Eaton Gen 2 (AutoShift) Fault Code: 91 PID: SID 236 FMI: 5 Power Connection

Overview:
Fault Code 91 indicates an excessive resistance has been detected between the power supply source (battery or starter) and the Transmission Controller.

Detection:
The fault is detected during power down.

Possible Causes:
1) Vehicle Harness between battery or starter and Transmission Controller.

Shop Talk:
Key off. If the fault is present, the system will automatically detect the problem during system calibration and set the code Inactive. Possible
triggers include corrosion on main battery power and ground.