Control system performance
â–¶ How to fix
Contact an Allison dealer.
What you'll see
No driver-visible symptom recorded.
System reaction
The Allison fault code number is: P0701.Control unit locks the gearbox in neutral position.The fault code is cleared automatically, when the vehicle has completed 40 start-up cycles without the fault being detected again.
Diagnostic depth
Detection
Reply signal from PS1 does not correspond to what the signal should show.
Possible cause
The reason could be one of the following: Low gearbox oil level.C1 or C2 may be stuck.Gear shift solenoid SS1 may be faulty.PS1 may be faulty or stuck.Short circuit to ground.Worn out or faulty oil pump.