Antitheft and Alarm Systems: Description and Operation
IMMOBILIZER SYSTEMThe immobilizer system consists of the ignition key, the key ring antenna, the immobilizer-ECU, and the ECM
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 the engine are not satisfied, the engine will be immobilized.
If a registered ignition key is lost, all your ignition keys need to be registered again using scan tool MB991502 (MUT-II) to ensure security. An additional ignition key can be registered as follows (only if no ignition keys are lost):
- Using scan tool MB991502 (MUT-II)
- Registering new ignition keys by operating ignition keys that already have been registered
CONSTRUCTION DIAGRAM:
1. When the ignition switch is turned to "ON" position, the ECM
2. When the immobilizer-ECU receives the requirement from the ECM
3. The immobilizer-ECU judges the encrypted code with its code logic in itself. If they are identical, the immobilizer-ECU sends the encrypted code to the ECM
4. If the ECM
SIMPLIFIED WIRING SYSTEM
Theft-alarm System Operation
If a door, trunk lid or hood is opened, when the theft-alarm system has been armed the horn (theft-alarm horn and horn) will sound and headlights flash (high- beam) intermittently for a period of three minutes.
Panic Alarm Function
With the theft-alarm function armed, pressing the panic button on the keyless entry system transmitter causes the horn (theft-alarm horn and horn) to sound for about three minutes in an attempt to prevent theft. The alarm is turned off by pressing any switch on the transmitter.