Cummins ISB CM850 (2003-06) Fault Code: 1846 PID: SPN: 97 FMI: 4 Water-in-Fuel Indicator Sensor Circuit – Voltage Below Normal or Shorted to Low Source (For Generator Engines Only). Low voltage detected at the water-in-fuel indicator circuit.

Cummins ISB CM850 (2003-06) Fault Code: 1846 PID: SPN: 97 FMI: 4 Water-in-Fuel Indicator Sensor Circuit – Voltage Below Normal or Shorted to Low Source (For Generator Engines Only). Low voltage detected at the water-in-fuel indicator circuit.

The water-in-fuel indicator sensor is integrated into the bottom of the suction fuel filter. The first stage fuel filter is located on the intake side of the engine.

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

Possible causes:

1)SIGNAL circuit shorted to ground in the harness, sensor, or connector.

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 damaged section of the ECM harness or damaged connector.
5)Replace the ECM.