Cummins ISM CM870 (2003-06) Fault Code: 547 PID: P094 SPN: 94 FMI: 4/4 Rail Fuel Pressure Sensor Circuit – shorted low. Low signal voltage detected at rail fuel pressure circuit.

Description

The rail fuel pressure sensor shares supply and return wires in the engine harness with other sensors. Opens and shorts in the engine harness can cause multiple fault codes to be active. Before troubleshooting Fault Code 547, check for multiple faults.

Possible causes:

1)Open signal circuit in the engine harness, connectors, or sensor.
2)Signal circuit shorted to ground in the engine harness, connector, or sensor.
3)Failed sensor.

Possible repairs:

1)Replace the rail fuel pressure sensor.
2)Repair or replace the engine harness.
3)Replace the ECM.