Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Subaru >> 2021 >> WRX Base >> