Infusion systems · Plum family

Hospira Plum XL: troubleshooting and error codes

The ServiceForge knowledge base holds 66 documented symptoms for the Hospira Plum XL, with 172 ranked causes, 54 diagnostic checks with test points and expected values, and 86 error codes. Each symptom below shows its causes and the first check; the rest is one connection away. Connect ServiceForge to your AI

Symptoms

Open Door Alarm Test failure

System fails to detect cassette door position or trigger alarm during PVT

Ranked causes

1. Cassette door open (common)
2. Cassette not properly seated (common)
3. Defective sensor PWA (rare)
4. Defective mechanism assembly (rare)
5. Defective MCU PWA or cable (rare)
6. Defective display PWA or cable (rare)

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

Open door alarm test fails

PVT open door alarm test failure when cassette door is not properly closed or seated

Ranked causes

1. Cassette door open (common)
2. Cassette not properly seated (common)
3. Defective sensor PWA or mechanism assembly (occasional)
4. Defective MCU PWA or ribbon cable (rare)
5. Defective display PWA or ribbon cable (rare)

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

Proximal occlusion test fails

PVT proximal occlusion detection test fails indicating sensor or cassette issue

Ranked causes

1. Closed proximal clamp (common)
2. Cassette not properly primed (common)
3. Defective cassette (occasional)
4. Dirty sensor pin (occasional)
5. Defective sensor PWA (rare)

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

Proximal Occlusion Test failure

System fails to detect proximal occlusion or trigger alarm during PVT

Ranked causes

1. Closed proximal clamp (common)
2. Cassette not properly primed (common)
3. Defective cassette (occasional)
4. Dirty sensor pin (occasional)
5. Defective sensor PWA (rare)

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

Battery legend test fails

PVT battery legend display test fails during performance verification

Ranked causes

1. Defective fuse (common)
2. Defective AC cordset (occasional)
3. Defective display PWA or ribbon cable (occasional)
4. Defective power supply PWA (occasional)

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

Battery Legend Test failure

Battery indicator or status does not display correctly during PVT

Ranked causes

1. Defective fuse (occasional)
2. Defective AC power cordset (occasional)
3. Defective display PWA or cable (rare)
4. Defective power supply PWA (rare)

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

Cassette door open or valve test failure caution

Cassette door is open, cassette improperly seated/loaded, or valve leak test detected excessive leakage

Ranked causes

1. Cassette door not closed or not fully seated (common)
2. Cassette priming incomplete or incorrect (common)
3. Defective administration set (occasional)
4. Fluid spillage around valve pins causing noise (rare)

First check

Turn knob to OFF CHARGE, open and close cassette door

2 more checks with pass and fail actions are in ServiceForge. Connect ServiceForge to your AI

Distal line occlusion detected patient safety

Infusion pump detects excessive pressure at distal sensor, indicating blockage downstream of pump in patient line

Ranked causes

1. Tubing kinked or bent (common)
2. IV site infiltration or occlusion (common)
3. Defective administration set (occasional)
4. Excessive pressure during valve test (rare)

First check

Inspect tubing for kinks along entire line

2 more checks with pass and fail actions are in ServiceForge. Connect ServiceForge to your AI

Distal occlusion test fails

PVT distal occlusion detection test fails indicating downstream sensor problem

Ranked causes

1. Cassette not properly primed (common)
2. Defective cassette (common)
3. Dirty sensor pin (occasional)
4. Defective sensor PWA (rare)

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

Distal Occlusion Test failure

System fails to detect distal occlusion or trigger alarm during PVT

Ranked causes

1. Cassette not properly primed (common)
2. Defective cassette (occasional)
3. Dirty sensor pin (occasional)
4. Defective sensor PWA (rare)

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

Empty container/air-in-line alarm test fails

PVT empty container or air detection test fails indicating bubble sensor issue

Ranked causes

1. Defective special cassette (common)
2. Dirty bubble sensors (common)
3. Defective bubble sensor PWA (occasional)
4. Defective sensor PWA (occasional)

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

Empty Container/Air-in-Line Alarm Test failure

System fails to detect empty container or air in line during PVT

Ranked causes

1. Defective special cassette (occasional)
2. Dirty bubble sensors (occasional)
3. Defective bubble sensor PWA (rare)
4. Defective sensor PWA (rare)

