Cummins ISB CM850 (2003-06) Fault Code: 1845 PID: SPN: 97 FMI: 3 Water-in-Fuel Indicator Sensor Circuit – Voltage Above Normal or Shorted to High Source (For Generator Engines Only). High voltage detected at the water-in-fuel indicator circuit.

The water-in-fuel sensor is located in the Stage 1 filter housing. It is a serviceable part.

Possible causes:

1)Open return or signal circuit in the harness, connectors, or sensor.
2)SIGNAL wire shorted to sensor supply or battery voltage.

Possible repairs:

1)Replace the damaged section of harness or damaged water-in-fuel indicator sensor.
2)Replace the water-in-fuel indicator sensor.
3)The removal and installation of the connector may correct the fault.
4)Replace the ECM.
5)Replace the damaged section of the engine harness.
6)Replace the damaged section of the engine harness.