Section 170 (Engine Immobilizer Systems): Operation

WARNING: This page is about a different car, the 2002 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.

Transponder chip is incorporated into top of ignition key. When ignition key is inserted into ignition lock cylinder, the Engine Control Module (ECM) instructs transponder key coil on ignition lock cylinder to supply an electromagnetic energy that enables transponder chip to transmit an ignition key identification code signal.

Transponder key amplifier then amplifies ignition key identification code signal and delivers ignition key identification code signal to ECM. The ECM compares received ignition key identification code signal to identification code stored in ECM memory. If ignition key identification code and identification code in ECM memory match, ECM will allow fuel injector operation and ignition system operation. If ignition key identification code and identification code in ECM memory do not match, ECM will not allow fuel injector operation and ignition system operation.

Engine immobilizer system is set each time ignition key is removed from ignition lock cylinder. When engine immobilizer system is set, SECURITY indicator light will flash to indicate system is set. SECURITY indicator light is located just above fuel gauge on instrument cluster. See Figure. For information on programming of ECM and ignition key identification key codes, see PROGRAMMING . If a problem exists in engine immobilizer system, a Diagnostic Trouble Code (DTC) may be stored in ECM, but the Malfunction Indicator Light (MIL) will not illuminate. MIL is displayed as an engine icon near the speedometer on the instrument cluster and may also be referred to as CHECK ENGINE light.