10C
Immobilizer Control System Introduction
The immobilizer control system designed to prevent vehicle burglar consists of the following components.
Vehicle not equipped with air bag system [A]
• Engine Control Module (ECM)
• Immobilizer Control Module (3)
• Ignition key with built-in transponder (Knob color: Black) (2)
• Coil antenna (1)
Vehicle with air bag system [B]
• Engine Control Module (ECM)
• Immobilizer Control Module with coil antenna (7)
• Ignition key with built-in transponder (Knob color: Dark gray) (8)
Operation of this system is as follows.
1) Each ignition key has its own code (Transponder code) stored in memory. When the ignition switch is turned ON, Immobilizer Control Module tries to read the Transponder code through its coil antenna installed to the steering lock assembly.
2) Immobilizer Control Module compares the Transponder code read in coil antenna and that registered in Immobilizer Control Module and checks if they match.
3) When it is confirmed that two Transponder codes watch each other as described above, Immobilizer Control Module and ECM check if ECM/Immobilizer control Module codes registered in them respectively match.
4) Only when it is confirmed that ECM/Immobilizer Control Module codes match, the engine starts running. If Transponder codes in Step (2) or ECM/Immobilizer Control Module codes in Step (3) do not match, ECM will stop operation of the injector and ignition of spark plug.
Immobilizer Control Module
Immobilizer Control Module is installed to the steering lock assembly or the underside of the instrument panel at the driver’s seat side.
As main functions, Immobilizer Control Module checks matching not only between the Transponder Code transmitted from the ignition key and that registered in Immobilizer Control Module (Up to 4 different Transponder codes can be registered.) but also between the ECM/Immobilizer Control Module code transmitted from ECM and that registered in Immobilizer Control Module. In addition, it has an on-board diagnostic system (self-diagnosis function) which is described in On-Board Diagnostic System (Self-Diagnosis Function) Description:M13A Model .
1. Immobilizer Control Module
(Vehicle not equipped with air bag system)
2. Immobilizer Control Module
(Vehicle equipped with air bag system)
3. Coil antenna
(Vehicle not equipped with air bag system)
ECM
As main functions, ECM not only checks matching of ECM/Immobilizer Control Module code but also an on-board diagnostic system (self-diagnosis function) as described in On-Board Diagnostic System (Self-Diagnosis Function) Description:M13A Model .
For installation position of ECM, refer to Engine Control Module (ECM) Removal and Installation:M13A .