Immobilizer Control System Introduction

WARNING: This page is about a different car, the 2008 Suzuki Grand Vitara. However, it is still accessible from the selected car via links, so may be relevant.

The immobilizer control system is an anti-theft device that immobilizes the vehicle. It stops the engine from working and prevents the vehicle from being stolen. It mainly consists of the following components.

Engine Control Module (ECM)
Immobilizer control module (ICM) with the built-in coil antenna
Ignition key with the built-in transponder

A code called the transponder code is memorized in the transponder. And, the code is registered with ECM. Basically, when the ignition switch is turned ON, ECM reads the code by the coil antenna. Then, if the code in transponder in the ignition key does not match with the one registered with ECM, ECM stops the operation of the fuel injection so as not to start up the engine and turns the immobilizer indicator light ON and OFF using CAN communication lines. The immobilizer control system of the CANADA model also has an ID controller. When the ignition switch is turned ON, ECM executes verification with the ID controller at the same time as the above operation and judges whether to start up the engine or not. (In addition to the above operation, ECM also turns the immobilizer indicator light ON and OFF when some trouble is detected in the immobilizer control system including ID controller.)