Gearbox oil
Check whether the vehicle has been driven extremely hard without lock-up when this fault code is generated. Contact an Allison dealer.
What you'll see
No driver-visible symptom recorded.
System reaction
The Allison fault code number is: P0218. The control system switches to Hot Mode, which means that the 4th gear is the highest possible gear.Gear changing adaptation is switched off.The fault code can only be set if the engine speed is greater than 200 rpm.This fault code can be a result of fault code 1 809 being set.The fault code is cleared automatically, when the vehicle has completed 40 start-up cycles without the fault being detected again.
Diagnostic depth
Gearbox oil temperature is too high.
Long or heavy driving without lock-up or long periods of retarder braking can cause this fault code. The fault code is set when the oil has been hotter than 126°C for at least 10 seconds. The fault can also be caused by a valve jamming.