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

Free flow test fails

PVT free flow test fails indicating obstruction or cassette problems

Ranked causes

1. Cassette not properly seated (common)
2. Defective cassette (common)
3. Defective or dirty valve pins (occasional)
4. Defective mechanism assembly (occasional)

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

Proximal line occlusion detected patient safety

High pressure upstream indicates blockage in drug container line or tubing before pump

Ranked causes

1. Tubing clamp left closed (common)
2. Tubing kinked or bent (common)
3. Occluded or collapsed tubing (occasional)
4. Defective administration set or pressure circuit (occasional)

First check

Verify tubing clamp is open

2 more checks with pass and fail actions are in ServiceForge. Connect ServiceForge to your AI

ADC reference voltage out of tolerance caution

ADC reference voltage (+2.5VDC or +5VDC) measured outside specification range

Ranked causes

1. +2.5VDC reference voltage missing or out of spec (common)
2. +3.75VDC reference voltage missing or out of spec (common)
3. ADC converter failure (occasional)

First check

Replace fuse on power supply PWA if required

Air in line alarm caution

Air bolus or stream detected in cassette or at distal sensor

Ranked causes

1. Air in proximal cassette (common)
2. Distal air bolus detected (occasional)
3. Empty container (common)

First check

Observe air location and volume

Expected: No visible air in line

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

Alarm loudness test fails

PVT alarm loudness test fails or buzzer does not sound at proper level

Ranked causes

1. Corrosive buildup on buzzer (common)
2. Defective MCU PWA (occasional)
3. Defective power supply PWA (occasional)

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

Alarm Loudness Test failure

Alarm buzzer does not produce sound or has incorrect volume during PVT

Ranked causes

1. Corrosive buildup on buzzer bottom surface (occasional)
2. Defective MCU PWA (rare)
3. Defective power supply PWA (rare)

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

Audio buzzer signal out of range caution

Audio buzzer signal measurement outside normal operating range, buzzer may not function or sound incorrect

Ranked causes

1. Audio buzzer hardware failure (occasional)
2. MCU ADC malfunction (occasional)
3. ADC reference voltage out of specification (occasional)

First check

Measure audio buzzer signal output

Expected: Within normal operating range

Battery charger current test fails caution

Optional battery charger current test fails during PVT

Ranked causes

1. Blown fuse (common)
2. Defective AC cordset (occasional)
3. Defective power supply PWA (occasional)

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

Battery Charger Current Test failure

Battery charger fails to supply current during optional PVT test

Ranked causes

1. Blown fuse (common)
2. Defective AC power cordset (occasional)
3. Defective power supply PWA (rare)

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

Cassette or valve leak test failure caution

Input/output valve or cassette door issue; leak detected during self-test

Ranked causes

1. Cassette improperly loaded or primed (common)
2. Defective administration set (occasional)
3. Fluid spillage around valve pins (occasional)

First check

Verify cassette seating and priming

Expected: Cassette fully seated and primed

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

DataPort connection/ground continuity test fails

Optional DataPort connection and ground continuity test failure

Ranked causes

1. Insufficient ground connection (common)
2. Defective DataPort/MCU cable (occasional)
3. Cable not properly seated (occasional)

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

DataPort Connection/Ground Continuity Test failure

DataPort connection or ground continuity fails during optional PVT test

Ranked causes

1. Insufficient ground connection from DataPort to ground screw (common)
2. Defective DataPort/MCU cable assembly (occasional)
3. DataPort/MCU cable not properly seated on MCU PWA (occasional)

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

Delivery accuracy test fails

PVT delivery accuracy test fails indicating flow measurement or pump problem

Ranked causes

1. Set not properly primed (common)
2. Damaged or faulty set (common)
3. Defective mechanism assembly (occasional)

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

Delivery Accuracy Test failure

Infusion system fails to deliver fluid at correct rate during PVT

Ranked causes

1. Set not properly primed (common)
2. Damaged or faulty set (occasional)
3. Defective mechanism assembly (rare)

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

Distal occlusion alarm caution

Distal pressure exceeds threshold; tubing may be kinked, IV site compromised, or administration set defective

Ranked causes

1. Kinked tubing (common)
2. IV site compromised (common)
3. Defective administration set (occasional)

First check

Inspect tubing for kinks

Expected: No kinks present

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

Electrical safety test fails high voltage

PVT electrical safety test fails indicating ground connection or power supply issue

