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Home >> Toyota >> 2014 >> Prius Four >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 27 (Automatic Beam Level Control System (Diagnostics - Introduction) (Plug-In)) >> Automatic Headlight Beam Level Control System >> System Description [10/2013 - ] >> System Description [10/2013 - ]
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System Description [10/2013 - ]

WARNING: This page is about a different variant/trim than selected.
  1. AUTOMATIC HEADLIGHT BEAM LEVEL CONTROL SYSTEM 
    1. General
      • This system maintains the low beam headlights at a constant level while the vehicle is stopping.
      • This system is controlled by the headlight leveling ECU assembly. The headlight leveling ECU assembly detects the vehicle posture via the rear height control sensor sub-assembly, and detects the vehicle speed via the combination meter assembly. The headlight leveling ECU assembly controls each headlight leveling motor based on these pieces of information in order to change the headlight reflector angle.
      NOTE:
      • Initialize the rear height control sensor sub-assembly signal after the vehicle height changes due to replacement of the suspension or after operations as reinstallation or replacement of the rear height control sensor sub-assembly.
      • When the headlight leveling ECU assembly is replaced, initialization is also necessary.
    2. Function of Main Components
      Component Outline
      Rear Height Control Sensor Sub-assembly Detects vehicle height.
      Combination Meter Assembly
      • Outputs the vehicle speed signal to the headlight leveling ECU assembly.
      • The headlight beam level control system indicator light in the combination meter illuminates for 3 seconds and then goes off when the power switch is turned on (IG) (bulb check function).
      • The headlight beam level control system indicator light in the combination meter illuminates to alert the driver when a malfunction in this system is detected.
      Headlight Leveling Motor Based on the signals received from the headlight leveling ECU assembly, each motor moves the reflector in the headlight to vary its low beam.
      Headlight Leveling ECU Assembly
      • Based on the signals that are transmitted by the rear height control sensor sub-assembly and combination meter assembly, the headlight leveling ECU assembly detects the amount of variance of the vehicle posture while the vehicle is stopping.
      • Based on the detected value, the headlight leveling ECU assembly outputs control signals to the headlight leveling motor.
      • The headlight leveling ECU assembly turns on the headlight beam level control system indicator light for 3 seconds when the power switch is turned on (IG) (bulb check function).
      • The headlight leveling ECU assembly turns on the headlight beam level control system indicator light to alert the driver when a malfunction in this system is detected.