Supply voltage too low from actuator 1
â–¶ How to fix
Check the control unit cable harness. Contact an Allison dealer.
What you'll see
No driver-visible symptom recorded.
System reaction
The Allison fault code number is: P0658.All solenoids are shut off. The gear selector position and the hydraulic position of the solenoids determine which gear is activated in the gearbox.The fault code is cleared automatically, when the vehicle has completed 40 start-up cycles without the fault being detected again.
Diagnostic depth
Detection
Supply voltage for actuator 1 (HSD1) is too low.
Possible cause
The control unit has detected less than 6 V in two solenoids in the actuator 1 circuit. This can be caused by a short circuit to ground in the actuator 1 circuit.