LIGHTING SYSTEM FAIL-SAFE CHART


  1. HID Headlight System

    The light control ECU 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 the voltage that is input to the light control ECU is approximately 20 V or more, 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 the voltage that is input to the light control ECU is 6 V or less, the ECU stops illuminating the low beam headlights, and resumes when the voltage is 10 V or more.

    Detection of abnormal output


    • Output open

    • Short between output terminals

    • Short between output terminal and body ground

    If an abnormal condition occurs in the voltage that is output by the light control ECU, the ECU stops illuminating the low beam headlights and will maintain this state until the power is reinstated (by turning the light control switch from OFF to HEAD).
    Detection of abnormal light voltage (Low light voltage) After approximately 80 seconds since input voltage is supplied, if the light voltage is below approximately 31 V and continues for approximately 0.5 seconds, the light control ECU stops illuminating the low beam headlights and will maintain this state until the power is reinstated (by turning the light control switch from OFF to HEAD).
    Detection of abnormal light voltage (High light voltage) If the light voltage is above approximately 69 V and continues for approximately 0.5 seconds, the light control ECU stops illuminating the low beam headlights and will maintain this state until the power is reinstated (by turning the light control switch from OFF to HEAD).
  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 light control switch is turned off.

  3. 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) is detected. Normal voltage is detected 50 times 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 ignition 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 ignition voltage (9.0 V or less) is detected. Voltage of 9.3 V or more is detected for 0.1 second consecutively Not illuminated
      Vehicle speed Abnormal high speed of 180 km/h (113mph) or more is detected. Speed of less than 175 km/h (109 mph) is detected Not illuminated
      Reset while running Reset by a temporary blackout, etc. while running. Vehicle is stopped Not illuminated