Ranked causes

1. Insufficient ground connection (common)
2. Defective AC cordset (occasional)
3. Defective power supply PWA (occasional)

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

Electrical Safety Test failure high voltage

Ground connection or electrical safety measures fail during PVT

Ranked causes

1. Insufficient ground connection (common)
2. Defective AC power cordset (occasional)
3. Defective power supply PWA (rare)

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

Free Flow Test failure

Fluid does not flow freely through the cassette during PVT

Ranked causes

1. Cassette not properly seated (common)
2. Defective cassette (occasional)
3. Defective or dirty valve pins (occasional)

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

Input/output motor position error during resync patient safety

I/O motor position flag stuck high or signal continuous low during re-synchronization

Ranked causes

1. Position sensor failure (common)
2. I/O motor not moving or stuck (occasional)
3. Enable circuit failure (occasional)

First check

Check connection at J8 on MCU PWA for looseness or damage

No communication to host computer caution

Device cannot communicate with host computer; UART or MCU hardware failure

Ranked causes

1. UART loop-back test failure (rare)
2. Excessive UART interrupts (rare)
3. UART receiver buffer overflow (rare)

First check

Verify host connection

Expected: Device communicating with host

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

Plunger motor position error during resync patient safety

Plunger motor position flag stuck high or signal continuous low during re-synchronization

Ranked causes

1. Position sensor failure (common)
2. Plunger motor not moving or stuck (occasional)
3. Enable circuit failure (occasional)

First check

Check connection at J7 on MCU PWA for looseness or damage

Proximal occlusion alarm caution

Pressure buildup on proximal side due to tubing kink, clamp, blockage, or defective circuit

Ranked causes

1. Clamp is closed (common)
2. Tubing kinked (common)
3. Occluded tubing or defective circuit (occasional)

First check

Verify clamp position

Expected: Clamp open

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

Valve pin position detection failure patient safety

Primary or secondary valve pin not detected as moving or valve pin not present during self-test

Ranked causes

1. Pin detect circuitry failure (occasional)
2. Valve pin missing or not present (occasional)
3. Valve pin stuck or mechanically jammed (occasional)

First check

Inspect valve pin physically and verify pin detect sensor output

Air detected in line - proximal patient safety

Proximal air-in-line alarm during backpriming or intake strokes

Ranked causes

1. Air in cassette during backpriming initialization (common)
2. Container run dry during intake strokes (occasional)

First check

Perform backpriming procedure to expel air from cassette

1 more check with pass and fail actions are in ServiceForge. Connect ServiceForge to your AI

Air sensor self-test or signal failure patient safety

Air sensor self-test fails or sensor signal level out of specification when sensors disabled

Ranked causes

1. Air sensor hardware failure (occasional)
2. Air sensor circuitry or conditioning circuit failure (occasional)

First check

Inspect proximal and distal air sensor connections and signal levels

Calibration data in EEPROM checksum failure caution

EEPROM checksum validation of calibration data fails on power-up or operation

Ranked causes

1. EEPROM chip internal failure (rare)
2. EEPROM decode circuitry failure (rare)

First check

System self-test detected EEPROM checksum error

Cassette door open

Cassette door is open or cassette not seated properly

Ranked causes

1. Door is open (common)
2. Cassette not seated properly (occasional)

First check

Verify door position

Expected: Door closed and latched

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

Control knob between valid states

Control knob stuck between positions for 5 minutes or defective assembly

Ranked causes

1. Knob in invalid position (occasional)
2. Defective control knob assembly (occasional)

First check

Verify knob moves freely to valid positions

Expected: Knob clicks into RUN, OFF/CHARGE, or HOLD/RESET

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

Control knob circuitry failure

Control knob signal detected when disabled, illegal signal pattern detected, or reed switch mismatch with knob position

Ranked causes

1. Control knob switch circuitry failure (occasional)
2. Reed switch misalignment or failure (occasional)

First check

Verify control knob moves smoothly and generates expected signals

Control panel key stuck in ON position

Front panel key remains continuously pressed or switch stuck closed; key does not respond to user input

