CAT 3406E (Prefix 5DS or 1LW) Fault Code: 14 PID: 122 SPN: FMI: 5 Med/High Retarder current low

Posted by PerDiezel Solutions on January 13, 2026

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 solenoids for cylinders 1, 2, 5, and 6.
•The engine retarder switch is in the medium 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

CAT 3406E (Prefix 5DS or 1LW) Fault Code: 14 PID: 121 SPN: FMI: 6 Low/High Retarder current high

CAT 3406E (Prefix 5DS or 1LW) Fault Code: 14 PID: 121 SPN: FMI: 5 Low/High Retarder current low

CAT 3406E (Prefix 5DS or 1LW) Fault Code: 13 PID: 174 SPN: FMI: 4 Fuel Temperature voltage low

CAT 3406E (Prefix 5DS or 1LW) Fault Code: 13 PID: 174 SPN: FMI: 3 Fuel Temperature voltage high

CAT 3406E (Prefix 5DS or 1LW) Fault Code: 12 PID: 111 SPN: FMI: 2 Coolant Level signal invalid

CAT 3406E (Prefix 5DS or 1LW) Fault Code: 02 PID: 244 SPN: FMI: 2 Event Recorder Data Lost

WARNING!