The automatic start is intended to prevent the driver from pressing the starter for longer than necessary. This prevents any unnecessary noise generation. Even under cold start conditions, the driver only needs to press the start button briefly; the DME takes on the rest of the task.
The DME is notified of the start request via the Car Access control module. The DME checks the start conditions engine speed, selector lever setting, EWS signal and activates the start-locking relay through a separate output. The starter motor is operated via this relay.
The start-locking relay is activated until the engine starts. If the engine does not start up, the start-locking relay is switched off after 20 seconds. If the engine is blocked, the start-locking relay is switched off after a few seconds.
The following fault states are detected:
- Start request by Car Access control module while engine is running
- Sticking start-locking relay
- Defective final stage of the DME
- Short circuit in activation wire
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