition	BPS discharge reaches point where only 2 minutes of powered operation remain	critical
`↓PCOMP`	↓PPEAK detected but not ↓PCOMP; target pressure not met	Target pressure <(↓PPEAK - 5 cmH2O)	warning
`↑PMEAN`	Measured airway pressure at or above set limit	Measured airway pressure ≥ set limit	warning
`↑PMEAN (lockable)`	Mean airway pressure at or above set limit	Measured airway pressure ≥ set limit	warning
`POST Internal Software Failure`	POST internal software error	Software logic failure	error
`Power Fail NMI`	Power failure during POST (BDU only)	Loss of AC power during POST	critical
`↑PPEAK`	Peak inspiratory pressure detected; not compliance	↑PPEAK detected and NOT ↓PCOMP	warning
`↑PPEAK (lockable)`	Peak inspiratory pressure at or above set limit	Peak pressure detected exceeds set limit	warning
`Pressure sensor cross-check alert: approaching spec limit`	Pressure cross-check alert at one or more test pressures without failures	Pressure measurement during five-point pressure cross-check (5, 25, 50, 75, 100 cmH2O)	warning
`Pressure sensor cross-check failed`	Pressure transducer cross-check failed at one or more of five test pressures	Pressure measurement comparison at 5, 25, 50, 75, or 100 cmH2O during calibration	error
`Pressure sensor cross-check: unable to build pressure`	System unable to pressurize to one or more of five test pressures	Pressurization algorithm test sequence during calibration	error
`PROCEDURE ERROR`	Patient connected before setup procedure complete	Patient circuit connected while ventilator startup sequence incomplete	warning
`↑PVENT`	Inspiratory pressure >100 cmH2O; VC breath type	Inspiratory pressure >100 cmH2O and mandatory type = VC	error
`↑PVENT (lockable)`	Inspiratory pressure exceeds 100 cmH2O with volume control breath	Inspiratory pressure > 100 cmH2O and breath type VC	error
`SAAS NMI`	GUI alarm or alarm cabling interrupt	Alarm system anomaly	warning
`SCREEN BLOCK`	Possible blocked beam on display GUI or touch screen malfunction	Display not responding or sensor detecting obstruction	info
`Serial number(s) doesn't match the data key`	Inserted datakey does not match ventilator serial numbers; invalid datakey	Datakey insertion when serial numbers were initialized with different datakey	warning
`SEVERE OCCLUSION`	Severe obstruction in ventilator circuit preventing ventilation	Ventilator detects very low or no flow despite pressure generation	critical
`SEVERE OCCLUSION`	Little or no ventilation; ventilator in occlusion status cycling (OSC)	Severe circuit or patient airway occlusion detected	critical
`Sxxxxx`	Status message indicating intentional event	Background check status code	info
`Sxxxxx`	Status	Intentionally caused event	unknown
`U04004`	Assertion failure from intermittent digital I/O connection	Intermittent connection to digital I/O line detected	error
`U04004`	Assertion failure (I/O intermittent fault)	Background check GUI detects I/O connection anomaly	warning
`U05013`	Assertion failure (I/O intermittent fault)	Background check GUI detects I/O connection anomaly	warning
`U05013`	Assertion failure from intermittent digital I/O connection	Intermittent connection to digital I/O line detected	error
`U08002`	Serial data buffer overflow from host device	Background check BDU detects excessive serial errors	error
`U08002`	Assertion failure from GUI data buffer overflow	GUI overloaded with invalid data from serial port; host transmitting bad data causing over-run, parity, or framing errors	error
`U08012`	Assertion failure generating soft reset	Background check GUI detects anomaly	warning
`U08012`	Assertion failure; GUI generates soft reset to resynchronize	GUI detects error condition and initiates soft reset	error
`U14019`	Assertion failure generating soft reset	Background check GUI detects anomaly	warning