Ranked causes

1. Physical key mechanism stuck or jammed (common)
2. Display PWA switch shorted or mechanically stuck (occasional)

First check

Attempt to press and release key multiple times

Keypad and control knob test fails

PVT keypad and control knob test fails during performance verification

Ranked causes

1. Defective display PWA or ribbon cable (common)
2. Defective control knob (occasional)

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

Keypad and Control Knob Test failure

Keypad or control knob does not respond during performance verification

Ranked causes

1. Defective display PWA or cable (occasional)
2. Defective control knob (occasional)

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

Low or discharged battery caution

Battery charge is depleted; device cannot operate on battery power alone

Ranked causes

1. Battery charge insufficient (common)
2. Battery fully discharged (occasional)

First check

Connect device to AC power supply

1 more check with pass and fail actions are in ServiceForge. Connect ServiceForge to your AI

Motor voltage drop excessive when energized caution

Motor supply voltage drops too much when motor is commanded to operate, indicating power supply limitation or motor current issue

Ranked causes

1. Power supply PWA unable to supply required current (occasional)
2. Motor drawing excessive current (shorted winding or mechanical jam) (occasional)

First check

Measure motor supply voltage under motor load

Expected: Voltage remains stable with minimal droop

Power supply signal mismatch or out of tolerance high voltage

Power supply PWA signals (HKDC, DHKDC, VMOT) do not match or measured out of tolerance

Ranked causes

1. Power supply PWA failure or component failure (occasional)
2. Failure of conditioning circuit on MCU PWA (occasional)

First check

Measure power supply output signals with AC power applied

Expected: HKDC/DHKDC matched; VMOT within spec

Primary/secondary motor position error during resync patient safety

Primary/secondary motor position flag stuck high or signal continuous low during re-synchronization

Ranked causes

1. Position sensor failure (common)
2. Primary/secondary motor not moving or stuck (occasional)

First check

Check connection at J9 on MCU PWA for looseness or damage

Self test fails

Performance verification test fails during self-test phase

Ranked causes

1. Cassette not properly installed (common)
2. Defective MCU PWA (occasional)

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

Self Test failure

Cassette fails to properly install or pass self test during PVT

Ranked causes

1. Cassette not properly installed (occasional)
2. Defective MCU PWA (rare)

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

Turn to run alarm

Control knob not in a valid running position or no button pressed for 5 minutes

Ranked causes

1. Control knob in wrong position (common)
2. No input for 5 minutes (occasional)

First check

Verify knob position

Expected: Knob in RUN, OFF/CHARGE, or HOLD/RESET

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

Valve motor malfunction patient safety

Valve motor operates at incorrect time or motor synchronization fails

Ranked causes

1. Position sensor failure (occasional)
2. Motor drive circuit failure (occasional)

First check

Verify valve motor position sensor operation

Air detected in line - distal patient safety

Distal air-in-line alarm indicating air bolus in delivery line at distal sensor

Ranked causes

1. Air in cassette during initialization or priming (common)

Check settings alarm

Rate and VTBI settings not correct or not matching

Ranked causes

1. Incorrect rate or VTBI setting (common)

First check

Verify rate and VTBI settings

Expected: Settings match prescription

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Discharged battery alarm

Battery fully discharged; system will shut down in 1 minute

Ranked causes

1. Battery depleted (common)

First check

Verify AC power or swap battery immediately

Expected: Power restored within 1 minute

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Fuse replacement required high voltage

Fuse needs to be replaced on the power supply PWA in the rear enclosure assembly

Ranked causes

1. Fuse open or blown (unknown)

First check

Verify fuse rating matches power supply PWA marking

Test point: Power supply PWA fuse location
Expected: 0.5A, 250V, Slo-Blo, 5 x 20 mm

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

Internal software self-test failure caution

One of the MCU internal software self-test routines detected a failure during power-up or operation

Ranked causes

1. MCU internal hardware or software failure (rare)

First check

System self-test detected internal software test failure (error codes 99-1 through 99-6)

Internal timer out of tolerance caution

Internal MCU timer frequency or timing reference out of specification

Ranked causes

1. MCU PWA internal malfunction or component failure (rare)

First check

System self-test detected timer tolerance error

Lock violation alarm

Control knob position changed while system in LOCKED mode

Ranked causes

1. Knob moved while locked (common)

First check

Verify LOCK button status

Expected: System unlocked and accessible

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

Low battery alarm

Battery charge low; system may lose function without AC power

Ranked causes

1. Low battery charge (common)

First check

Verify AC power connection

Expected: AC power connected and charging

1 corrective action and part numbers are in ServiceForge. Connect ServiceForge to your AI

