Short circuit on the output shaft rotational speed sensor
Check the cable harness and renew the rotational speed sensor.Contact an Allison dealer if the fault persists.The fault code can be cleared manually using SDP3 or using Allison's diagnostic tool. The fault code is cleared automatically, when the vehicle has completed 40 start-up cycles without the fault being detected again.
What you'll see
No driver-visible symptom recorded.
System reaction
The fault code can be set if the following conditions are met:The components are supplied with voltage.The 15 voltage is above 9 V and below 32 V.The vehicle control unit is calibrated for a fire engine.Gear changing has been completed.The engine is running.Current gear is not neutral.The hydraulics must not have been affected by lost 15 voltage.The oil sump temperature is above -1.1°C.The turbine speed is greater than 600 rpm.Yellow warning lamp comes on.The fault code is stored in the memory.The gearbox retains the current gear if driving with range gear forward and a gear change took place when the fault occurred.The gearbox returns to the previous gear if driving with range gear forward and a gear change is in progress when the fault occurs. The gearbox will then carry out the requested gear change.Lock-up cannot be locked.The control unit shuts off gear changing adaptation.
Diagnostic depth
The control unit has detected a short circuit in the output shaft rotational speed sensor.
Possible causes:Damaged cable harness.Defective rotational speed sensor.There are changes of at least 600 rpm on the shaft rotational speed when the current gear is in neutral.