Engine Immobiliser System

THEFT DETERRENT / KEYLESS ENTRY: ENGINE IMMOBILISER SYSTEM: SYSTEM DIAGRAM






THEFT DETERRENT / KEYLESS ENTRY: ENGINE IMMOBILISER 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 COMPONENT





3. SYSTEM FUNCTION

(a) When the transponder key ECU detects that the unlock warning switch is ON, the transponder key ECU provides current to the antenna coil and produces a faint 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, the signal is amplified by the transponder key amplifier, and the signal is transmitted to the transponder key ECU.

(b) The transponder key ECU matches the key ID code with the vehicle ID code, which was previously registered in the transponder key 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 transponder key ECU has confirmed their match: 1) the engine immobiliser system is canceled and the engine starting controls (fuel injection control and ignition control) enter standby mode; and 2) the transponder key ECU transmits a security indicator light signal that communicates "indicator OFF" to the accessory meter (security indicator light), and the security indicator light turns off.

(c) The security indicator light pattern is as shown below (when changing from the immobiliser set status to the unset status).