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Patient monitors · Propaq family

Welch Allyn Propaq CS: troubleshooting and error codes

The ServiceForge knowledge base holds 53 documented symptoms for the Welch Allyn Propaq CS, with 61 ranked causes, 116 diagnostic checks with test points and expected values, and 25 error codes. Each symptom below shows its causes and the first check; the rest is one connection away. Connect ServiceForge to your AI

Symptoms

Sidestream CO2 assemblies require replacement caution

SSP Board, Stick Board, or Extender Board replacement in Expansion Module for Sidestream CO2 option

Ranked causes

  1. 1. Worn or failed Sidestream CO2 components (unknown)
  2. 2. SSP or Stick Board failure (unknown)
  3. 3. Board reassembly required (common)
First check

Visually inspect Extender Board for damage or corrosion

Test point
Extender Board, P6 connector
Expected
No visible damage, clean connections

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

Air leak in NIBP cuff fitting patient safety

Air system leakage from NIBP cuff connection causing inaccurate or failed measurements

Ranked causes

  1. 1. Worn or damaged O-ring gasket in cuff fitting (common)
  2. 2. Pinched or cracked cuff hose (occasional)
First check

Visual inspection of O-ring gasket for wear or damage

Test point
Cuff fitting O-ring
Expected
O-ring intact and properly seated

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

Analog board removal and reinstallation high voltage

Procedure to remove analog board from front chassis for service or replacement

Ranked causes

  1. 1. Scheduled replacement or repair of analog board (common)
  2. 2. Reinstall analog board (common)
First check

Expose power connector on control board

Test point
4-wire cable in middle of control board
Expected
Power connector visible and accessible

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

Calibration: Functional verification of Propaq CS monitor patient safety

Comprehensive functional verification procedure to confirm proper operation of Propaq CS monitor and options without disassembly. Supports routine preventive maintenance. Service Menus access internal software routines for testing NIBP, display, invasive pressure, and printer channels.

Ranked causes

  1. 1. Post-calibration verification required (common)
  2. 2. Post-circuit board replacement verification (occasional)
First check

Verify power-up self-test completion

Test point
Monitor startup
Expected
All software and hardware tests successful, monitor ready for use

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

ECG/RESP waveform not displayed correctly patient safety

Monitor fails to display normal sinus rhythm ECG or respiration waveform with correct heart rate and respiration rate

Ranked causes

  1. 1. ECG lead disconnected or improperly connected (common)
  2. 2. Patient simulator not configured correctly (occasional)
First check

Patient simulator configuration

Test point
Patient simulator display settings
Expected
ECG waveform normal sinus rhythm, rate 80 bpm, size 1 mV, Resp Lead I, baseline 1 KΩ, rate 40 br/m, amplitude 1.0Ω

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

Monitor battery does not charge

The monitor battery fails to charge when AC power adapter is connected and functioning. Battery does not hold adequate charge.

Ranked causes

  1. 1. Fuse F1 open protecting dc input (common)
  2. 2. Battery pack no longer holds adequate charge (common)
First check

Verify AC power adapter is functioning properly

Test point
AC power adapter input
Expected
AC adapter functional and supplying power

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

NIBP pump leakage exceeds specification

After 4 minutes of pump test with neonatal cuff, displayed leakage exceeds 50 mm Hg specification

Ranked causes

  1. 1. Air leak in external hoses or fittings (common)
  2. 2. Internal air leak in pump or transducer (occasional)
First check

After 4 minutes of pump inflation, measure displayed leakage

Test point
Leakage display in PUMP TEST mode
Expected
<50 mm Hg, Less than specification

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

Battery drained causing settings loss

Program fault with settings lost and time/day reset at startup

Ranked causes

  1. 1. Battery depleted or dead (common)

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

Battery not charging and green LED indicator not illuminating

The green LED charging indicator on the monitor's right side panel does not illuminate and the monitor battery does not charge when AC power adapter is connected and functioning properly.

