LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Subaru >> 2020 >> Forester Base >> Repair and Diagnosis >> Body & Frame >> Windows >> Power Window System (Diagnostics) >> Basic Diagnostic Procedure >> Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Basic Diagnostic Procedure: Procedure

NOTE: For inspection of sub-switches and the regulator & motor assembly that do not communicate with Subaru Select Monitor, refer to the "GLASS/WINDOWS/MIRRORS" article. Ref. to GLASS/WINDOWS/MIRRORS>POWER WINDOW CONTROL SWITCH . Ref. to GLASS/WINDOWS/MIRRORS>FRONT REGULATOR AND MOTOR ASSEMBLY . Ref. to GLASS/WINDOWS/MIRRORS>REAR REGULATOR AND MOTOR ASSEMBLY .
  1. PERFORM CUSTOMER INTERVIEW. 

    Ask the customer when and how the trouble occurred using the interview check list. Ref. to POWER WINDOW (DIAGNOSTICS)>CHECK LIST FOR INTERVIEW .

    Did you interview the customer?

    Yes:  Go to  2.

    No:  Perform the interview, and Go to  2.

  2. BASIC INSPECTION. 

    Perform basic inspection. Ref. to POWER WINDOW (DIAGNOSTICS)>GENERAL DESCRIPTION>INSPECTION .

    Is the check result OK?

    Yes:  Go to  3.

    No:  Repair the faulty part found in basic inspection, and Go to  3.

  3. CHECK SUBARU SELECT MONITOR COMMUNICATION. 
    1. Turn the ignition switch to OFF.
    2. Connect the Subaru Select Monitor to Data Link Connector. Ref. to COMMON (DIAG)>DATA LINK CONNECTOR .
    3. Turn the ignition switch to ON and run the Subaru Select Monitor.
    4. Select [Power Window (Switch)], [Power Window (Driver)], [Power Window (Passenger)], [Power Window (Rear Right)] and [Power Window (Rear Left)].
      NOTE: For detailed operation procedures, refer to "Help" of application.

    Is communication possible?

    Yes:  Go to  4.

    No:  Check the communication circuit. Ref. to POWER WINDOW (DIAGNOSTICS)>DIAGNOSTIC PROCEDURE FOR SUBARU SELECT MONITOR COMMUNICATION .

  4. CHECK DTC. 

    Using the Subaru Select Monitor, read the DTC in [Power Window (Switch)], [Power Window (Driver)], [Power Window (Passenger)], [Power Window (Rear Right)] and [Power Window (Rear Left)]. Ref. to POWER WINDOW (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

    • Power Window (Switch)
    • Power Window (Driver)
    • Power Window (Passenger)
    • Power Window (Rear Right)
    • Power Window (Rear Left)

    Are any DTCs displayed? (Current malfunction)

    Yes:  Record the DTC, time stamp and freeze frame data, and Go to  5.

    No:  Perform diagnosis according to the procedures in the diagnostics with phenomenon. Ref. to POWER WINDOW (DIAGNOSTICS)>DIAGNOSTICS WITH PHENOMENON .

  5. PERFORM DIAGNOSIS. 
    1. Perform the diagnosis for the displayed DTCs. Ref. to POWER WINDOW (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC)>LIST .
    2. Repair or replace the cause of trouble.
    3. Using the Subaru Select Monitor, perform the clear memory of [Power Window (Switch)], [Power Window (Driver)], [Power Window (Passenger)], [Power Window (Rear Right)] and [Power Window (Rear Left)]. Ref. to COMMON (DIAG)>CLEAR MEMORY .
      • Power Window (Switch)
      • Power Window (Driver)
      • Power Window (Passenger)
      • Power Window (Rear Right)
      • Power Window (Rear Left)
    4. Execute the inspection mode. Ref. to POWER WINDOW (DIAGNOSTICS)>INSPECTION MODE .
    5. Using the Subaru Select Monitor, read the DTC in [Power Window (Switch)], [Power Window (Driver)], [Power Window (Passenger)], [Power Window (Rear Right)] and [Power Window (Rear Left)]. Ref. to POWER WINDOW (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .
      • Power Window (Switch)
      • Power Window (Driver)
      • Power Window (Passenger)
      • Power Window (Rear Right)
      • Power Window (Rear Left)

    Are any DTCs displayed? (Current malfunction)

    Yes:  Repeat step  5 until DTC is not shown.

    No:  Finish the diagnosis.