Cummins ISM CM875 (2003-06) Fault Code: 2278 PID: S27 SPN: 641 FMI: 4/4 Turbocharger Control Valve Circuit – shorted low. Low voltage detected at turbocharger control valve circuit.

Turbocharger Control Valve Command can be monitored with the INSITE? electronic service tool. This parameter represents the ECM command to the turbocharger control valve which in turn controls the variable geometry actuator position.

Possible causes:

1)Signal circuit short circuit to ground in the engine harness, connectors, or turbocharger control valve.

Possible repairs:

1)Replace the turbocharger control valve.
2)Replace the ECM.
3)Repair or replace the engine harness.