CAT 3406E (Prefix 1MM or 2WS) Fault Code: 66 PID: SPN: 54 FMI: 5 Auxiliary Output #06 current low

The Engine Control Module (ECM) detects the following conditions:

•Three attempts to complete an Eaton Top 2 shift were unsuccessful.
•The “Transmission Style” is programmed to “Eaton Top 2”.

Probable Causes:

1) ECM Connector/harness
2) Shift solenoid failure
3) Shift solenoid relay
4) Wiring between shift solenoid and ECM
5) Gear ratios are programmed incorrectly in the ECM