System Description
- ENGINE IMMOBILIZER SYSTEM DESCRIPTION
The engine immobilizer system is designed to prevent the vehicle from being stolen. This system uses the transponder key ECU assembly 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.
- FUNCTION OF MAIN COMPONENTS
Component Outline Transponder key coil/amplifier When a key is inserted in the ignition key cylinder, the key coil receives the key code. Then the amplifier amplifies ID code and outputs it to the transponder key ECU assembly. Unlock warning switch assembly Detects if a key is in ignition key cylinder and outputs results to the transponder key ECU assembly. ECM The ECM receives ID verification results from the transponder key ECU assembly. The ECM also verifies the ECUs. Then judge of whether to immobilize engine. Security indicator According to the transponder key ECU assembly operation, the interior security indicator light comes on or starts blinking. - SYSTEM FUNCTION
- When the transponder key ECU assembly 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's ID code with the vehicle's ID code, which was previously registered in the ECU, and communicates the results to the ECM.
After the identification results show that the key's ID code matches the vehicle's ID code and the ECU has confirmed their match: 1) the immobilizer system does not immobilize the engine and the engine starting controls (fuel injection control and ignition control) enter standby mode; and 2) the ECU transmits a security indicator off signal to the clock. Then, the clock turns off the security indicator light.
- The security indicator pattern is as shown below (when changing from immobilizer set status to unset status):
- When the transponder key ECU assembly 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.