LIGHTING SYSTEM FAIL-SAFE CHART


  1. HID Headlight System

    The light control ECU sub-assembly operates in fail-safe mode if an abnormal condition such as those listed below has been detected.

    Item Outline
    Detection of abnormal input voltage (High input voltage) If voltage that is input to the light control ECU is approximately 20 V or more, the ECU stops illuminating the headlights and resumes when the voltage drops to 16 V or less.
    Detection of abnormal input voltage (Low input voltage) If voltage that is input to the light control ECU is 6 V or less, the ECU stops illuminating the low beam headlights and resumes when the voltage becomes 10 V or more.

    Detection of abnormal output


    • Open in output side circuit

    • Short between output terminals

    • Short between output terminal and body ground

    		 If an abnormal condition occurs in the voltage that is output by the light control ECU, the ECU stops illuminating the low beam headlights and will maintain this state until the power is reinstated (by turning the headlight dimmer switch from off to the head position).
    Detection of abnormal light voltage (Low light voltage) Approximately 80 seconds after input voltage is supplied, if the light voltage is below approximately 31 V for approximately 0.5 seconds, the light control ECU stops illuminating the low beam headlights and will maintain this state until the power is reinstated (by turning the headlight dimmer switch from off to the head position).
    Detection of abnormal light voltage (High light voltage) If the light voltage is above approximately 69 V for approximately 0.5 seconds, the light control ECU stops illuminating the low beam headlights and will maintain this state until the power is reinstated (by turning the headlight dimmer switch from off to the head position).

  2. Automatic Light Control System

    If the main body ECU (multiplex network body ECU) detects a malfunction in the automatic light control sensor, the main body ECU (multiplex network body ECU) performs fail-safe control to prohibit the automatic light control. If the low beam headlights and taillights are on, the lights will remain on until the headlight dimmer switch is turned off.

  3. AFS (Adaptive Front-Lighting System)

    If the headlight swivel ECU detects a malfunction in the automatic headlight beam level control system or intelligent AFS, it will take the actions indicated in the table below.

    Malfunctioning Part Detection Condition Leveling Fail-safe Control Swivel Fail-safe Control AFS OFF Indicator Light
    Headlight Swivel Motor Headlight swivel motor communication error Continues control with both headlight leveling motors lower than the current position by 0.7°. Returns both headlight swivel motors to the front-facing position. Flashes

    • Open in circuit

    • Short in circuit

    • Overheated

    • Returns normal headlight swivel motors to the front-facing position.

    • Stops the malfunctioning swivel motor at the current position.

    		 Flashes
    Voltage malfunction Off
    Gear malfunction Flashes
    Steering Angle Sensor Steering angle sensor signal malfunction Continues control. Returns both headlight swivel motors to the front-facing position. Flashes
    Speed Sensor Speed sensor signal malfunction Continues control. After 5 seconds, returns both headlight swivel motors to the front-facing position. Flashes
    Rear Height Control Sensor Rear height control sensor signal malfunction

    • Stops operation after returning the headlight motor to the initial position (system fails when the headlight motor is higher than the initial position).

    • Stops operation with the headlight motor at the current position (system fails when the headlight motor is lower than the initial position).

    		 Returns both headlight swivel motors to the front-facing position. Flashes
    Source voltage malfunction
    Headlight Leveling Motor Headlight leveling motor communication error

    Normal headlight leveling motor:


    • Stops operation after returning the headlight motor to the initial position (system fails when the headlight motor is higher than the initial position).

    • Stops operation with the headlight motor at the current position (system fails when the headlight motor is lower than the initial position).

    		 Returns both headlight swivel motors to the front-facing position. Flashes

    Headlight leveling motor malfunction


    • Open in circuit

    • Short in circuit

    • Overheated

    Normal headlight leveling motor:


    • Stops operation after returning the headlight motor to the initial position (system fails when the headlight motor is higher than the initial position).

    • Stops operation with the headlight motor at the current position (system fails when the headlight motor is lower than the initial position).

    		 Flashes
    Voltage malfunction

    Abnormal headlight leveling motor:


    • Stops operation with the headlight motor at the current position.

    		 Off
    CAN Communication System

    Communication signal malfunction

    (Main body ECU)

    		 Continues control. Returns both headlight swivel motors to the front-facing position. Flashes

    Communication signal malfunction

    (Skid control ECU)

    		 Judges that the vehicle speed is 0 km/h (0 mph) and continues control.

    Communication signal malfunction

    (Steering angle sensor)

    		 Continues control.
    Headlight Swivel ECU Vehicle specifications unconfirmed Continues control Continues control. Flashes
    Rear height control sensor initialization unconfirmed

    Both headlight leveling motors:


    • Stops operation with both motors at the same position as when the vehicle is empty.

    		 Returns both headlight swivel motors to the front-facing position. Blinks 6 times after ignition switch is turned from off to ON