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Home >> Subaru >> 2023 >> Ascent Limited >> Repair and Diagnosis >> Accessories & Equipment >> Communication Devices >> Body Control System (Diagnostics) >> Diagnostics with Phenomenon >> Inspection >> The Lighting Does Not Switch From Low Beam To High Beam Automatically

The Lighting Does Not Switch From Low Beam To High Beam Automatically

Trouble symptom: 

High beam light does not turn on while the high beam assist indicator is illuminating, even when there is no object in front of the vehicle.

CAUTION: Before performing diagnosis, refer to "CAUTION" in "General Description". Ref. to BODY CONTROL (DIAGNOSTICS)>GENERAL DESCRIPTION>CAUTION .
  1. CHECK HIGH BEAM ACTIVATION (CHECK BY MANUAL OPERATION)  .

    Check for the activation of the high beam.

    • Light SW position: Second notch
    • Dimmer Hi SW: ON

    Does the high beam light come on?

    Yes:  Go to  2.

    No:  Check the headlight system. Ref. to LIGHTING SYSTEM>HEADLIGHT SYSTEM .

  2. CHECK DTC  .
    1. Turn the ignition switch to ON.
    2. Read the DTC of [EyeSight] using the Subaru Select Monitor. Ref. to EYESIGHT (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

    Are any DTCs displayed? (Current code)

    Yes:  Perform the diagnosis for the displayed DTCs.

    No:  Go to  3.

  3. CHECK "EyeSight TEMPORARY STOP INDICATOR"  .
    1. Turn the ignition switch to OFF.
    2. Turn the ignition switch to ON.
    3. Check "EyeSight temporary stop indicator". Ref. to EYESIGHT (DIAGNOSTICS)>EYESIGHT HALT CODE .

    Is "EyeSight temporary stop indicator" displayed?

    Yes:  Perform inspection according to "EyeSight temporary stop code" in "ES (DIAGNOSTICS)".

    No:  Go to  4.

  4. RECOGNITION TEST (CHECK OF NIGHT JUDGMENT)  .
    1. Set the light SW position to Auto.
    2. Set the dimmer Hi SW to ON.
    3. With the vehicle stopped, turn the ignition switch to OFF.
    4. Shade the front of the stereo camera.
      NOTE: It is recommended to perform the test under complete dark environment where all illumination is turned off and there is no windows in the room. If it is not possible to perform the test in complete dark environment, perform the test in a room where the direct sunlight is shielded and illumination is turned off, while the windshield, driver's seat, and passenger's seat are covered from outside of the vehicle with cloth etc. having high light-blocking effect.
      CAUTION: In order to avoid touching the lens of the stereo camera, do not apply light-blocking measures directly at the lens portion.
    5. Turn the ignition switch to ON.
    6. Using the Subaru Select Monitor, check [Data monitor] of [EyeSight]. Ref. to EYESIGHT (DIAGNOSTICS)>DATA MONITOR .
    • Judgment Night

    Is [Judgment Night] set to [Night]?

    Yes:  System is normal. It is considered that the conditions for the high beam activation are not satisfied enough for an environmental reason.

    No:  Replace the stereo camera. Ref. to EYESIGHT>STEREO CAMERA .