The control unit is not programmed
â–¶ How to fix
The control unit must be programmed.Contact an Allison dealer.
What you'll see
No driver-visible symptom recorded.
System reaction
The Allison fault code number is: P0602.The control unit switches to the basic program mode.The control unit prevents any gear being engaged.
Diagnostic depth
Detection
Calibration in control unit is not valid.
Possible cause
Control unit is not calibrated or incorrectly calibrated.