`U14019`	Assertion failure; GUI generates soft reset to resynchronize	GUI detects error and initiates soft reset	error
`U14021`	Assertion Failure - Background check (GUI)	Time stamps between GUI and BD are out of sync	warning
`Unable to burn flash`	GUI NOVRAM cannot be successfully programmed	Cal Info Duplication function cannot write calibration data to GUI NOVRAM	error
`Unable to establish flow`	Flow controller unable to establish 5 L/min test flow via exhalation flow sensor	Exhalation flow controller test during calibration	error
`Unable to program flash`	Calibration table data unable to write to BDU NOVRAM	Calibration completion when storing results to non-volatile memory	error
`Unable to program flash`	BDU NOVRAM cannot be successfully programmed	Initialize Flow Sensor function cannot write calibration data to BDU NOVRAM	error
`Unable to program flash`	Unable to program calibration table into BDU NOVRAM memory during calibration	Flash programming step fails at end of calibration procedure	critical
`Unable to read air flow sensor`	Error reading air flow sensor (Q2) serial EEPROM data	Initialize Flow Sensor function detects Q2 EEPROM read failure	error
`Unable to read O2 flow sensor`	Error reading oxygen flow sensor (Q1) serial EEPROM data	Initialize Flow Sensor function detects Q1 EEPROM read failure	error
`Unable to read the expiratory flow sensor`	Error reading exhalation flow sensor (Q3) serial EEPROM data	Initialize Flow Sensor function detects Q3 EEPROM read failure	error
`Unable to receive flash data`	GUI did not receive all calibration data from BDU within 10 seconds	Cal Info Duplication function timeout waiting for BDU data transmission	error
`Unexpected Interrupt`	Unexpected interrupt occurred	Unidentified interrupt	error
`Unknown NMI`	Unknown non-maskable interrupt	CPU interrupt during POST	error
`UT0002`	LCD controller PCB fault - bus error or access fault in VGA controller	VGA controller failure on upper or lower LCD PCB	error
`UT0002`	Assertion Failure - Background check (GUI)	Hardware-trap detection triggered; processor exception encountered	warning
`Uxxxxx`	Assertion failure (generic)	Background check GUI detects assertion	warning
`↑VE TOT`	Expiratory minute volume at or above set limit	Expiratory minute volume ≥ set limit	warning
`↓VE TOT`	Total minute volume below set limit for ≤20 s, >20 s, or >40 s	Total minute volume ≤ set limit for specified duration	warning
`↑VE TOT (lockable)`	Expiratory minute volume at or above set limit	Exhaled minute volume ≥ set limit	info
`↓VE TOT (Low Minute Volume Total)`	Total minute volume below set limit	Exhaled minute volume ≤ set limit for various durations	warning
`VN0129`	NMI: DRAM Parity Error	Memory parity error detected in GUI DRAM during operation	error
`VN0130`	NMI: Ethernet Parity Error	Ethernet controller parity error detected	error
`VN0132`	NMI: +5 V DC Overvoltage	+5V power rail exceeds safe operating voltage	error
`VN0136`	NMI: +12 V DC Overvoltage	+12V power rail exceeds safe operating voltage	error
`VN0144`	NMI: +12 V DC Undervoltage	+12V power rail drops below minimum operating voltage	error
`VOLUME NOT DELIVERED`	Ventilator unable to deliver target tidal volume on VC+ or VS breaths	Measured delivered volume below target; pressure reaches maximum limit	warning
`↑VTE`	Exhaled tidal volume at or above set limit	Exhaled tidal volume ≥ set limit	warning
`↑VTE (lockable)`	Exhaled tidal volume at or above set limit	Exhaled tidal volume ≥ set limit	info
`↓VTE MAND`	Exhaled mandatory tidal volume below set limit (2 of last 4 breaths)	Exhaled mandatory tidal volume ≤ set limit for 2 of last 4 mandatory breaths	warning
`↓VTE MAND (Low Tidal Volume Mandatory)`	Exhaled mandatory tidal volume below set limit	Exhaled mandatory VT ≤ set limit for multiple breaths	warning
