Supply voltage too high from actuator 1
â–¶ How to fix
Check the control unit's wiring. Contact an Allison dealer
What you'll see
No driver-visible symptom recorded.
System reaction
No system-reaction text recorded.
Diagnostic depth
Detection
Supply voltage for actuator 1 (HSD1) is too high.
Possible cause
The control unit has detected 6 V or more in actuator 1 (HSD1) circuit after two solenoids have indicated a fault. This can be caused by a short circuit to battery in the actuator 1 circuit.