Lost Communication With Vehicle Immobilizer Control Module
Troubleshoot via the coordinator. If there have not been any DTCs generated in the coordinator and the driver does not notice any running problems the only action that is needed is to delete the DTC. After completing the troubleshooting, clear the DTCs in the EMS and then check to see whether the DTCs return.
What you'll see
No driver-visible symptom recorded.
System reaction
The starter motor is blocked. If the vehicle has a speed over 20km/h the accelerator is set to 0% and the engine control to low idle speed (500 rpm) as long as the fault is active. If the vehicle has a speed below 20km/h the fuel injection is shut off, i.e. the engine will stop or not start as long as the DTC is active.
Diagnostic depth
The COO may have been unable to verify the starter key or the validation between the COO and EMS took too long. The EMS could also be turned off improperly last time. Timeout at immobilizer timer in E2 or RAM could also lead to this DTC.
The coordinator may have been disconnected when starting the engine control unit or the coordinator may have been unable to verify the starter key. Another cause can be that U15 has been switched off one or several times very short time after switching on (before validation has been finished, which takes about 1 second) and the remaining E2-timer has not been enough to complete the validation. U30 could also have been removed before U15 was switched off. The latest immobilizer status was not saved, e.g. when the battery master switch has been used or when a reset of the EMS has occurred.