Ranked causes

  1. 1. Fuse F1 open or failed (common)
First check

Inspect fuse F1 for continuity or visible damage

Test point
Fuse F1 at dc input connector
Expected
Fuse intact with no visible damage; continuity present

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

Cable continuity compromised caution

Cable fails continuity testing on one or more pins; signal not transmitted or intermittent

Ranked causes

  1. 1. Cable conductor break or corrosion (occasional)
First check

Check cable continuity on all pins using DMM

Test point
All cable pins
Expected
Continuity on all pins; < 1 ohm resistance

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

Cable suspected faulty

Cable continuity failure on one or more pins; requires replacement

Ranked causes

  1. 1. Cable continuity failure (unknown)
First check

Check cable continuity on all pins

Test point
All cable pins
Expected
Continuity present on all pins

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

Cabling and connector routing during side panel installation

Bundle of cabling with bead must be routed correctly so connectors extend out of Rear Chassis properly

Ranked causes

  1. 1. Improper cable routing during installation (occasional)
First check

Verify cabling is routed under temperature connector housing

Test point
Cable bundle and temperature connector housing
Expected
Bundle routed under temperature connector housing with connectors extending from bottom of Chassis

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

Calibration: Invasive Blood Pressure channel P2 patient safety

Verify or adjust second IBP channel P2 to read 200 ±2 mmHg using blood pressure simulator

Ranked causes

  1. 1. P2 channel requires verification or adjustment (occasional)
First check

Verify P2 displays 200 ±2 mmHg after zeroing and setting simulator

Test point
P2 display on monitor screen
Expected
200 ±2 mmHg, ±2 mmHg

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

Calibration: Monitoring parameter circuits patient safety

Monitor does not pass functional verification; calibration or repair required

Ranked causes

  1. 1. Monitoring parameter circuits out of calibration (unknown)

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

Calibration: MSP Board (MCO2) barometric pressure

Monitor displays barometric pressure that requires calibration adjustment to meet specification limits.

Ranked causes

  1. 1. Barometric pressure reading outside calibration limits (unknown)
First check

Observe displayed barometric pressure on monitor CO2 TEST MAIN TEST screen

Test point
Monitor display
Expected
Within 3 mmHg of local barometric pressure

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

Calibration: MSP Board electromagnetic interference emissions

RP2 null adjustment for electromagnetic interference emissions control.

Ranked causes

  1. 1. Electromagnetic interference emissions calibration required (unknown)
First check

Connect oscilloscope probe to TP50 on MSP Board

Test point
TP50
Expected
Probe ground tip left open, 1X probe configuration
Tools
Oscilloscope with 1X probe

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

Calibration: Realtime ECG Output

ECG signal output level adjustment on Propaq CS monitor to ensure correct waveform amplitude.

Ranked causes

  1. 1. ECG output requires calibration adjustment (unknown)
First check

Set simulator parameters

Test point
Simulator output
Expected
80 bpm, normal sinus rhythm

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

Calibration: Recharger supply adjustments high voltage

Adjustment of voltage regulators RP5, RP3, and RP1 on Recharger Board to maintain proper battery charging voltage and overvoltage protection limits across input voltage range.

Ranked causes

  1. 1. Recharger Board voltage regulation requires calibration (common)
First check

Verify monitor power and disconnect connectors

Test point
Power switch, P12, P8
Expected
Monitor off, P12 and P8 disconnected

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

Calibration: Recharger Supply Output Voltage high voltage

Procedure to verify and adjust recharger board output voltage to specification using test load and variable DC power supply.

Ranked causes

  1. 1. Recharger supply requires calibration adjustment (unknown)
First check

Monitor power switch

Test point
Power switch
Expected
Off

9 more checks with pass and fail actions, 8 corrective actions, and part numbers are in ServiceForge. Connect ServiceForge to your AI

CO2 sensor calibration failure

Sensor failure with calibration error detected

Ranked causes

  1. 1. CO2 sensor failure (common)

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

CO2 sensor EEPROM failure

Sensor EEPROM failure detected, CO2 channel disabled

Ranked causes

  1. 1. Sensor EEPROM checksum error or failure (common)

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

CO2 sensor heater failure

Sensor temperature control hardware failure detected

Ranked causes

  1. 1. Sensor heater failure or MSP board malfunction (common)

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

CO2 sensor motor drive failure

Mainstream sensor motor drive hardware failure, channel disabled

Ranked causes

  1. 1. Sensor motor drive hardware failed (common)

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

CO2 waveform absent

No CO2 waveform signal displayed

Ranked causes

  1. 1. Cuvette contaminated or light source faulty (common)

