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 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 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 power is reinstated (by turning the light control switch from off to head).
    Detection of headlight flashing If a headlight repeatedly turns off and then on and each instance of the headlight turning off and then on occurs within approximately 5 seconds of the previous instance, and if this condition continues for approximately 60 seconds, the light control ECU stops illuminating the low beam headlights and will maintain this state until power is reinstated (by turning the light control switch from off to head).
    Detection of abnormal light voltage (Low light voltage) Approximately 80 seconds after input voltage is supplied, if the light voltage is below approximately 31 V for approximately 0.5 seconds, the light control ECU stops illuminating the low beam headlights and will maintain this state until 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 for approximately 0.5 seconds, the light control ECU stops illuminating the low beam headlights and will maintain this state until power is reinstated (by turning the light control switch from off to head).

  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) 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 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
      Vehicle speed Abnormal high speed of 180 km/h (113 mph) 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

  3. Automatic Light Control Function


    1. If the main body ECU detects a malfunction in the automatic light control sensor, the main body ECU performs fail-safe control to prohibit the automatic light control.


      • If a problem occurs in the automatic light control system when the light control switch is in the AUTO position and the headlights or taillights are on, the main body ECU will keep the lights on until the light control switch is turned off or the conditions for activating the headlight auto turn off system are met.

      • If a problem occurs in the automatic light control system when the light control switch is in the AUTO position, and both headlights and taillights are off, the main body ECU will interrupt the automatic light control system operation and keep both headlights and taillights off until the output from the automatic light control sensor is determined to be normal.