Check Wiper Interlock Headlight System

Trouble symptom: 

The headlights do not go off when the wiper is deactivated, or the headlights do not turn on when the wiper is activated.

Wiring diagram: 

Front wiper and washer system Ref. to WIRING SYSTEM>FRONT WIPER AND WASHER SYSTEM>WIRING DIAGRAM>LIGHTING .

Courtesy of SUBARU OF AMERICA, INC.

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK HEADLIGHT SYSTEM  .

   Check the operation of the headlight system.

   Is the headlight system normal?

   Yes:  Go to  2.

   No:  Check and repair the headlight system. Ref. to LIGHTING SYSTEM>HEADLIGHT SYSTEM>INSPECTION>CHECK HEADLIGHT SYSTEM .

2. CHECK BODY INTEGRATED UNIT SETTING  .

   Display the data of [Illumination Sensor Setting] and [Wiper link Auto Light Setup] using Subaru

   Select Monitor. Ref. to BODY CONTROL (DIAGNOSTICS)>CUSTOMIZE .

   Is the setting in the [Support] and [ON]?

   Yes:  Go to  3.

   No:  Turn the setting to [Support] and [ON].

3. CHECK BODY INTEGRATED UNIT  .
   1. Display the [IGN voltage] data using Subaru Select Monitor. Ref. to BODY CONTROL (DIAGNOSTICS)>DATA MONITOR .
   2. Turn the ignition switch to ON.

   Is the voltage 10 - 15 V?

   Yes:  Go to  6.

   No:  Go to  4.

4. CHECK HARNESS  .

   Measure the voltage between F/B fuse No. 5 and chassis ground.

   Is the voltage 10 V or more?

   Yes:  Repair or replace the harness between the body integrated unit and the ignition switch and F/B fuse No. 5.

   No:  Go to  5.

5. CHECK CONNECTOR  .

   Check the connector or terminal of the body integrated unit for poor contact.

   Is there any fault?

   Yes:  Repair or replace the connector, harness and IG 2 relay.

   No:  Check the body integrated unit and replace it if defective.

   • Inspection: Ref. to BODY CONTROL (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .
   • Replacement: Ref. to BODY CONTROL/COMMUNICATION SYSTEM>BODY INTEGRATED UNIT .
6. CHECK BODY INTEGRATED UNIT  .

   Display the [Lighting AUTO input] data using Subaru Select Monitor. Ref. to BODY CONTROL (DIAGNOSTICS)>DATA MONITOR .

   Does the display change as [OFF] ←→ [ON] when the lighting switch is moved from the OFF position to the AUTO position?

   Yes:  Go to  11.

   No:  Go to  7.

7. CHECK BODY INTEGRATED UNIT  .

   Measure the voltage between the body integrated unit connector and chassis ground.

   Connector & terminal 

   (i83) No. 20 (+) - Chassis ground (-):

   Does the voltage change as OFF (9 to 16 V) ←→ ON (less than 1 V) when the lighting switch is moved from the OFF position to the AUTO position?

   Yes:  Check the body integrated unit and replace it if defective.

   • Inspection: Ref. to BODY CONTROL (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .
   • Replacement: Ref. to BODY CONTROL/COMMUNICATION SYSTEM>BODY INTEGRATED UNIT .

   No:  Go to  8.

8. CHECK HARNESS  .
   1. Disconnect the connectors of the combination switch (light) and the body integrated unit.
   2. Check the harness between the combination switch (light) and the body integrated unit.

      Connector & terminal For U4 and U5 

      (i131) No. 19 - (i83) No. 20:

      For C0 and C5 

      (i131) No. 18 - (i83) No. 20:

      Is the resistance less than 10 Ω?

   Yes:  Go to  9.

   No:  Repair or replace the harness between the combination switch (light) and the body integrated unit.

9. CHECK HARNESS  .

   Check the harness between the combination switch (light) connector and the chassis ground.

   Connector & terminal 

   (i131) No. 12 - Chassis ground:

   Is the resistance less than 10 Ω?

   Yes:  Go to  10.

   No:  Repair or replace the harness between the combination switch (light) and chassis ground.

10. CHECK COMBINATION SWITCH (LIGHT)  .

    Check the combination switch (light). Ref. to LIGHTING SYSTEM>COMBINATION SWITCH (LIGHT)>INSPECTION .

    Is the combination switch (light) normal when the combination switch (light) is moved to AUTO position?

    Yes:  Check the body integrated unit and replace it if defective.

    • Inspection: Ref. to BODY CONTROL (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .
    • Replacement: Ref. to BODY CONTROL/COMMUNICATION SYSTEM>BODY INTEGRATED UNIT .

    No:  Replace the combination switch (light). Ref. to LIGHTING SYSTEM>COMBINATION SWITCH (LIGHT) .

