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Home >> Lexus >> 2015 >> IS 250 Base, AWD >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Headlights >> Lighting System (Ext) - Diagnostics - Introduction (1 Of 2) >> Lighting System >> System Description [04/2013 - 10/2016] >> System Description [04/2013 - 10/2016]
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System Description [04/2013 - 10/2016]

  1. AUTOMATIC LIGHT CONTROL SYSTEM 

    When the light control switch is in the AUTO position, the automatic light control system detects ambient light levels and controls the low beam headlights, clearance lights, taillights and license plate lights.

  2. LIGHT AUTO TURN-OFF SYSTEM 

    The light auto turn-off system is used to prevent the exterior lights from being accidentally left on (headlights, front fog lights, taillights, clearance lights, license plate lights and side marker lights).

    • This system has the following functions.
    Function Outline
    Delay Function The exterior lights automatically turn off after 30 seconds when all of the following conditions are met:
    • The engine switch is turned from on (IG) to off.
    • The low beam headlights are on.
    • All doors are closed after any of the doors are opened.
    Door Control Transmitter-linked Function The exterior lights turn off immediately when the delay function is active and the following condition is met:
    • The lock button on the key is pushed after all doors are locked.
    Door Open-linked The exterior lights automatically turn off immediately when all of the following conditions are met:
    • The engine switch is turned from on (IG) to off.
    • The taillights are on. (The low beam headlights are off.)
    • The driver door is opened.
  3. DAYTIME RUNNING LIGHT SYSTEM 

    The daytime running light system is designed to automatically illuminate the daytime running lights (high-intensity clearance lights) during the daytime to make the vehicle more visible to other vehicles.

    • This system is controlled by the main body ECU (multiplex network body ECU).
    • There are 2 LED type clearance light circuits in each clearance light assembly. One is for a conventional low-intensity clearance light that illuminates with the taillights, and the other is for the high-intensity clearance light that is used for the DRL system.
    • This system is enabled when the following conditions are met:
      • Engine switch is on (IG).
      • Engine speed signal is input (engine running).
      • Light control switch is in the off, tail or AUTO position (and the low beam headlights are not turned on via the automatic light control system). (w/o DRL OFF Switch)
      • Light control switch is in the tail or AUTO position (and the low beam headlights are not turned on via the automatic light control system). (w/ DRL OFF Switch)
      • Parking brake switch is off.
  4. HID HEADLIGHT SYSTEM 

    The High Intensity Discharge (HID) headlight system uses a discharge bulb as its light source for the low beam and high beam. Discharge bulbs are superior to halogen bulbs.

    • Discharge bulbs have the following features:
      • The light emitted by the bulb is close in color to sunlight. The light shines ahead over a broader area and further forward, increasing the area visible to the driver.
      • Less power is consumed.
    • This system consists of the discharge bulbs and light control ECUs.
    • The light control ECU transforms voltage that is received from the battery to high voltage of up to 30000 V and applies it to the discharge bulbs in order to illuminate them.
  5. WELCOME LIGHT ILLUMINATION CONTROL 
    1. When a wireless door unlock operation or entry door unlock operation is performed at nighttime, the clearance lights illuminate for 15 seconds.
  6. DOOR MIRROR FOOT LIGHT SYSTEM 
    1. General
      • The door mirror foot light system consists primarily of the fade-in/fade-out function and timer illumination function.
      • This control is controlled by the outer mirror control ECU assembly for each mirror and main body ECU (multiplex network body ECU). The main body ECU (multiplex network body ECU) sends door mirror foot light on/off demand signals to the outer mirror control ECU assembly. According to various information, the outer mirror control ECU assembly performs fade-in/fade-out control of the door mirror foot lights.
    2. The door mirror foot light system has the following control functions:
      Function Outline
      Actuation Area-linked When all of the following conditions are met, the lights that operate turn on:
      • The engine switch is off.
      • All doors are closed.
      • A key is detected in the actuation area.
      When the following condition is met, the lights that operate turn off:
      • A key is not detected in the actuation area.
      Door Unlock-linked When all of the following conditions are met, the lights that operate turn on:
      • The engine switch is off.
      • All doors are closed.
      • Any door is unlocked when all doors are locked.
      Door Lock-linked When either of the following conditions is met, the lights that operate turn off:
      • All doors are locked when all doors are closed and any door is unlocked.
      • All doors are locked again when all doors are closed and locked.
      Engine Switch-linked When the following condition is met, the lights that operate turn off:
      • The engine switch is on (IG).
      Delay When approximately 15 seconds elapse after any of the following conditions are met, the lights that operate turn off:
      • An actuation area-linked function is used.
      • The door unlock-linked function is active.
      • Any door is opened and then closed.