More symptoms

Motor phase loss - input/output
Motor phase loss - plunger
Motor phase loss - primary/secondary
UART communication failure during operation
Unit does not power on
VTBI complete alarm

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

Error codes

Code	Meaning	Trigger	Severity
`01-1`	OCCLUSION	Distal pressure above 10 psi for five seconds	warning
`01-2`	Distal occlusion alarm	Distal pressure above 10 psi for two plunger strokes	warning
`01-3`	Distal occlusion alarm	Distal pressure above 13 psi	warning
`01-4`	Distal occlusion alarm	Excessive distal pressure during valve leak test	warning
`03-1`	Proximal occlusion alarm	Clamp closed, kinked, occluded tubing, or defective set; defective pressure circuit	warning
`03-2`	Proximal occlusion on secondary during backpriming	Clamp closed, kinked, occluded tubing, or defective set	warning
`06-1`	Air in line backpriming alarm	1000 µL of air entered cassette since initialization	warning
`07-1`	Distal air-in-line alarm	100 µL bolus of air detected at distal sensor	warning
`07-2`	Distal air-in-line alarm	260 µL of air detected in last 2.6 mL delivered	warning
`08-1`	Air in line backpriming alarm	500 µL air entered cassette in last two intake strokes	warning
`10-1`	Check alarm settings	Rate and VTBI settings not correct	warning
`11-1`	TURN TO RUN	Rotary control knob not in OFF/CHARGE or RUN position, or no button pressed for five minutes	info
`12-1`	VTBI COMPLETE	Primary channel has delivered programmed volume	info
`12-2`	VTBI COMPLETE	Secondary channel has delivered programmed volume	info
`13-1`	Cassette/door or input-output valve leak test failure	Door open or valve test failure	error
`13-1`	CASSETTE DOOR/CASSETTE	Input/output valve leak test failure or cassette door issue on XL model	warning
`13-2`	Cassette/door or primary-secondary valve leak test failure	Door open or valve test failure	error
`13-3`	Cassette/door or valve leak test failure from noise	Fluid spillage around valve pins causes signal noise	error
`14-1`	LOCKED	Control knob position changed while in LOCKED mode	info
`14-1`	Lock violation alarm	Knob position changed while in LOCKED mode	warning
`15-1`	No computer comms (UART loop-back failure)	UART loop-back test during power-up failed	error
`15-1`	UART test failure	UART loop-back test failed during power-up	error
`15-2`	No computer comms (frequent UART interrupts)	Excessively frequent UART interrupts	error
`15-3`	No computer comms (UART buffer overflow)	UART receiver buffer overflowed	error
`16-1`	Knob between valid states for 5 minutes	Knob not in OFF CHARGE or RUN for 5 min	error
`16-1`	TURN TO RUN	Control knob between valid positions for five minutes	warning
`17-1`	Low battery alarm	Low battery detected	warning
`17-2`	Low battery re-alarm after 15 min	Low battery condition persists	warning
`18-1`	LOW BATTERY Discharged	Battery fully discharged	error
`18-1`	Discharged battery alarm	Battery fully discharged	critical
`18-2`	System shutdown after discharged battery	Battery fully discharged	critical
`18-2`	Display blank; battery discharged	System shutdown one minute after discharged battery alarm	critical
`19-1`	DOOR	Cassette door open or cassette not seated properly	warning
`20-1`	Stack overflow	MCU RAM error	critical
`21-1`	Critical data checksum failure at startup	Critical data checksum error during power-up	error
`21-2`	Critical data checksum failure during operation	Critical data checksum error while system running	error
`21-3`	Checksum of operational parameters failure at startup	Operational parameters checksum error during power-up	error
`21-4`	Checksum of operational parameters failure during operation	Operational parameters checksum error during runtime	error
`29-1`	ROM checksum failure at startup	ROM checksum error during power-up	error
`29-2`	ROM checksum failure during operation	ROM checksum error during runtime	error
`29-3`	ROM checksum test not being performed	ROM checksum test not running	error
`34-1`	EEPROM read/write test failure	EEPROM chip test failed	error
`35-1`	Critical RAM values found incorrect	RAM integrity check failed	error
`41-1`	LCD driver chip test failure	LCD driver self-test failed	error
`44-1`	Audio BUZZER signal out of range	Buzzer or audio circuit failure detected	error
`44-2`	ADC malfunction or reference voltage incorrect	ADC on MCU not functioning or reference voltage wrong	error
`44-2`	Audio buzzer signal out of range	Audio buzzer signal measurement out of spec	error