`↓VTE SPONT`	Exhaled spontaneous tidal volume below set limit	Exhaled spontaneous tidal volume ≤ set limit	warning
`↓VTE SPONT (Low Tidal Volume Spontaneous)`	Exhaled spontaneous tidal volume below set limit	Exhaled spontaneous VT ≤ set limit; alarm updated when recalculated	warning
`↑VTI MAND`	Delivered inspiratory volume exceeds high limit (VC+ breath)	Delivered inspiratory volume ≥ high inspiratory volume limit (breath type = VC+)	warning
`↑VTI MAND (lockable)`	Delivered inspiratory volume exceeds high limit (VC+ breaths)	Delivered inspiratory volume ≥ high inspiratory volume limit (breath type VC+)	info
`↑VTI SPONT`	Delivered inspiratory volume exceeds high limit (TC or VS breath)	Delivered inspiratory volume ≥ high inspiratory volume limit (breath type = TC or VS)	warning
`↑VTI SPONT (lockable)`	Delivered inspiratory volume exceeds high limit (TC or VS breaths)	Delivered inspiratory volume ≥ high inspiratory volume limit (breath type TC or VS)	info
`XB0066`	Monitor alarms fail	Alarm monitoring system background check failure during GUI operation	critical
`XB0067`	Monitor apnea alarm fails	Apnea alarm monitoring background check failure	critical
`XB0068`	Monitor apnea int fails	Apnea interval monitoring system failure	critical
`XB0069`	Monitor high inspiratory pressure alarm test failure	High pressure alarm circuit malfunction	critical
`XB0069`	Monitor hip fails	High Inspiration Pressure (HIP) alarm monitoring failure	critical
`XB0070`	Monitor insp time fails	Inspiration time monitoring background check failure	critical
`XB0071`	Monitor no data	No monitoring data received during background check	critical
`XB0072`	Monitor data corrupted	Monitoring data integrity check failure; data corruption detected	critical
`XB0073`	Monitor O2 mixture fails	O2 mixture monitoring background check failure	critical
`XB0074`	Monitor breath time fails	Breath timing monitoring system failure	error
`XP0001`	Processor Initialization failed (GUI)	Fails during Phase 1 kernel POST	critical
`XP0002`	Integer Unit Test failed (GUI)	Fails during Phase 1 kernel POST	critical
`XP0003`	DRAM Refresh Timer Test failed (GUI)	Fails during Phase 1 kernel POST	critical
`XP0004`	Kernel DRAM Test failed (GUI)	Fails during Phase 1 kernel POST	critical
`XP0005`	Boot PROM Checksum Test failed (GUI)	Fails during Phase 1 kernel POST	critical
`XP0006`	Phase 2 Initialization Start failed (GUI)	Non-kernel POST portion fails to start	critical
`XP0007`	Addressing Mode Test failed (GUI)	Fails during Phase 1 kernel POST	critical
`XP0008`	Kernel NOVRAM Test failed (GUI)	Fails during Phase 1 kernel POST	critical
`XP0010`	Interrupt Controller Test	Interrupt handling circuit test failure during POST	critical
`XP0011`	Time of Day Clock Test failed (GUI, Major)	Fails during Phase 1 kernel POST	critical
`XP0012`	Timer Test failed (GUI)	Fails during Phase 1 kernel POST	critical
`XP0013`	Watchdog Timer Test	Watchdog timer did not respond as expected or trigger reset	error
`XP0015`	EEPROM Checksum Test failed (GUI)	Fails during Phase 1 kernel POST	critical
`XP0081`	Memory Management Unit Test failed (GUI)	MMU test failure	critical
`XP0082`	Bus Timer Test failed (GUI)	Bus activity monitoring failure	critical
`XP0083`	NMI Source Register Test	Non-maskable interrupt source register test failure	critical
`XP0084`	DRAM Memory Test failed (GUI)	DRAM data pattern verification fails	critical
`XP0084`	POST DRAM Test	POST phase DRAM memory test failure	critical
`XP0085`	Ethernet Self-Test Start failed (GUI)	Ethernet controller functionality error	critical
`XP0087`	Unexpected Reset Umpire Test	POST invoked three or more times in 24 operational hours due to unexpected resets	error
`XP0089`	Floating Point Unit Test failed (GUI)	FPU functionality test failure	critical
`XP0090`	DRAM Parity Circuit Test	DRAM parity checking circuit test failure during POST	critical
