LIGHTING SYSTEM FAIL-SAFE CHART


  1. HEADLIGHT (for LED HEADLIGHT)

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

    Item Fail-safe operation
    Open in output side circuit

    • Stops illuminating the headlights

    • Keeps the headlights off until the power is reinstated (by turning the light control switch from off to the head position).
    Short between output terminal and body ground

    • Stops illuminating the headlights

    • Keeps the headlights off until the power is reinstated (by turning the light control switch from off to the head position).
    Abnormal power source voltage (17 to 23 V) is detected.

    • Stops illuminating the headlights when the input voltage becomes too high (17 to 23 V).

    • Illuminates the headlights again when the voltage returns to the operating voltage range (10 to 16 V).
    Abnormal power source voltage (7 to 10 V) is detected.

    • Limits the LED output current when the power source voltage is 7 to 10 V. (Headlights remain illuminated.)

    • Illuminates the headlights again when the voltage returns to the operating voltage range (10 to 16 V).
    Abnormal power source voltage (5.1 to 7 V) is detected.

    • Stops illuminating the headlights when the input voltage becomes too low (5.1 to 7 V).

    • Illuminates the headlights again when the voltage returns to the operating voltage range (9.2 V or more).

  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 light control switch is turned off.

  3. AUTOMATIC HEADLIGHT BEAM LEVEL CONTROL SYSTEM


    1. The headlight leveling ECU assembly operates in fail-safe mode if an abnormal condition such as those listed below has been detected, and keep the last low beam status.

      Item Abnormality Detection Condition Return Condition Warning Indicator
      Height control sensor power source voltage Abnormal height control sensor power source voltage (4.6 V or less, or 6.25 V or more) is detected. Abnormal voltage is not detected for 5 seconds consecutively Illuminated
      Height control sensor signal voltage Abnormal height control sensor signal voltage (0.25 V or less, or 4.75 V or more) is detected.
      High power source voltage Abnormal high IG supply voltage (18.5 V or more) is detected. Voltage of 17.5 V or less is detected Not illuminated
      Low power source voltage Abnormal low IG supply voltage (9.0 V or less) is detected. Voltage of 9.3 V or more is detected for 0.1 seconds consecutively Not illuminated
      Height control sensor data out of range Height control sensor data out of range when performing initialization of the headlight leveling ECU assembly Vehicle condition is proper for initialization. Illuminated
      Variation error Headlight leveling ECU assembly for another destination is installed on the vehicle Headlight leveling ECU assembly for proper destination is installed on the vehicle Illuminated