Cummins ISB CM850 (2003-06) Fault Code: 2351 PID: SID 146 SPN: 2791 FMI: 4 EGR Valve Control Circuit – Voltage Below Normal or Shorted to Low Source. Low voltage detected at the EGR valve motor circuit.

Cummins ISB CM850 (2003-06) Fault Code: 2351 PID: SID 146 SPN: 2791 FMI: 4 EGR Valve Control Circuit – Voltage Below Normal or Shorted to Low Source. Low voltage detected at the EGR valve motor circuit.

The ECM monitors the voltage level of the circuit and logs a fault code if the voltage level indicates a short to ground. This fault is always set inactive when the keyswitch is turned ON. If there is a failure of this circuit, the fault code will not be set active until the valve has been actuated. For these reasons, this troubleshooting tree must be used of both active and inactive fault codes. This also means that the only sufficient way for making sure that the repair is effective is to run the INSITE? EGR Valve Test. Running the engine may not be enough to verify that the fix was effective.

A possible cause of this fault is EGR valve motor output (+ or -) leads shorted to ground in the harness, EGR valve motor, or ECM.

Possible repairs:

1)Replace the EGR valve assembly.
2)Repair or replace the engine harness.
3)Replace the ECM.
4)The removal and installation of the connector may correct the problem.