Ignition Switch: Description and Operation

IGNITION SWITCH AND IMMOBILIZER SYSTEM

OPERATION

Ignition key illumination timer circuit
- When, with the ignition switch turned to the OFF position, the driver's door is opened (door switch is switched ON), the ETACS-ECU timer circuit is activated, the ETACS-ECU sends a signal to the instrument panel ECU which switches the ignition key hole illumination light on for 10 seconds.

When the ignition switch is turned to the ON position while the timer circuit is activated, the key hole illumination light is switched off.

Immobilizer System
- The immobilizer system consists of the ignition key, the key ring antenna, the immobilizer-ECU, and the PCM. The ignition key has a built-in transponder. The key ring antenna is installed on the steering lock key cylinder. Only the registered ignition key permits the engine to start, therefore, the engine can never be started by means of a forged key or by connecting the ignition wiring directly. The system is significantly safe and reliable against theft. In addition, the driver has only to turn the ignition switch to the "ON" position to activate the immobilizer system. If the requirements for starting are not satisfied, the engine will be immobilized. If the ignition key is lost or another ignition key is added, the encrypted code can be registered or erased by using scan tool MB991502.