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Home >> Toyota >> 2012 >> Prius Three >> Repair and Diagnosis (Single Page) >> External Pages >> Different variant/trim >> Section 26 (Auto Headlight Beam Level Control System (Plug-In) (Diagnostics - Introduction)) >> Automatic Headlight Beam Level Control System >> Fail-Safe Chart >> Fail-Safe Chart
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Fail-Safe Chart

WARNING: This page is about a different variant/trim than selected.
  1. 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