LIGHTING SYSTEM FAIL-SAFE CHART


  1. HID Headlight System

    The light control ECU performs the following fail-safe operations when there are abnormalities in the output voltage, input voltage or light voltage.

    Item Outline

    Detection of abnormal output voltage

    (Short, open or leak)

    		 When an abnormality in output voltage is generated, headlight lighting is cancelled and remains turned off until power is turned on again (by turning the light control switch from off to head position).
    Detection of abnormal input voltage When input voltage is outside the operation range (10 to 16 V), headlight lighting is cancelled and the headlight gradually comes on again as input returns to operation voltage range. However, if the input voltage drops after lighting comes on, lighting will be maintained until voltage drops below lighting maintenance limit voltage (6 V).
    Detection of abnormal light voltage When a light voltage abnormality is detected, headlight lighting will be cancelled and remains turned off until power is turned on again (by turning the light control switch from off to head position).

  2. Automatic Headlight Beam Level Control System


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

      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. Voltage of 4.61 to 6.24 V is detected 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. Voltage of 0.26 to 4.74 V is detected
      High power source voltage Abnormal high power source 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 power source voltage (9.0 V or less) is detected. Voltage of 9.3 V or more is detected for 0.1 seconds Not illuminated
      Abnormal height control sensor signal while initialization Initialization is performed outside the valid range of the voltage for initialization. Initialization is successfully completed within the valid range of the voltage for initialization. Illuminated