Cummins ISB CM850 (2003-06) Fault Code: 295 PID: 108 SPN: 108 FMI: 2 Barometric Pressure ?Data Erratic, Intermittent, or Incorrect. The barometric air pressure sensor is reading an erratic value at initial key-on.

Posted by PerDiezel Solutions on January 18, 2026

The engine barometric pressure reading is compared to the other pressure sensor values at initial key-on. If the value of engine barometric pressure does not match the readings from pressure sensors within a pre-defined tolerance, this fault code is logged. To make the diagnostic run, turn the keyswitch on for 15 seconds before cranking the engine.

Possible causes:

1)Stuck in-range barometric pressure sensor reading
2)High resistance in the barometric pressure sensor signal or return lines
3)Stuck in-range intake manifold pressure sensor.

On-Board Diagnostics (OBD) Information (Euro 4 Certified Engines):

1)The ECM illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
2)The ECM turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. The MIL lamp and fault code can also be cleared using the INSITE? service tool.
3)The fault code will be cleared from memory after 40 consecutive drive cycles where the diagnostic runs and passes.

On-Board Diagnostics (OBD) Information (Euro 4 Stage 1+ Certified Engines):

1)The ECM illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
2)An engine torque derate will be activated after 50 hours of engine operation with the fault code active.
3)The ECM turns OFF the malfunction indicator lamp (MIL) after 1 ignition cycles that the diagnostic runs and does not fail. The MIL lamp cannot be cleared using the INSITE? service tool.
4)The fault code will be cleared from memory after 400 days or 9600 hours of engine operation.

Possible repairs:

1)Replace the ECM.
2)Replace the engine harness.
3)Replace the barometric pressure sensor.

Cummins ISB CM850 (2003-06) Fault Code: 294 PID: 441 SPN: 441 FMI: 4 Auxiliary Temperature Sensor Input 1 Circuit – Voltage Below Normal, or Shorted to Low Source. Low signal voltage detected at OEM auxiliary temperature circuit.

Cummins ISB CM850 (2003-06) Fault Code: 293 PID: 441 SPN: 441 FMI: 3 Auxiliary Temperature Sensor Input 1 – Voltage Above Normal, or Shorted to High Source. High signal voltage or open circuit detected at the OEM auxiliary temperature circuit.

Cummins ISB CM850 (2003-06) Fault Code: 292 PID: 441 SPN: 441 FMI: 14 Auxiliary Temperature Sensor Input 1 – Special Instructions.

Cummins ISB CM850 (2003-06) Fault Code: 291 PID: SID 248 SPN: 625 FMI: 9 Proprietary Datalink Error (OEM/Vehicle Datalink) ? Abnormal Update Rate. The ECM cannot communicate with the immobilizer anti-theft system.

Cummins ISB CM850 (2003-06) Fault Code: 288 PID: 29 SPN: 974 FMI: 19 SAE J1939 Multiplexing Remote Accelerator Pedal or Lever Data Error – Received Network Data Error. The OEM vehicle electronic control unit (VECU) detected a fault with the remote accelerator.

Cummins ISB CM850 (2003-06) Fault Code: 287 PID: 91 SPN: 91 FMI: 19 SAE J1939 Multiplexing Accelerator Pedal or Lever Sensor System Error – Received Network Data Error. The OEM vehicle electronic control unit (VECU) detected a fault with its accelerator pedal.

WARNING!