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

CO2 waveform degraded

Degraded or absent CO2 waveform signal

Ranked causes

  1. 1. Cuvette contaminated or light source faulty (common)

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

Equipment alert not triggered on ECG lead disconnection patient safety

Monitor fails to display ECG FAULT message when a single ECG lead is disconnected

Ranked causes

  1. 1. ECG lead fault detection circuit not functioning (rare)
First check

Single ECG lead disconnection alert

Test point
Monitor display message area and ALARM(S) OFF indicator light
Expected
EQUIPMENT ALERT / ECG FAULT message displayed indicating removed lead; ALARM(S) OFF light flashes; for software 3.6x+ ECG FAULT at top; for other versions ECG FAULT and RESP FAULT alternate

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

Expansion Module rear panel reassembly caution

Procedure to close and secure Expansion Module after repair or component replacement

Ranked causes

  1. 1. Module reassembly after service (unknown)
First check

Verify spacers present before tightening

Test point
Expansion Module Chassis mounting points
Expected
All spacers in place; five upper spacers omitted when SpO2 module present

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

Expansion Module rear panel removal caution

Procedure to disassemble Expansion Module for component access and repair

Ranked causes

  1. 1. Routine maintenance or component replacement required (unknown)

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

Expansion module side panel replacement needed caution

Patient connector or speaker side panel deteriorated or damaged; requires removal and replacement

Ranked causes

  1. 1. Side panel physical damage or wear (rare)

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

Functional verification after calibration or board replacement

Need to confirm proper operation of Propaq CS monitor and options after calibration or circuit board replacement. Software and hardware self-tests check programming integrity, then hardware.

Ranked causes

  1. 1. Calibration performed or circuit board replaced (common)

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

Fuse F1 open due to RP3 misadjustment caution

Fuse F1 on the right side panel opens as a result of incorrect RP3 adjustment during recharger supply calibration.

Ranked causes

  1. 1. RP3 overvoltage limit misadjusted (occasional)

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

Green LED charging indicator does not illuminate

The green LED on the monitor's right side panel does not light up when AC power adapter is connected and functioning properly.

Ranked causes

  1. 1. Fuse F1 open or defective (common)
First check

Verify fuse F1 integrity

Test point
Fuse F1 on Recharger Board at dc input connector
Expected
Fuse intact and continuous (not open)

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

Monitor does not power on, battery charging indicator lights caution

Unit fails to turn on when AC power adapter connected, but BATTERY CHARGING indicator illuminates

Ranked causes

  1. 1. Recharger Board fuse F2 open (common)
First check

Verify fuse F2 continuity or visual inspection for open

Test point
Fuse F2
Expected
Continuity or intact filament
Tools
Multimeter or visual inspection

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

MSP and SpO2 Board replacement caution

Replacement of MSP Board and SpO2 Board in main unit

Ranked causes

  1. 1. Failed or degraded MSP or SpO2 Board (unknown)
First check

Disconnect speaker cable from MSP Board

Test point
Speaker cable connector on MSP Board
Expected
Cable fully disconnected

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

MSP/SpO2 Boards require replacement caution

Expansion Module with CO2 option needs board replacement procedure

Ranked causes

  1. 1. MSP/SpO2 Board failure or malfunction (unknown)
First check

Open Expansion Module

Test point
Expansion Module housing
Expected
Module opened

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

NIBP cuff hose air leak patient safety

Air system integrity compromised; non-invasive blood pressure measurements inaccurate or not obtainable

Ranked causes

  1. 1. O-ring gasket worn or degraded in threaded cuff hose fitting (common)
First check

Inspect cuff hose fittings for air leaks under pressure

Test point
Cuff hose threaded fitting connection
Expected
No visible air leaks; constant pressure maintained

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

NIBP system fault

NIBP system disabled, single fault encountered

Ranked causes

  1. 1. NIBP system malfunction (common)

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

Printer not functioning

Printer paper not feeding or printing; mechanical jam or failure to engage with media

Ranked causes

  1. 1. Printer Assembly mechanical failure or jam (unknown)

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

PROM replacement caution

PROM requires removal and installation using special tool to prevent socket damage and static discharge

Ranked causes

  1. 1. PROM failure or upgrade required (unknown)

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

PROM replacement required caution

Software PROM needs replacement due to corruption, obsolescence, or malfunction

Ranked causes

  1. 1. PROM damaged by static discharge or wear (occasional)
First check

Verify equipment is at static-protected workstation

Test point
Work environment
Expected
Static-protected work area with grounding

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

PROM suspected faulty or needs replacement caution

Need to replace PROM chips on Digital Board; procedure requires special handling to prevent damage.

