Engine Immbiliser (Diagnostics - Introduction): Overview Lexus HS I

SYSTEM DESCRIPTION

1. ENGINE IMMOBILISER SYSTEM DESCRIPTION The immobiliser system is a theft deterrent system that determines whether to disable starting of the hybrid control system based on a comparison of the key ID code and vehicle pre-registered code. The immobiliser system compares the certification ECU (smart key ECU assembly) preregistered ID code with the ID of the key-embedded transponder chip. If the ID codes do not match, the immobiliser system is activated and the hybrid control system cannot be started.
2. FUNCTION OF MAIN COMPONENTS Component Outline Power switch Informs the driver of any power source or system abnormality through the illumination stage of the indicator light. Transponder key coil (built into the power switch) Receives the ID code and transmits it to the certification ECU (smart key ECU assembly) when the key battery is too weak to respond to the tuner based on signals from the room oscillators. Key Receives the signals from the oscillators and returns the ID code to the door control receiver. Certification ECU (smart key ECU assembly) Certifies the ID code received from the door control receiver. Transmits the engine immobiliser set/unset request signals. ID code box (immobiliser code ECU) Receives the immobiliser disengage signals from the certification ECU (smart key ECU assembly), certifies them, and transmits each disengage signal to the hybrid control system. Hybrid vehicle control ECU Receives the signal from the ID code box (immobiliser code ECU), and performs hybrid control system. Power management control ECU Controls ON/OFF of ACC and IG power source. Controls the power switch indicator light. Activates the IG and ACC relays. Starts the hybrid control system. Transmission control ECU Assembly Registers the ID verification code. Outputs the P state signal or not P state signal to the power management control ECU. Indoor electrical key oscillator Front, Center, Rear Transmits key detection signals within a detection area in the cabin upon receiving a transmission request signal from the certification ECU (smart key ECU assembly). A certification ECU (smart key ECU assembly) request signal is activated when the key is brought into the cabin and the power switch is pushed or brake pedal is depressed. Door control receiver Receives an ID code from a key in a detection area and transmits it to the certification ECU (smart key ECU assembly). Integration control and panel assembly Security indicator light Illuminates or flashes. Illumination is controlled by the certification ECU (smart key ECU assembly).