`XP0097`	SAAS Self-test Start failed	Alarm circuitry error or no audio feedback	critical
`XP0098`	SAAS Self-test End failed	Alarm circuitry error	critical
`XP0128`	Download OS Boot	Operating system download/initialization failure	critical
`XP0129`	Application OS Boot	Application operating system boot failure	critical
`XP0129`	Operating System Initialization failed (GUI)	OS fails to load	critical
`XP0130`	PB-MON Boot	Puritan Bennett monitoring system boot failure	critical
`XP0131`	Application Initialization failed (GUI)	Application software fails to load	critical
`XP0131`	Application Boot	Main application software boot failure	critical
`ZB0040`	Touch screen failed	Touch screen hardware not responding; no input detection	warning
`ZB0041`	Touch screen blocked	Touch screen input blocked; screen obstruction detected or input error	unknown
`ZB0042`	Touch screen resumed	Touch screen communication or functionality restored after previous failure	info
`ZB0046`	GUI Time of Day failed	Real-time clock (time of day) initialization or operation failure	warning
`ZB0047`	GUI NOVRAM checksum error	NOVRAM data integrity check failure; noncritical data corruption detected	warning
`ZB0052`	GUI key stuck	Keyboard key detected as continuously pressed or stuck	warning
`ZB0054`	GUI EEPROM checksum error	EEPROM data integrity check failure during boot or operation	warning
`ZB0055`	GUI SAAS communication failed	Self-Addressing Alarm System communication link failure	warning
`ZB0059`	Loss of BD communication	Communication lost between GUI and BD (Breathing Delivery) unit	critical
`ZB0061`	Resume BD communication	BD communication link re-established after previous loss	info
`ZB0063`	GUI SAAS Audio failed	SAAS audio output (alarm speaker) circuit failure	warning
`ZB0076`	Task Monitor	System task monitoring flag set; indicates potential system performance issue	info
`ZB0077`	GUI dropped a waveform packet	Waveform data packet lost in transmission from BD to GUI	info
`ZB0084`	Init Resume BD communication	BD communication reestablished during initialization or after recovery	info
`ZB0086`	Init Loss of BD communication	BD communication lost during initialization sequence	critical
`ZB0090`	Touch Screen blocked	Touch screen input blocked due to visible obstruction or contamination	unknown
`ZB0091`	Touch Screen resumed	Touch screen functionality restored; blocked error cleared	info
`ZC0xxx`	Communications error (BDU)	Communication error detected in BDU with BPS or external systems	warning
`ZC0xxx_BDU`	Communications error (BDU); battery power system condition	Communications error (BDU); BPS charging or status issue	warning
`ZC1xxx`	Communications error (GUI)	Additional GUI communication error variant; protocol or interface failure	warning
`ZC2000`	DCI parity error	Data Communication Interface parity check failure	warning
`ZC2001`	DCI input buffer overflow error	Communications error with GUI	warning
`ZC2002`	DCI command error; undefined command received	Communications error (GUI) undefined command received from host	warning
`ZC2003`	DCI unknown error	Unspecified communications error	warning
`ZP0008`	Kernel NOVRAM Test failure	Noncritical NOVRAM data failure	warning
`ZP0011`	Time of Day Clock Test failed (GUI, Minor)	Fails during Phase 1 kernel POST	warning
`ZP0085`	Ethernet Self-Test Start failure	Ethernet test failed during POST	error
`ZP0086`	Ethernet Self-test End (GUI)	Ethernet test completion	warning
`ZP0087`	Unexpected Reset Umpire Test	POST invoked after unexpected reset	warning
`ZP0088`	Phase 2 NOVRAM Test failed (GUI)	NOVRAM data out of valid range	warning

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ServiceForge knowledge base record. Field-unverified unless technicians confirmed it. A teaching summary of the record, not a service manual. Export 2026-10-14.