High Beam Light Does Not Turn On Automatically (Mirror HBA)

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.

NOTE:

If the combination meter is defective, diagnose the combination meter first.

CAUTION:

Before performing diagnosis, refer to "CAUTION" in "General Description". Ref. to BODY CONTROL (DIAGNOSTICS)>GENERAL DESCRIPTION>CAUTION

CHECK HIGH BEAM ACTIVATION (CHECK BY MANUAL OPERATION) .
1. Turn the ignition switch to ON.
2. 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>INSPECTION
CHECK DTC .
Using the Subaru Select Monitor, read all DTCs. Ref. to LAN SYSTEM (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC)

Are any DTCs displayed?

Yes : Perform the diagnosis for the displayed DTCs. Ref. to LAN SYSTEM (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC)>LIST

No : Go to 3.
CHECK DATA MONITOR .
1. Cover the illumination sensor with a tape or the like.
2. Turn the ignition switch OFF → ON and wait for at least 15 seconds.
3. Using the Subaru Select Monitor, check the following items in the [Data Monitor] of [Body Control]. Ref. to BODY CONTROL (DIAGNOSTICS)>DATA MONITOR
  - <HBA>High Beam Assist Status
Is [Speed Under Threshold] displayed? (If the display shows [Day Detect], the ambient light sensor is not shaded enough.)

Yes : Go to 4.

No : Replace the high beam assist module. Ref. to GLASS/WINDOWS/MIRRORS>REARVIEW MIRROR
PERFORM RECOGNITION TEST .
1. Cover the illumination sensor with a tape or the like.
2. Input a vehicle speed of 60 km/h (38 MPH) or more.
3. Shade the camera.
4. Using the Subaru Select Monitor, check the following items in the [Data Monitor] of [Body Control]. Ref. to BODY CONTROL (DIAGNOSTICS)>DATA MONITOR
  - <HBA>High Beam Assist Status
  NOTE:
  Make sure to check within 60 seconds after shading the camera. (Otherwise the system will go into suspend mode after a certain period of time has elapsed with no image input to the camera, because it determines that the problem occurs due to obstacles.)
Is [Nothing Sensed] displayed?

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 high beam assist module. Ref. to GLASS/WINDOWS/MIRRORS>REARVIEW MIRROR