Control unit, 30 voltage too high
Check the battery, associated cable harness and the vehicle alternator. Ensure that the cable harness between gearbox and control unit is not damaged. If no fault is found, contact an Allison dealer.
What you'll see
No driver-visible symptom recorded.
System reaction
The Allison fault code number is: P0883.For the fault code to be set, the engine speed must be higher than 450 rpm for more than 10 seconds.The fault code is cleared automatically, when the vehicle has completed 40 start-up cycles without the fault being detected again.
Diagnostic depth
The control unit 30 voltage has exceeded a specified value.
The cause of this fault code can be: Fault on the vehicle's charging system.Loose contact or damaged cable harness.A 12 V control unit has been installed in a 24 V electrical system.