Cummins ISX CM870 (2003-06) Fault Code: 2272 PID: P27 SPN: 27 FMI: 4/4 Exhaust Gas Recirculation (EGR) Valve Position Circuit – Voltage Below Normal or Shorted to Low Source. Low signal voltage detected at EGR valve position sensor circuit.

The EGR valve position sensor shares supply and return wires in the engine harness with other sensors. Open circuits and shorts circuits in the engine harness can cause multiple fault codes to be active.

Possible causes:

1)Signal circuit open or shorted to ground
2)Supply circuit open or shorted to ground
3)Sensor shorted to ground
4)Damaged EGR valve.

Possible repairs:

1)Replace the EGR valve assembly.
2)Replace the ECM.
3)Repair or replace the appropriate harness.