CAT 3406E (Prefix 1MM or 2WS) Fault Code: 14 PID: SPN: 121 FMI: 6 Low/High Retarder current high
The Engine Control Module (ECM) detects the following conditions:
•The ECM detects a low current condition (open circuit) for one second while the ECM is attempting to energize the solenoid for cylinders 3 and 4.
•The engine retarder switch is in the low or high position.
Probable Causes:
1) ECM Connection/Harness
2) Harness between the ECM and valve cover base
3) Engine retarder solenoid failure
4) Harness under valve cover
5) ECM Failure
6) Harness at bulkhead connector