LIGHTING SYSTEM


  1. FUNCTION OF MAIN COMPONENTS

    Component Function
    Headlight Leveling ECU Assembly*1

    • Detects changes of vehicle movement based on the signals from the rear height control sensor sub-assembly LH and vehicle speed signal.

    • Outputs control signals to the headlight leveling motors based on the detected value.

    • Provides initial set control and a fail-safe function.
    Headlight Light Control ECU Sub-assembly LH*2

    • Controls the automatic headlight beam level control system.

    • Detects the vehicle posture and vehicle driving conditions based on the rear height control sensor sub-assembly LH and skid control ECU to control the headlight leveling motor LH. When a malfunction is detected in the system, sends an automatic headlight beam level control warning light on request signal to the combination meter assembly.
    Headlight Light Control ECU Sub-assembly RH*2 Controls the headlight leveling motor RH according to control signals from the headlight light control ECU sub-assembly LH.
    Headlight Leveling Motor LH/RH

    • Based on the signals received from the headlight leveling ECU assembly, each headlight leveling motor moves the projector unit in the headlight to vary its angle.*1

    • Moves the low beam headlights vertically and controls the beam axis direction according to control signals from the headlight light control ECU assembly LH/RH.*2

    Brake Actuator Assembly


    • Skid Control ECU

    		 Transmits the vehicle speed signal to the headlight leveling ECU assembly*1 or headlight light control ECU sub-assembly LH*2.
    Rear Height Control Sensor Sub-assembly LH Detects vehicle movement and transmits a signal to the headlight leveling ECU assembly*1 or headlight light control ECU sub-assembly LH*2.
    Headlight Dimmer Switch Assembly Transmits a light control signal to the main body ECU (multiplex network body ECU).
    Main Body ECU (Multiplex Network Body ECU) Receives a light control signal and transmits it to the headlight leveling ECU assembly*1 or headlight control ECU sub-assembly LH*2.
    Combination Meter Assembly Flashes the headlight leveling warning light, displays a warning message on the multi-information display and sounds the buzzer to inform the driver when the headlight leveling ECU assembly detects a malfunction in this system.

    *1: Models with single beam headlight

    *2: Models with triple beam headlight

  2. SYSTEM CONTROL


    1. The headlight leveling ECU assembly*1 or headlight light control ECU sub-assembly LH*2 receives vehicle height change signals sent from the rear height control sensor sub-assembly LH and calculates the changes in the pitch angle of the vehicle. The headlight leveling ECU assembly*1 or headlight light control ECU sub-assembly LH/RH*2 drives the headlight leveling motor LH/RH in accordance with the change.

      Control Mode Details
      While Stopped If the vehicle attitude is stable for approximately 3 seconds with the headlights on while stopped, the headlight leveling ECU assembly*1 or headlight light control ECU sub-assembly LH/RH*2 operates the headlight leveling motor LH/RH in accordance with the detected change in vehicle attitude.

      *1: Models with single beam headlight

      *2: Models with triple beam headlight

  3. FUNCTION


    1. The rear height control sensor sub-assembly LH detects the changes in vehicles rear ride height due to cargo loads etc., and operates the headlight leveling motor RH/LH in accordance with the changes, keeping the headlight axes at a constant angle.

  4. FAIL-SAFE


    1. Models with single beam headlight


      1. When the headlight leveling ECU assembly detects a malfunction in the system, the system enters fail-safe mode as follows.

        Malfunctioning Parts Malfunction Detection Conditions Performed Control
        Excessively high input voltage The input voltage of the headlight leveling ECU assembly becomes 18.5 V or more. Control signal output to the headlight leveling motor RH/LH is stopped.
        Low input voltage The input voltage of the headlight leveling ECU assembly becomes 9 V or less.
        Rear height control sensor sub-assembly LH high input voltage The input voltage of the rear height control sensor sub-assembly LH becomes 6.25 V or more.
        Rear height control sensor sub-assembly LH low input voltage The input voltage of the rear height control sensor sub-assembly LH becomes 4.6 V or less.
        Rear height control sensor sub-assembly LH signal malfunction The signal voltage of the rear height control sensor sub-assembly LH becomes 4.75 V or more.
        The signal voltage of the rear height control sensor sub-assembly LH becomes 0.25 V or less.
        Headlight leveling ECU assembly malfunction The headlight leveling ECU assembly has a malfunction.
        CAN malfunction There is a malfunction in the data communication with the main body ECU (multiplex network body ECU) (headlight information). Control is continued.
        There is a malfunction in the data communication with the skid control ECU (brake actuator assembly) (vehicle speed signal). Control is continued assuming vehicle speed is 0 km/h (0 mph).

    2. Models with triple beam headlight


      1. If the headlight light control ECU sub-assembly detects a malfunction in the automatic headlight beam level control system, the headlight light control ECU sub-assembly performs the fail-safe operation. For details, refer to the Repair Manual.