LIGHTING SYSTEM FAIL-SAFE CHART


  1. HID Headlight System

    The headlight 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 headlight light control ECU is approximately 20 V or higher, 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 headlight 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 higher.

    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 headlight 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 headlight 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 headlight 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 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. AUTOMATIC HIGH BEAM SYSTEM (w/ Automatic High Beam System)


    1. The automatic high beam system operates in fail-safe mode if an abnormal condition, such as those listed below, has been detected.

      Item Abnormality Detection Condition Return Condition
      Automatic High Beam Sensor Abnormal communication signal is detected. Normal communication signal is detected.
      Speed Sensor Signal Malfunction Abnormal speed sensor signal is detected. Normal speed sensor signal is detected.
      CAN Communication Signal Malfunction Abnormal CAN communication signal is detected. Normal CAN communication signal is detected.

  4. Automatic Headlight Beam Level Control System (w/o AFS)

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

    Malfunctioning Part Detection Condition Leveling Fail-safe Control Return Condition Warning Light
    Headlight Swivel Motor (Leveling Portion) Headlight swivel motor (leveling portion) communication error

    • When higher than the initial position, the motor returns to the initial position.

    • When lower than the initial position, the motor remains in that position.

    		 Normal communication signal is detected. Flashes

    • Open in circuit

    • Short in circuit

    • Overheated

    • When the normally functioning headlight swivel motor is higher than the initial position, the motor returns to the initial position and when lower than the initial position, the motor remains in that position.

    • The malfunctioning headlight swivel motor remains in the current position.

    		 Engine switch is turned on (IG) again.
    Voltage malfunction Normal condition is detected. Off
    Speed Sensor Speed sensor signal malfunction

    • When one side is malfunctioning, control continues using the vehicle speed from the normally functioning sensor.

    • When both are malfunctioning, controls continues as if the vehicle were stopped.

    		 The sensor malfunction is resolved. Flashes
    Rear Height Control Sensor LH Source voltage malfunction

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

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

    		 Engine switch is turned on (IG) again. Flashes
    Rear height control sensor LH signal malfunction Normal condition is detected.
    Headlight Swivel ECU ROM malfunction/ROM communication malfunction (DTC/FFD portion) Continues control. Engine switch is turned on (IG) again. Flashes
    ROM malfunction/ROM communication malfunction (except DTC/FFD portion)

    • When higher than the initial position, the motor returns to the initial position.

    • When lower than the initial position, the motor remains in that position.
    CAN Communication System Main body ECU communication signal malfunction (headlight information) Continues control. Normal communication signal is detected. Flashes
    Main body ECU communication signal malfunction (destination information and time stamp information)
    Main body ECU communication signal malfunction (engine specifications and engine starting information)
    Skid control ECU communication signal malfunction (vehicle speed information) Judges that the vehicle speed is 0 km/h (0 mph) and continues control.

  5. AFS (Adaptive Front-Lighting System) (w/ AFS)

    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 Return Condition Warning Light
    Headlight Swivel Motor Headlight swivel motor communication error Continues control with both headlight swivel motors (leveling portion) lower than the current position by 0.65°. Returns both headlight swivel motors to the front-facing position. Normal communication signal is detected. Flashes

    • Open in circuit

    • Short in circuit

    • Overheated

    • Gear malfunction

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

    • Stops the malfunctioning swivel motor at the current position.

    		 Engine switch is turned on (IG) again.
    Voltage malfunction Normal condition is detected. Off
    Headlight Swivel Motor (Leveling Portion) Headlight swivel motor (leveling portion) communication error

    • When higher than the initial position, the motor returns to the initial position.

    • When lower than the initial position, the motor remains in that position.

    		 Returns both headlight swivel motors to the front-facing position. Normal communication signal is detected. Flashes

    • Open in circuit

    • Short in circuit

    • Overheated

    • When the normally functioning headlight swivel motor is higher than the initial position, the motor returns to the initial position and when lower than the initial position, the motor remains in that position.

    • The malfunctioning headlight swivel motor remains in the current position.

    		 Engine switch is turned on (IG) again.
    Voltage malfunction Normal condition is detected. Off
    Steering Angle Sensor Steering angle sensor signal malfunction Continues control. Returns both headlight swivel motors to the front-facing position. Engine switch is turned on (IG) again. Flashes
    VGRS VGRS sensor signal malfunction Continues control. Returns both headlight swivel motors to the front-facing position. Engine switch is turned on (IG) again. Flashes
    DRS DRS malfunction Continues control. Returns both headlight swivel motors to the front-facing position. Engine switch is turned on (IG) again. Flashes
    Speed Sensor Speed sensor signal malfunction

    • When one side is malfunctioning, control continues using the vehicle speed from the normally functioning sensor.

    • When both are malfunctioning, controls continues as if the vehicle were stopped.

    		 After control continues using the vehicle speed detected before the malfunction, the headlight swivel motors return to the front-facing position. The sensor malfunction is resolved. Flashes
    Rear Height Control Sensor LH Source voltage malfunction

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

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

    		 Returns both headlight swivel motors to the front-facing position. Engine switch is turned on (IG) again. Flashes
    Rear height control sensor LH signal malfunction Normal condition is detected.
    Headlight Swivel ECU ROM malfunction/ROM communication malfunction (DTC/FFD portion) Continues control. Continues control. Engine switch is turned on (IG) again. Flashes
    ROM malfunction/ROM communication malfunction (except DTC/FFD portion)

    • When higher than the initial position, the motor returns to the initial position.

    • When lower than the initial position, the motor remains in that position.

    		 Returns both headlight swivel motors to the front-facing position.
    CAN Communication System Main body ECU communication signal malfunction (headlight information) Continues control. Returns both headlight swivel motors to the front-facing position. Normal communication signal is detected. Flashes
    Main body ECU communication signal malfunction (destination information and time stamp information) Continues control.
    Main body ECU communication signal malfunction (engine specifications and engine starting information)
    Main body ECU communication signal malfunction (shift position information) Returns both headlight swivel motors to the front-facing position.
    Skid control ECU communication signal malfunction (vehicle speed information) Judges that the vehicle speed is 0 km/h (0 mph) and continues control.
    Steering angle sensor communication signal malfunction (steering angle information) Continues control.
    Front steering control ECU communication signal malfunction (VGRS angle information)
    Rear steering control ECU communication signal malfunction (DRS actual steering angle information)