Cummins ISB CM850 (2003-06) Fault Code: 234 (Auto) PID: 190 SPN: 190 FMI: 0 Engine Crankshaft Speed/Position – Data Valid But Above Normal Operating Range – Most Severe Level. Engine speed signal indicates engine speed above engine protection limit.

Posted by PerDiezel Solutions on January 18, 2026

Possible causes:

1)External fuel sources drawn into the intake air passage
2)Reverse powering (motoring) of the engine
3)Tampering of the engine speed/position sensors.

Inspect the intake manifold for sources of flammable vapors. Check the turbocharger seals to verify that there are no oil leaks. Inspect the engine speed/position sensors for damage or tampering.

The sensor return configuration for Euro 4 ISB engines has been changed for automotive wiring harnesses manufactured from February 2012 onward. The new style wiring harnesses can be be identified using the method below:

1)Disconnect the ECM connector
2)Disconnect the camshaft position sensor
3)Disconnect the intake manifold pressure/temperature sensor
4)Check for continuity between the intake manifold pressure/temperature sensor RETURN pin and the camshaft position sensor RETURN pin
5)Check for continuity between ECM pin 47 and the camshaft position sensor RETURN pin
6)Use the table below to determine which harness is fitted to the engine.

NOTE: QSB engines, all C series engines, and all L series engines are not affected by this change.

Possible repairs:

1)Replace the crankshaft engine speed sensor.
2)Replace the camshaft engine position sensor.
3)Replace the ECM.

Cummins ISB CM850 (2003-06) Fault Code: 227 (Marine) PID: SID 232 SPN: 1080 FMI: 3 Sensor Supply 2 Circuit – Voltage Above Normal or Shorted to High Source. High voltage detected at sensor supply number 2 circuit.

Cummins ISB CM850 (2003-06) Fault Code: 227 (Auto) PID: SID 232 SPN: 1080 FMI: 3 Sensor Supply 2 Circuit – Voltage Above Normal or Shorted to High Source. High voltage detected at sensor supply number 2 circuit.

Cummins ISB CM850 (2003-06) Fault Code: 222 PID: 108 SPN: 108 FMI: 4 Barometric Pressure Sensor Circuit – Voltage Below Normal, or Shorted to Low Source. Low signal voltage detected at barometric pressure circuit.

Cummins ISB CM850 (2003-06) Fault Code: 221 PID: 108 SPN: 108 FMI: 3 Barometric Pressure Sensor Circuit – Voltage Above Normal or Shorted to High Source. High signal voltage detected at barometric pressure circuit.

Cummins ISB CM850 (2003-06) Fault Code: 197 PID: 111 SPN: 111 FMI: 1 Coolant Level – Data Valid but Below Normal Operational Range – Moderately Severe Level. Low engine coolant level detected.

Cummins ISB CM850 (2003-06) Fault Code: 196 (3 wires) PID: 111 SPN: 111 FMI: 4 Coolant Level Sensor 1 Circuit – Voltage Below Normal or Shorted to Low Source. Low signal voltage detected at engine coolant level circuit.

WARNING!