Ranked causes

  1. 1. PROM failure or software update required (unknown)

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

Radio card replacement required caution

Symbol Radio PCMCIA card or antenna assembly needs replacement for wireless functionality restoration

Ranked causes

  1. 1. Radio card malfunction or incompatibility (occasional)
First check

Check expansion module label for radio frequency marking

Test point
Expansion module label
Expected
Presence of specific frequency symbol indicates 5 GHz requirement

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

Reinstall Digital Board or Display patient safety

Reassembly procedure with specific torque specifications and cable installation order to ensure proper component seating and electrical connectivity.

Ranked causes

  1. 1. Reinstallation following replacement (unknown)

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

Replace Digital Board or Display patient safety

Digital Board contains monitor-specific configuration programming; Display is beneath Digital Board. Both require careful disassembly and reassembly procedures.

Ranked causes

  1. 1. Digital Board or Display replacement required (unknown)

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

Replace SpO2 Boards caution

Procedure to replace two SpO2 Boards in SpO2 module or Expansion Module without CO2 option

Ranked causes

  1. 1. SpO2 Board requires replacement (unknown)
First check

Open SpO2 Module or Expansion Module

Test point
Module housing
Expected
Module opened per procedure

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

Replace Symbol Radio PCMCIA Card

Replacement of wireless Acuity option radio card assembly on Digital Board for Propaq CS monitor

Ranked causes

  1. 1. Symbol Radio PCMCIA Card failure or upgrade required (unknown)

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

Required test equipment for functional verification

Complete list of calibrated test equipment and patient simulators needed for Propaq CS functional verification. All equipment must meet manufacturer specifications and be traceable to national calibration standards.

Ranked causes

  1. 1. Equipment not calibrated to specifications (rare)
First check

Obtain required pressure test equipment

Test point
Equipment inventory
Expected
Digital pressure meter 0-300 mmHg with squeeze bulb (Netech Digamano equivalent), cuff calibration kit PN 008-0012-XX

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

Rubber gasket loose or displaced

Interface Chassis and Front Chassis rubber gaskets recessed around perimeter are loose, displaced, or unseated

Ranked causes

  1. 1. Gasket displacement during assembly/disassembly (occasional)
First check

Inspect rubber gaskets around Front Chassis perimeter

Test point
Recessed gasket areas on Front Chassis perimeter
Expected
Gaskets properly seated in recess on all sides

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

Self-test failure on power-on

Monitor displays error code or failure message during startup self-test instead of reaching Main Menu

Ranked causes

  1. 1. Hardware or software integrity failure detected by self-test (unknown)
First check

Identify error code or failure message displayed

Test point
Monitor startup screen
Expected
If Main Menu displayed, all tests passed; if failure message shown, note error code

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

Side panel installation improper fit caution

Side panel does not seat flush with Rear Chassis exterior or clamp does not secure properly

Ranked causes

  1. 1. Side panel not completely seated in Rear Chassis (common)
First check

Inspect side panel seating before clamp installation

Test point
Side panel edges along entire perimeter
Expected
Side panel flush with exterior of Rear Chassis on all sides

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

Side panel removal difficult caution

Adhesive gasket around side panel requires considerable force to separate from Rear Chassis

Ranked causes

  1. 1. Adhesive gasket seal between side panel and Rear Chassis (common)
First check

Verify no components are being pried against during panel removal

Test point
Side panel perimeter
Expected
No prying force against interior components

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

Static discharge damage to PROM caution

PROM modules damaged by electrostatic discharge during handling or installation

Ranked causes

  1. 1. Electrostatic discharge during PROM handling or installation (occasional)
First check

Inspect PROM electrical function after installation

Test point
PROM module
Expected
Normal operation and software load

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

Temperature calibration error

Temperature circuitry out of calibration, temperature channel disabled

Ranked causes

  1. 1. Temperature circuit out of calibration (common)

