AUTOMATIC HEADLIGHT BEAM LEVEL CONTROL SYSTEM(except Sedan) FAIL-SAFE CHART


  1. Automatic Headlight Beam Level Control System

    If the 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 Fail-safe Control Return Condition Warning Message
    Headlight leveling motor Communication stop

    • If the position is higher than the initial position, the headlight leveling motor is returned to the initial position.

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

    		 Signals are received normally. Illuminate

    • Open circuit

    • Short circuit

    • Overheat

    • Stops the abnormal headlight leveling motor 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.

    		 Ignition switch is turned to ON again.
    Abnormal voltage Normal value is detected. Does not illuminate
    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. Illuminate
    Rear height control sensor sub-assembly Abnormal vehicle angle (front to rear inclination)

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

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

    		 Normal value is detected. Illuminate
    Power source malfunction Ignition switch is turned to ON again.
    Abnormal rear height 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. Illuminate
    Main body ECU (multiplex network body ECU) communication error (destination information, VAST request, time stamp)
    ECM communication error (power source mode on IG signal)
    Skid control ECU communication error (vehicle speed signal) Control continues. Control is performed as though the vehicle is stationary.
    Headlight swivel ECU assembly Abnormal headlight swivel ECU assembly Continues control. Ignition switch is turned to ON again. Illuminate
    Initialization of rear height control sensor sub-assembly Initialization of rear height control sensor sub-assembly not completed Adjusts the headlight leveling motor position to a step value so that the height will be as same as that of an unloaded vehicle. Initialization is completed Flashes (2Hz 6 times)
    Abnormal rear height control sensor sub-assembly data at initialization Illuminate
    Synchronization of vehicle information Vehicle specifications have not been stored Adjusts the headlight leveling motor position to a step value so that the height will be as same as that of an unloaded vehicle. Synchronization is completed Illuminate
    Headlight swivel ECU assembly for another vehicle specification is installed

    • If the position is higher than the initial position, the headlight leveling motor is returned to the initial position.

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

    		 Headlight swivel ECU assembly for current vehicle specification is installed