Land Cruiser URJ200 URJ202 GRJ200 VDJ200 - THEFT DETERRENT / KEYLESS ENTRY
ENGINE IMMOBILISER SYSTEM (w/o Entry and Start System) - SYSTEM DESCRIPTION
| ENGINE IMMOBILISER SYSTEM DESCRIPTION |
The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a 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 transponder key ECU assembly sends a signal to the ECM to prohibit fuel delivery and ignition, effectively disabling the engine.
| FUNCTION OF MAIN COMPONENTS |
| Component | Outline |
| Transponder key ECU assembly | Checks the ID code received from the transponder key amplifier and if the results match, an engine start permission signal is sent to the ECM. |
| Transponder key amplifier | When the key is inserted into the ignition key cylinder, the antenna coil receives the key code. Then the amplifier amplifies the ID code and outputs it to the transponder key ECU assembly. |
| ECM | Receives the ID verification results from the transponder key ECU assembly and verifies the ECUs. Then the judgment of whether or not to disable the engine is made. |
| Unlock warning switch assembly | Detects whether the key is in the ignition key cylinder and outputs the results to the transponder key ECU assembly. |
| SYSTEM FUNCTION |
When the transponder key ECU assembly detects that the unlock warning switch assembly is on, the transponder key ECU assembly provides current to the antenna coil and produces a weak 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, and the signal is then amplified by the transponder key amplifier and transmitted to the transponder key ECU assembly.
The transponder key ECU assembly compares the key ID code with the vehicle ID code, which was previously registered in the transponder key ECU assembly, 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 assembly has confirmed their match, the engine immobiliser system is canceled and the engine starting controls (fuel injection control and ignition control) enter standby mode.