Cummins ISM CM875 (2003-06) Fault Code: 2273 PID: P411 SPN: 411 FMI: 3/3 Exhaust Gas Recirculation Valve Delta Pressure Sensor Circuit – Voltage Above Normal or Shorted to High Source. High signal voltage detected at the EGR differential pressure sensor circuit.

The EGR differential 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, check for multiple fault codes.

Possible causes:

1)Open return circuit in the harness, connectors, or sensor
2)Signal circuit shorted to sensor supply or battery voltage
3)Supply circuit shorted to battery voltage.

Possible repairs:

1)Repair the exhaust leaks at the pressure tubes.
2)Replace the EGR differential pressure sensor.
3)Replace the ECM.
4)Repair or replace the engine harness.