Cummins ISB CM850 (2003-06) Fault Code: 2274 PID: 411 SPN: 411 FMI: 4 EGR valve differential pressure sensor circuit – shorted low. Low signal voltage detected on the EGR valve differential pressure sensor circuit.

The EGR valve differential pressure sensor shares supply and return wires in the engine harness with other sensors. Open circuits and short circuits in the engine harness can cause multiple fault codes to be active. Before troubleshooting Fault Code 2274, check for multiple faults.

Possible causes:

1)Open signal circuit in the engine harness, connections, or sensor
2)Supply circuit open or shorted to ground
3)Sensor shorted to ground.

Possible repairs:

1)Replace the EGR valve differential pressure sensor.
2)Replace the ECM.
3)Replace the engine harness.