11. CHECK BODY INTEGRATED UNIT  .

    Display the [Fr wiper input] data using Subaru Select Monitor. Ref. to BODY CONTROL (DIAGNOSTICS)>DATA MONITOR .

    Does the display switch between [OFF] ←→ [ON] when the combination switch (wiper) is operated from the OFF position to INT/LO/HI?

    Yes:  Go to  16.

    No:  Go to  12.

12. CHECK FRONT RELAY CONTROL MODULE  .

    Measure the voltage between front relay control module connector and chassis ground.

    Connector & terminal 

    (B68) No. 13 (+) - Chassis ground (-):

    Does the voltage switch between OFF (less than 1 V) ←→ ON (9 to 16 V) when the combination switch (wiper) is operated from the OFF position to INT/LO/HI?

    Yes:  Check the front relay control module and replace it if defective.

    • Inspection: Ref. to FRONT RELAY CONTROL MODULE (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .
    • Replacement: Ref. to BODY CONTROL/COMMUNICATION SYSTEM>FRONT RELAY CONTROL MODULE .

    No:  Go to  13.

13. CHECK HARNESS  .
    1. Disconnect the connectors of front wiper motor and front relay control module.
    2. Check the harness between the front wiper motor and the front relay control module.

       Connector & terminal 

       (B130) No. 1 - (B68) No. 13:

    Is the resistance less than 10 Ω?

    Yes:  Go to  14.

    No:  Repair or replace the harness between the front wiper motor and the front Relay Control module.

14. CHECK HARNESS  .

    Check the harness between the front wiper motor connector and the chassis ground.

    Connector & terminal 

    (B130) No. 4 - Chassis ground:

    Is the resistance less than 10 Ω?

    Yes:  Go to  15.

    No:  Repair or replace the harness between the he front wiper motor and chassis ground.

15. CHECK FRONT WIPER MOTOR  .

    Check the continuity between front wiper motor terminals.

    Connector & terminal 

    (B130) No. 3 - (B130) No. 5:

    Is there continuity?

    Yes:  Check the front relay control module and replace it if defective.

    • Inspection: Ref. to FRONT RELAY CONTROL MODULE (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .
    • Replacement: Ref. to BODY CONTROL/COMMUNICATION SYSTEM>FRONT RELAY CONTROL MODULE .

    No:  Replace the front wiper motor. Ref. to WIPER AND WASHER SYSTEMS>FRONT WIPER MOTOR AND LINK .

16. CHECK BODY INTEGRATED UNIT  .

    Display the [Front washer switch input] data using Subaru Select Monitor. Ref. to BODY CONTROL (DIAGNOSTICS)>DATA MONITOR .

    Does the display switch between [OFF] ←→ [ON] when the front washer switch on the combination switch (wiper) is operated from the OFF position?

    Yes:  Check the connection status of the harness and connector that may have a temporary poor contact.

    No:  Go to  17.

17. CHECK BODY INTEGRATED UNIT  .

    Measure the voltage between the body integrated unit connector and chassis ground.

    Connector & terminal 

    (i83) No. 12 (+) - Chassis ground (-):

    Does the voltage switch between OFF (9 to 16 V) ←→ ON (less than 1 V) when the front washer switch on the combination switch (wiper) is operated from the OFF position?

    Yes:  Check the body integrated unit and replace it if defective.

    • Inspection: Ref. to BODY CONTROL (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .
    • Replacement: Ref. to BODY CONTROL/COMMUNICATION SYSTEM>BODY INTEGRATED UNIT .

    No:  Go to  18.

18. CHECK HARNESS  .
    1. Disconnect the connectors of the combination switch (wiper) and the body integrated unit.
    2. Check the harness between the combination switch (wiper) and the body integrated unit.

       Connector & terminal 

       (i133) No. 3 - (i83) No. 12:

    Is the resistance less than 10 Ω?

    Yes:  Go to  19.

    No:  Repair or replace the harness between the combination switch (wiper) and the body integrated unit.

19. CHECK HARNESS  .

    Check the harness between the combination switch (wiper) connector and the chassis ground.

    Connector & terminal 

    (i133) No. 2 - Chassis ground:

    Is the resistance less than 10 Ω?

    Yes:  Go to  20.

    No:  Repair or replace the harness between the combination switch (wiper) and chassis ground.

20. CHECK COMBINATION SWITCH (WIPER)  .

    Check the continuity between terminals when the front washer switch on the combination Switch (wiper) is pressed.

    Connector & terminal 

    (i133) No. 3 - (i133) No. 2:

    Is there continuity?

    Yes:  Check the body integrated unit and replace it if defective.

    • Inspection: Ref. to BODY CONTROL (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .
    • Replacement: Ref. to BODY CONTROL/COMMUNICATION SYSTEM>BODY INTEGRATED UNIT .

    No:  Replace the combination switch (wiper). Ref. to WIPER AND WASHER SYSTEMS>COMBINATION SWITCH (WIPER) .