Detroit DD15 GHG14 (2014-16) Fault Code: SPN 655 FMI 7 (MCM) Injector Cylinder #5 Needle Control Valve Stuck Open

NOTE: Please see the step by step troubleshooting procedures for this specific code.

NOTE: If code 168-xx or 723-xx present, fix those first.

PROBABLE CAUSES:
1. Front fuel injector harness connection (14-pins).
2. Injector harness.
3. Failed injector.
4. Engine side harness failure.
5. MCM (Engine ECM) failure.