General Description; Immobilizer Control System Introduction; On-Board Diagnostic System Description (Self-Diagnosis Function) - Suzuki SX4 Service Manual

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• Do not leave ignition key in a place where
temperature is high. High temperature may cause
damage to the transponder built in the ignition key.

Immobilizer Control System Introduction

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. For immobilizer control
system components location, refer to "Immobilizer Control System Components Location".
• 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. (In
addition to the above operation, ECM also turns the immobilizer indicator light ON and OFF when some trouble is
detected in the keyless start system.)

On-Board Diagnostic System Description (Self-diagnosis Function)

ECM diagnoses if there is any trouble with the immobilizer control system. The diagnostic information is stored as the
diagnostic trouble code (DTC) in ECM. To read the diagnostic information, use SUZUKI scan tool referring to "DTC
With the ignition switch turned ON (but the engine at stop) regardless of the condition of the engine and emission
control system, ECM indicates whether there is any trouble with the immobilizer control system or not by either lighting
ON or flashing ON and OFF the immobilizer indicator light.
Immobilizer indicator light lights ON:
No trouble exists in the immobilizer control system. (After starting up the engine, the light turns OFF.)
Immobilizer indicator light flashes ON and OFF:
There is some trouble in the immobilizer control system or in the keyless start system. Its diagnostic information is
stored in ECM.
• Do not turn ignition switch to ON position by bringing
radio antenna close to coil antenna. Or, the
immobilizer control system may detect some
abnormal condition and prevent the engine from

General Description

Immobilizer Control System:


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