LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Subaru >> 2021 >> Ascent Base >> Repair and Diagnosis >> Transmission >> Automatic Trans >> Automatic Transaxle (Diagnostics) >> AWD Warning Light Display >> Inspection
April 5, 2026: LEMON Manuals is launched! Read the announcement.

AWD Warning Light Display: Inspection

Diagnosis: 

Trouble symptom: 

  1. CHECK TCM  .

    Using the Subaru Select Monitor, read DTC of [transmission]. Ref. to TRANSMISSION (DIAGNOSTICS)>Diagnostic Trouble Code (DTC) .

    Is DTC U0155 or U0423 displayed?

    Yes  : Perform the self-diagnosis of combination meter.

    No  : Go to  2.

  2. CHECK TCM  .

    Using the Subaru Select Monitor, read DTC of [transmission]. Ref. to TRANSMISSION (DIAGNOSTICS)>Diagnostic Trouble Code (DTC) .

    Are DTCs other than U0155 and U0423 displayed?

    Yes  : Perform the diagnosis according to the DTC. Ref. to TRANSMISSION (DIAGNOSTICS)>Diagnostic Trouble Code (DTC)>LIST .

    No  : Go to  3.

  3. CHECK COMBINATION METER  .

    Using the Subaru Select Monitor, read DTC of [combination meter]. Ref. to COMBINATION METER (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

    Are any DTCs displayed?

    Yes  : Perform the diagnosis according to the DTC. Ref. to COMBINATION METER (DIAGNOSTICS)>Diagnostic Trouble Code (DTC)>LIST .

    No  : Go to  4.

  4. CHECK AWD LIGHT  .

    Turn the ignition switch to ON.

    Does AWD light illuminate and then go off in 2 seconds?

    Yes  : Go to  5.

    No  : Perform the self-diagnosis of combination meter. Ref. to INSTRUMENTATION/DRIVER INFO>Combination Meter System>OPERATION>SELF-DIAGNOSIS DISPLAY MODE .

  5. CHECK AWD LIGHT  .

    Start the engine.

    Does the AWD light go off?

    Yes  : Current condition is normal. Go back to Basic Diagnostic Procedure. Ref. to TRANSMISSION (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .

    No  : Go to  6.

  6. CHECK DTC  .

    Using the Subaru Select Monitor, read DTC of [transmission]. Ref. to TRANSMISSION (DIAGNOSTICS)>Diagnostic Trouble Code (DTC) .

    Are any DTCs displayed?

    Yes  : Perform the diagnosis according to the DTC. Ref. to TRANSMISSION (DIAGNOSTICS)>Diagnostic Trouble Code (DTC)>LIST .

    No  : Go to  7.

  7. CHECK AWD LIGHT  .

    Check the display of AWD light after engine start.

    Is AWD light illuminating?

    Yes  : Go to  9.

    No  : Go to  8.

  8. CHECK AWD LIGHT  .

    Check the display of AWD light after engine start.

    Is AWD light blinking at 2 Hz?

    Yes  : Go to  10.

    No  : Go to  11.

  9. CHECK AWD ON/OFF SWITCHING FUNCTION  .

    Using the Subaru Select Monitor, select [AWD ON/OFF switching mode] on the [Work Support] screen, and check the current mode. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION (TR690)>AWD ON/OFF SWITCHING MODE .

    Is the message [At present, the vehicle is in AWD. Switch to FF?] displayed?

    Yes  : Go to  11.

    No  : If the message [At present, the vehicle is in FF. Switch to AWD?] is displayed, select "OK", and switch to AWD mode.

  10. CHECK REAR DIFFERENTIAL  .

    Using the Subaru Select Monitor, select and check [Rear differential inspection mode] on the [Work Support] display. Ref. to DIFFERENTIALS>REAR DIFFERENTIAL INSPECTION MODE .

    Does AWD light go off after inspection is finished normally?

    Yes  : Current condition is normal. Go back to Basic Diagnostic Procedure. Ref. to TRANSMISSION (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .

    No  : Go to  11.

  11. CHECK COMBINATION METER  .

    Perform the self-diagnosis of combination meter. Ref. to INSTRUMENTATION/DRIVER INFO>Combination Meter System>OPERATION>SELF-DIAGNOSIS DISPLAY MODE .

    Is the check result OK?

    Yes  : Replace the TCM. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION (TR690)>TRANSMISSION CONTROL MODULE (TCM) .

    No  : Repair or replace the combination meter. Ref. to INSTRUMENTATION/DRIVER INFO>COMBINATION METER .