Immobilizer System

Immobilizer System

How the Circuit Works

The immobilizer system prevents the engine from starting by disabling the fuel system unless the proper keyless remote or proper built-in key is used. The immobilizer system consists of the:
- Immobilizer control unit-receiver
- Keyless remote
- Keyless access control unit
- Transponder in the built-in key
- Imoes unit
- PCM

Power Supply
Battery voltage is supplied at all times through fuse 7 (in the driver's under-dash fuse/relay box) to the immobilizer control unit-receiver, gauge control module, and to the Imoes unit.

Battery voltage is supplied through fuse 21 (in the driver's under-dash fuse/relay box) to the Imoes unit when the ignition switch is in the ON or START position.

Battery voltage is supplied through fuse 19 (in the driver's under-dash fuse/relay box) to the PCM when the ignition switch is in the ON or START position.

The immobilizer control unit-receiver, Imoes unit, and the PCM are all grounded at G101.

Operation
When the built-in key is inserted in the ignition switch and turned to the ON (II) position, the immobilizer control unit-receiver sends power to the transponder in the built-in key. The transponder then sends a coded signal back to the immobilizer control unit-receiver, which then sends a coded signal to the PCM and the Imoes unit. The PCM and the Imoes unit identify this coded signal and the PCM signals the fuel pump control unit to operate the fuel pump.

When using the keyless remote, the remote sends a signal to the keyless access control unit. The keyless access control unit sends a coded signal to the Imoes unit. The Imoes unit determines if the correct code is used, and if so, it signals the PCM. The PCM will then signal the fuel pump control unit to operate the fuel pump.