AUTOMATIC HEADLIGHT BEAM LEVEL CONTROL SYSTEM FAIL-SAFE CHART


  1. AUTOMATIC HEADLIGHT BEAM LEVEL CONTROL SYSTEM

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

    Item Abnormality Detection Condition Return Leveling Fail-safe Control Return Condition Multi-information Display
    Headlight swivel motor (leveling function) Communication stop

    • If the position is higher than the initial position, the headlight swivel motor (leveling function) is returned to the initial position.

    • If the position is lower than the initial position, the headlight swivel motor (leveling function) is stopped at the current position.

    		 Signals are received normally. Message displayed

    • Open circuit

    • Short circuit

    • Overheat

    • Stops the abnormal headlight swivel motor (leveling function) at the current position.

    • If the position of the normal motor is higher than the initial position, it is returned to the initial position. If the position of the normal motor is lower than the initial position, it is stopped at the current position.

    		 Engine switch is turned to on (IG) again.
    Abnormal voltage Normal value is detected. Message not displayed
    Wheel speed Abnormal wheel speed sensor

    • If either of the wheel speed signals is abnormal, control continues using the normal signal.

    • If both of the wheel speed signals are abnormal, judgment is performed as though the vehicle is stationary and control continues.

    		 When the sensor(s) return to normal. Message displayed
    Headlight control sensor sub-assembly Abnormal vehicle angle (front to rear inclination)

    • If the headlight swivel motor (leveling function) position is higher than the initial position, the headlight swivel motors (leveling function) are returned to the initial position.

    • If the headlight swivel motor (leveling function) position is lower than the initial position, the headlight swivel motors (leveling function) are stopped at the current position.

    		 Normal value is detected. Message displayed
    Power source malfunction Engine switch is turned to on (IG) again.
    Abnormal headlight control sensor sub-assembly signal Normal value is detected.
    CAN communication Main body ECU (multiplex network body ECU) communication error (headlight signal) Continues control. Signals are received normally. Message displayed
    Main body ECU (multiplex network body ECU) communication error (destination information)
    Main body ECU (multiplex network body ECU) communication error (VAST request, time stamp) Message not displayed
    ECM communication error (power source mode on IG signal) Message displayed
    Skid control ECU communication error (vehicle speed signal) Control continues. Control is performed as though the vehicle is stationary.
    Headlight leveling ECU (headlight swivel ECU assembly) Abnormal headlight leveling ECU (headlight swivel ECU assembly) Continues control. Engine switch is turned to on (IG) again. Message displayed
    Initialization of headlight control sensor sub-assembly Initialization of headlight control sensor sub-assembly not completed Adjusts the headlight swivel motor (leveling function) position to a step value so that the height will be as same as that of an unloaded vehicle. Initialization is completed Flashes (6 times)
    Abnormal headlight control sensor sub-assembly data at initialization Message displayed
    Synchronization of vehicle information Vehicle specifications have not been stored Adjusts the headlight swivel motor (leveling function) position to a step value so that the height will be as same as that of an unloaded vehicle. Synchronization is completed Flashes (0.5 Hz)
    Headlight leveling ECU (headlight swivel ECU assembly) for another vehicle specification is installed

    • If the position is higher than the initial position, the headlight swivel motor (leveling function) is returned to the initial position.

    • If the position is lower than the initial position, the headlight swivel motor (leveling function) is stopped at the current position.

    		 Headlight leveling ECU (headlight swivel ECU assembly) for current vehicle specification is installed Message displayed