LIGHTING SYSTEM


  1. FUNCTION OF MAIN COMPONENTS

    Component Function
    Headlight Leveling ECU Assembly

    • 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 Leveling Motor LH/RH

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

    • Each headlight leveling motor uses a stepper motor to precisely regulate the angle of the projector unit.
    Skid Control ECU Assembly Transmits the vehicle speed signal to the headlight leveling ECU assembly.
    Rear Height Control Sensor Sub-assembly LH Detects vehicle movement and transmits a signal to the headlight leveling ECU assembly.
    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.
    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.

  2. SYSTEM CONTROL


    1. The headlight leveling ECU assembly 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 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 operates the headlight leveling motor LH/RH in accordance with the detected change in vehicle attitude.

  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. 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 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 assembly (vehicle speed signal). Control is continued assuming vehicle speed is 0 km/h (0 mph).