Inserting Transmitter Key, Electronic Ignition/Starter Switch

When inserted into the electronic ignition / starter switch control module (N73) a the power supply to the transmitter key (A8/1) is established inductively via a coil in the electronic ignition / starter switch control module (N73) so that the vehicle can be started even when the key battery is flat. The function buttons on the transmitter key are not active while the key is in the electronic ignition / starter switch control module (N73).

Mutual infrared communications occur between the transmitter key and the electronic ignition / starter switch control module (N73). The transmitter key identifies itself to the electronic ignition / starter switch control module (N73). If the key's identification is valid, the rotary lock in the electronic ignition / starter switch control module (N73) is enabled. The transmitter key can now be turned.

When the transmitter key is in the electronic ignition / starter switch control module (N73), the anti-theft alarm (ATA, code 551a) is deactivated and the interior switches are enabled, although the vehicle is not unlocked.