Gear changing prevention function
â–¶ How to fix
Check that there is no damage or short circuits in the external cable harness or any switch connected to pins 1, 3 and 42.If no fault is detected, contact an Allison dealer.
What you'll see
No driver-visible symptom recorded.
System reaction
No system-reaction text recorded.
Diagnostic depth
Detection
Input signals to the control unit for activation of the gear changing prevention function are incorrect.
Possible cause
The control unit has detected two different states on pins 1 and 42 in the control unit.