Eaton Gen 1 (AutoShift) Fault Code: 65 PID: SID 251 FMI: 4 Low Motor Voltage

Posted by PerDiezel Solutions on May 12, 2026

Overview:
This code indicates the Transmission ECU has detected low battery power supply to the electric shifter motors.

Detection:
Starting at key on and throughout operation, the Transmission ECU constantly measures the motor voltage. If the reading is low, the fault code is set.

Fallback:
This causes an In Place fallback.

Required Tools:
1) Basic Hand Tools
2) Digital Volt/Ohm Meter
3) AutoSelect/AutoShift Troubleshooting Guide

Possible Causes:
1) Battery bus fuse/circuit breaker is open
2) Low batteries
3) Corroded or loose contacts
4) Failed power interface module
5) Malfunctioning transmission ECU

Eaton Gen 1 (AutoShift) Fault Code: 63 PID: SID 40 FMI: 6 Gear Select Motor

Eaton Gen 1 (AutoShift) Fault Code: 63 PID: SID 40 FMI: 5 Gear Select Motor

Eaton Gen 1 (AutoShift) Fault Code: 61 PID: SID 39 FMI: 6 Rail Select Motor

Eaton Gen 1 (AutoShift) Fault Code: 61 PID: SID 39 FMI: 5 Rail Select Motor

Eaton Gen 1 (AutoShift) Fault Code: 58 PID: PID 191 FMI: 2 Output Shaft Speed Sensor

Eaton Gen 1 (AutoShift) Fault Code: 57 PID: PID 160 FMI: 2 Main Shaft Speed Sensor

WARNING!