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

Error codes

CodeMeaningTriggerSeverity
CALIBRATION ERROR-SERVICE REQUIRED - (SCO2)CO2 bench calibration error detectedCO2 bench calibration failureerror
CALIBRATION ERROR, TEMP DISABLEDTemperature circuitry out of calibration; temperature channel disabledMonitor detects temperature sensor calibration out of rangeerror
CUFF FAULT: NIBP DISABLED, SERVICE REQUIREDNon-invasive blood pressure system fault detectedSingle fault encountered in NIBP systemerror
CUFF FAULT: NIBP DISABLED, SERVICE REQUIREDSingle fault detected in NIBP systemNIBP system failure during operationerror
CUFF FAULT: NIBP DISABLED, SERVICE REQUIREDNIBP measurement system has single fault; channel disabled until repairedNIBP system fault detectederror
DEGRADED WAVEFORM, CHECK ADAPTER - (MCO2)CO2 waveform quality degraded; may indicate contaminated adapter or faulty light sourceDegraded CO2 waveform detectedwarning
DEGRADED WAVEFORM, CHECK ADAPTER - (MCO2)CO2 waveform degraded or weakReduced signal quality from sensorwarning
DEGRADED WAVEFORM-SERVICE REQUIRED - (SCO2)Sidestream CO2 waveform degraded; possible contamination or light source failureDegraded sidestream CO2 waveformerror
ECG FAULTECG signal loss or lead disconnection detectedSingle ECG lead disconnected from patient simulator or monitor inputwarning
EQUIPMENT ALERT / ECG FAULT / MULTIPLE LEAD FAILMultiple ECG leads disconnected or multiple ECG channel failuresTwo or more ECG leads disconnected from monitor input or simulatorerror
EQUIPMENT ALERT - MULTIPLEMultiple equipment failures or faults detected (software 3.6x and greater)Two or more ECG leads disconnected or multiple system faults detectederror
LACK OF WAVE, CHECK ADAPTER, SENSOR - (MCO2)CO2 waveform absent or undetectable; adapter or sensor faultNo CO2 waveform detectederror
LACK OF WAVEFORM-SERVICE REQUIRED - (SCO2)Sidestream CO2 waveform absent; possible contamination or light source failureNo sidestream CO2 waveform detectederror
MOTOR FAILURE-SERVICE REQUIRED - (SCO2)CO2 bench motor drive failure detectedMotor drive in CO2 bench failederror
OCCLUSION-CHECK EXHAUST PORT/TUBING - (SCO2)Exhaust port or tubing occlusion detectedOcclusion detected at exhaust after removing external blockagewarning
OCCLUSION-CHECK EXHAUST PORT/TUBING - (SCO2)Sidestream CO2 exhaust tubing or port occluded; pump defect if error persistsSidestream CO2 exhaust occlusion detectedwarning
PROGRAM FAULT: SETTINGS LOST, TIME/DAY RESETDrained battery causing loss of stored settingsMonitor powered on with depleted backup batterywarning
PROGRAM FAULT: SETTINGS LOST, TIME/DAY RESETMonitor settings and time/date have been reset to factory defaultsMonitor turned on after drained batterywarning
PUMP FAILURE, SERVICE REQUIRED - (SCO2)Sidestream CO2 pump failure or tubing kinkedPneumatic pump or tubing failureerror
RESP FAULTRespiration signal loss or impedance measurement failureRespiration lead disconnected or impedance measurement out of rangewarning
SENSOR FAILURE, CALIBRATION ERROR - (MCO2)CO2 sensor calibration failure detectedSensor calibration errorerror
SENSOR FAILURE - EEPROM - (MCO2)CO2 mainstream sensor EEPROM checksum error; CO2 channel disabledSensor EEPROM checksum failure detectederror
SENSOR FAILURE - EEPROM - (MCO2)Sensor EEPROM failure detected (typically checksum error)Sensor EEPROM checksum error or failureerror
SENSOR FAILURE, HEATER - (MCO2)CO2 sensor temperature control hardware failure detectedSensor heater hardware failureerror
SENSOR FAILURE, MOTOR DRIVE - (MCO2)Mainstream CO2 sensor motor drive hardware failure; channel disabledSensor motor drive hardware failureerror

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

Community

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.