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System Description

WARNING: This page is about a different car, the 2007 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.
  1. FUNCTION OF MAIN COMPONENTS 
    FUNCTION OF MAIN COMPONENTS

    Components Function
    Automatic light control sensor Detects brightness around and sends information to driver side junction block ECU
    Hazard warning switch Its on or off state is sent to driver side junction block ECU
    Stop light switch Sends brake pedal state to driver side junction block ECU
    Ignition switch Its ON / ACC / OFF state is sent to driver side junction block ECU
    Door courtesy switch Detects door open / closed state and sends information to respective door ECU
    PNP switch Detects shift position and sends information to ECM
    Parking brake switch Detects parking brake state and sends information to skid control ECU
    Headlight unit Moves headlights up and down according to information from AFS ECU
    Height control sensor Detects vehicle height and sends corresponding information to AFS ECU
  2. OPERATION DESCRIPTION 
    1. Manual lighting system
      1. The manual lighting system is controlled by the front light ECU based on the signals listed below.
        OPERATION DESCRIPTION - MANUAL LIGHTING SYSTEM

        Received Sends ON / OFF operation
        Clearance light switch signal Clearance light ON demand signal Clearance light
        High beam light switch signal High beam ON signal Headlight (high)
        Headlight switch signal Headlight ON demand signal Headlight (low)
        Taillight switch signal Front fog light switch signal Front fog light ON signal Front fog light Front side make light
    2. Automatic light control system
      1. The automatic light system is controlled by the driver side junction block ECU based on the signals listed below.
        OPERATION DESCRIPTION - AUTOMATIC LIGHT CONTROL SYSTEM

        Received Sends ON / OFF operation
        Light switch auto switch signal Headlight ON demand signal (low) Headlight
        Clearance light
        License plate light
        Light control switch signal High beam ON signal / Taillight ON demand signal Front side marker light
        Taillight
    3. Turn signal light system
      1. The turn signal light system is controlled by the driver side junction block ECU based on the signals listed below.
        OPERATION DESCRIPTION - TURN SIGNAL LIGHT SYSTEM

        Received Sends ON / OFF operation
        Right turn signal or hazard warning signal Right turn ON demand signal Right turn signal light
        Left turn signal or hazard warning signal Left turn ON demand signal Left turn signal light
    4. Daytime running light system
      1. The daytime running light system is controlled by the driver side junction block ECU based on the signals listed below.
        OPERATION DESCRIPTION - DAYTIME RUNNING LIGHT SYSTEM

        Received Sends ON / OFF operation
        Headlight switch signal
        Light switch auto signal light control switch signal
        Shift position D signal
        Parking brake switch signal        		 Daytime running light ON demand signal Headlight (high)
    5. Stop light system
      1. The stop light system is controlled by the luggage room junction block ECU based on the signals listed below.
        OPERATION DESCRIPTION - STOP LIGHT SYSTEM

        Received Sends ON / OFF operation
        Stop light signal
        Brake control signal        		 Stop light ON demand signal Stop light Center stop light
    6. Back-up light system
      1. The back-up light system is controlled by the luggage room junction block ECU based on the signals listed below.
        OPERATION DESCRIPTION - BACK-UP LIGHT SYSTEM

        Received Sends ON / OFF operation
        Shift position R signal Back-up light ON demand signal Back-up light
    7. Illumination entry system
      1. The illumination entry system is controlled by the passenger side junction block ECU based on the signals listed below.
        OPERATION DESCRIPTION - ILLUMINATION ENTRY SYSTEM

        Received Sends ON / OFF operation
        Driver side door courtesy light switch signal
        Passenger side door courtesy light switch signal
        Driver door lock signal
        Passenger door lock signal
        Ignition switch signal        		 Illumination ON demand signal Ignition key cylinder light
        Map light
    8. Stop light system
      1. The step light system is controlled by the passenger side junction block ECU based on the signals listed below.
        OPERATION DESCRIPTION - STOP LIGHT SYSTEM

        Received Sends ON / OFF operation
        Driver side door courtesy light switch signal
        Passenger side door courtesy light switch signal
        Driver door lock signal
        Passenger door lock signal
        Ignition switch signal        		 Stop light ON demand signal Stop light
    9. Buckle illumination system
      1. The buckle illumination system is controlled by the driver side junction block ECU based on the signals listed below.
        OPERATION DESCRIPTION - BUCKLE ILLUMINATION SYSTEM

        Received Sends ON / OFF operation
        Driver side door courtesy light switch signal
        Passenger side door courtesy light switch signal
        Driver door lock signal
        Passenger door lock signal
        Ignition switch signal        		 Buckle illumination ON demand signal Buckle illumination
    10. Door courtesy light system
      1. The courtesy light system is controlled by the driver side junction block ECU based on the signals listed below.
        OPERATION DESCRIPTION - DOOR COURTESY LIGHT SYSTEM

        Received Sends ON / OFF operation
        Driver side door courtesy light switch signal
        Passenger side door courtesy light switch signal        		 Courtesy light ON demand signal Courtesy light
    11. AFS
      1. The AFS is controlled by the AFS ECU based on the signals listed below.
        OPERATION DESCRIPTION - AFS

        Received Sends ON / OFF operation
        Headlight signal
        Steering sensor signal
        Vehicle speed signal
        Height control sensor signal        		 Headlight swivel motor operation demand signal
        Headlight beam level control actuator operation demand signal        		 Headlight swivel motor
        Headlight beam level control actuator
        AFS OFF switch signal AFS OFF indicator light ON demand signal AFS OFF indicator light
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