Start

Start







The starter motor (6/25) is powered via the starter motor relay (2/35). The relay is controlled by the engine control module (ECM) (4/46). The start process is as follows:
1. The ignition key is turned to start position (position III)
2. A high signal (U(bat)) from the ignition switch (3/1) is transmitted to the engine control module ECM) and starter relay via the central electronic module (CEM) and integrated relay/fusebox in the engine compartment. The engine control module (ECM) interprets this high signal as a request to activate the starter motor
3. The engine control module (ECM) activates the starter motor solenoid by grounding the relay for the starter motor relay. The relay is powered by the ignition switch
4. The relay closes the circuit between the starter motor solenoid and the fuse in the integrated relay/fusebox in the engine compartment, activating the starter motor
5. The engine control module (ECM) activates the starter motor until the ignition key is released from the start position (position III).

The starter motor will not be activated if:
- the function for electronic Immobilizer does not allow start. The engine control module (ECM) receives signal regarding if the electronic immobilizer is active or inactive, from the central electronic module (CEM) via the CAN net.
- the gear selector is not in position "P" or "N" (automatic transmissions). The engine control module (ECM) receives a signal indicating the position of the gear selector from the transmission control module (TCM) (4/28) via both the controller area network (CAN) and from a directly connected cable between the engine control module (ECM) and transmission control module (TCM).
- the clutch pedal is released (manual transmissions, certain markets). The engine control module (ECM) receives a signal indicating the position of the clutch pedal from the central electronic module (CEM) via the controller area network (CAN).