Start Control Module (SCU)
The start control module (SCU) (3/1) is in the dashboard beside the steering wheel. The start control module (SCU) contains a cylinder for the key, an antenna ring and four contact breakers. There is one contact breaker for each of the three key positions (I-III) and one to indicate that the key is in the ignition switch.
The contact breaker for key in is designated Key-in contact breaker. The key-in contact breaker closes when the key is inserted in the ignition and indicates to the central electronic module (CEM) that the car is about to be started.
The antenna ring is activated by the central electronic module (CEM) when the signal from the key-in contact breaker has been received. The antenna ring allows the central electronic module (CEM) to communicate with the transponder in the ignition key.
The key does not need to be in the ignition switch if there is a keyless vehicle module (KVM) in the vehicle. There is a starter button instead. The starter button must be pressed in before it can be turned from position 0 to I. This activates the key-in switch. The identity of the key is then checked via the antennas in the passenger compartment instead. These antennas are connected to the keyless vehicle module (KVM).