ENGINE IMMOBILISER SYSTEM (w/o Entry and Start System) SYSTEM DESCRIPTION


  1. ENGINE IMMOBILISER SYSTEM DESCRIPTION

    The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses the transponder key ECU that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ECU sends a signal to the ECM to prohibit fuel delivery and ignition, effectively disabling the engine.

  2. FUNCTION OF MAIN COMPONENTS

    Component Outline
    Transponder key coil/amplifier When key is inserted in ignition key cylinder, key coil receives key code. Then amplifier amplifies ID code and outputs it to transponder key ECU.
    Transponder key ECU Transponder key ECU verifies transponder key ID code amplified by immobiliser coil/amplifier When key ID code is correct, ECU transmits signal to allow engine to start.
    Unlock warning switch Detects if key is in ignition key cylinder and outputs results to transponder key ECU.
    Front door courtesy light switch assembly The front door courtesy light switch (for driver side) is located on the driver door. This detects door status (open or closed) and outputs data to the transponder key ECU. This turns on when the driver door is open and turns off when the door is closed.
    ECM ECM receives ID verification results from transponder key ECU. ECM also verifies ECUs. Then judgment of whether to immobilize engine is made.

  3. SYSTEM FUNCTION


    1. When the transponder key ECU detects that the key unlock warning switch is ON, the ECU provides current to the transponder key coil and produces an electric wave. A transponder chip in the key grip receives the electric wave. Upon receiving the electric wave, the transponder chip outputs a key ID code signal. The transponder key coil receives this signal, which is amplified by the transponder key amplifier, and the signal is transmitted to the ECU.

      The ECU matches the key ID code with the vehicle ID code, which was previously registered in the ECU, and communicates the results to the ECM.

      After the identification results show that the key ID code matches the vehicle ID code and the ECU has confirmed their match, the immobiliser system does not immobilize the engine and the engine starting controls (fuel injection control and ignition control) enter standby mode.