Eaton Gen 2 (AutoShift) Fault Code: 43 PID: SID 36 FMI: 4 Range Valve

Overview:
Fault Code 43 indicates an electrical failure of the solenoids that control the range shift.

Detection:
Starting at key on and throughout operation, the Transmission Controller constantly measures this Range Valve circuit. A failure of short to battery, short to ground or open circuit is detected.

Fallback:
This fault causes a 5-speed fallback and the transmission stays in either low range or high range. When the vehicle comes to a stop, an attempt to shift into low range is made.

Possible Causes:
1) Range Valve
2) Transmission Harness
3) Transmission Controller

Shop Talk:
Key on. If the fault is present, the system should automatically detect the problem and set the code. If the fault is not present at key on, operate the vehicle and attempt to duplicate the driving conditions that triggered the fault code. Possible triggers include heat, vibration.