LIGHTING SYSTEM FAIL-SAFE CHART


  1. HID Headlight System


    1. Light Control ECU


      1. The light control ECU stops illuminating the HID headlights when any of the following abnormalities are detected.

        Condition Content
        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 terminals

        • 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).
        Leak between output terminal and ground point

        • 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).
        Excessively low output voltage

        • Stops illuminating the headlights when the output voltage becomes too low (31 +/- 3 V or less).

        • Keeps the headlights off until the power is reinstated (by turning the light control switch from off to the head position).
        Excessively high output voltage

        • Stops illuminating the headlights when the output voltage becomes too high (69 +/- 4 V or more).

        • Keeps the headlights off until the power is reinstated (by turning the light control switch from off to the head position).
        Excessively high input voltage

        • Stops illuminating the headlights when the input voltage becomes too high (20 +/- 3 V or more).

        • Illuminates the headlights again when the voltage returns to the operating voltage range (10 to 16 V).
        Low input voltage

        • Stops illuminating the headlights when the input voltage becomes too low (below 6 V).

        • Illuminates the headlights again when the voltage returns to the operating voltage range (10 to 16 V).

  2. 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 high 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 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 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 seconds consecutively Not illuminated
      Reset while running Reset by a temporary blackout etc. while running. Vehicle is stopped Not illuminated

  3. Automatic Light Control System

    If the main body ECU (driver side junction block assembly) detects a malfunction in the automatic light control sensor, the main body ECU (driver side junction block assembly) effects 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.

  4. Automatic High Beam System


    1. The main body ECU (driver side junction block assembly) 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
      Steering Angle Sensor Signal Malfunction Steering angle sensor malfunction is detected. Steering angle sensor malfunction is not detected, and ignition switch is turned to ON again. Flash
      Steering angle sensor zero point memory invalid is detected. Steering angle sensor zero point memory valid is detected. Not illuminated
      Steering angle sensor data continuity invalid is detected. Steering angle sensor data continuity invalid flag is detected. Not illuminated
      Speed Sensor Signal Malfunction Abnormal speed sensor signal is detected. Normal speed sensor signal is detected. Flash
      CAN Communication Signal Malfunction Normal CAN communication signal is not detected for more than 10 seconds consecutively. Normal CAN communication signal is detected. Flash
      Automatic High Beam Sensor Communication stopped for 10 seconds consecutively. Normal communication signal is detected. Flash