Alarm Module: Testing and Inspection

Inspection of Immobilizer Control Module (ICM) and Its Circuit

Immobilizer Control System Wiring Circuit Diagram

ICM and its circuit can be checked at ICM wiring connector by measuring voltage.

NOTE:

If you connect a voltmeter or ohmmeter directly to the ICM by disconnecting the ICM connector, you can damage the ICM.

Never connect a voltmeter or an ohmmeter directly to any terminal on the ICM by disconnecting the ICM connector.

Voltage Check

1) Remove ICM (1) from steering lock assembly or steering lock unit referring to Service and Repair Immobilizer Control Module (ICM) Removal and Installation.
2) Connect ICM connector (2) to ICM.
3) Check voltage at each terminal.

NOTE:
As each terminal voltage is affected by the battery voltage, confirm that it is 11 V or more when the ignition switch is turned to ON position.













Reference Waveform










NOTE:

When ECM cannot read the transponder code at the first try, ECM tries to read the transponder code repeatedly up to 8 times. The second waveform is the example showing that ECM read the transponder code successfully at the second try.