`45-1`	[PRI/SEC] key stuck in ON position	Front panel key physically stuck or switch S1 shorted	error
`45-2`	[UP ARROW] key stuck in ON position	Front panel key physically stuck or switch S3 shorted	error
`45-3`	[DOWN ARROW] key stuck in ON position	Front panel key physically stuck or switch S2 shorted	error
`45-4`	[TITRATE] key stuck in ON position	Front panel key physically stuck or switch S4 shorted	error
`45-5`	[BACKPRIME] key stuck in ON position	Front panel key physically stuck or switch S5 shorted	error
`45-6`	[SILENCE] key stuck in ON position	Front panel key physically stuck or switch S6 shorted	error
`59-1`	Valve motor moving at wrong time	Valve motor operates when not expected	error
`60-1`	Plunger motor position flag stuck high during re-synchronization	Position sensor continuously high during sync sequence	error
`60-2`	Plunger motor position signal continuous low during re-synchronization	Position sensor signal stuck low during sync	error
`61-1`	Input/output motor position flag continuous high during re-synchronization	IO motor position sensor stuck high during sync	error
`61-2`	Input/output motor position signal continuous low during re-synchronization	IO motor position sensor stuck low during sync	error
`62-1`	Primary/secondary motor position flag continuous high during re-synchronization	Prim/sec motor position sensor stuck high during sync	error
`62-2`	Primary/secondary motor position signal continuous low during re-synchronization	Prim/sec motor position sensor stuck low during sync	error
`63-1`	Plunger motor phase loss	Plunger motor lacks sufficient torque	error
`64-1`	Input/output motor phase loss	Input/output motor lacks sufficient torque	error
`65-1`	Primary/secondary motor phase loss	Primary/secondary motor lacks sufficient torque	error
`71-1`	Internal timers out of tolerance	MCU internal timer malfunction detected	error
`73-1`	+2.5-VDC ADC reference voltage out of tolerance	ADC reference voltage exceeds tolerance	error
`73-2`	+5-VDC ADC reference voltage out of tolerance	ADC +5V reference voltage exceeds tolerance	error
`74-1`	Air sensor self-test failure; signal when sensors disabled	Air sensor signal detected when disabled or self-test detects failure	warning
`74-4`	Proximal air sensor signal too high	Proximal air sensor output exceeds threshold	error
`74-5`	Distal air sensor signal too high	Distal air sensor output exceeds threshold	error
`81-1`	Power supply PWA signals HKDC and DHKDC do not match	Power supply heartbeat signals mismatch	error
`81-2`	Power supply PWA signal HKDC out of tolerance	HKDC signal magnitude exceeds tolerance	error
`81-3`	Power supply PWA signal VMOT out of tolerance when AC power applied	Motor voltage signal out of range with AC power	error
`81-4`	Motor voltage drops too much when motor energized	Excessive voltage drop during motor operation	error
`90-1`	Calibration data in EEPROM checksum failure	EEPROM calibration data checksum error	error
`94-1`	Control knob signal seen when disabled	Control knob generates signal during disabled state	error
`94-2`	Illegal control knob signal seen	Invalid control knob signal detected	error
`94-4`	Reed switch does not match control knob signal	Reed switch output does not correspond to knob position	error
`95-1`	Primary valve pin not moving	Primary valve pin position not detected	error
`95-2`	Secondary valve pin not moving	Secondary valve pin position not detected	error
`96-1`	UART test failure during operation	UART self-test failed while system running	error
`99-1`	Failure of internal software self-test (99-1 through 99-6)	Software self-test routine failed	error
`99-2`	Internal software self-test failure (code 2)	Internal software self-test routine detects failure	critical
`99-3`	Internal software self-test failure (code 3)	Internal software self-test routine detects failure	critical
`99-4`	Internal software self-test failure (code 4)	Internal software self-test routine detects failure	critical
`99-5`	Internal software self-test failure (code 5)	Internal software self-test routine detects failure	critical
`99-6`	Internal software self-test failure (code 6)	Internal software self-test routine detects failure	critical

Likely causes and actions for each code are in ServiceForge. Connect ServiceForge to your AI

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0 fixes logged by technicians through their AI, with outcomes, for this model.

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