Service VME - Automatic Leveling Feature of the Rear Suspension Is Not Functioning - air ECAS ECU height left low right U1000 ZM6

When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.

Should a customer indicate that the automatic leveling feature of the rear suspension is not functioning, check for the presence of an ECAS ECU DTC U1000 set as a current code. Interruption in communication between other electronic modules on the vehicle, causes the ECAS ECU to set code U1000. If communication between the electronic modules is restored, the functionality of the rear air suspension is also restored, but DTC U1000 remains as a current code. If communication between electronic modules is not restored, the electronically controlled rear air suspension will not function and simply remain at its current level. Once the communication failure between electronic modules is corrected, clear DTC U1000.

Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. This diagnostic approach was developed for the vehicle with the VIN you entered and should not be automatically be used for other vehicles with similar symptoms.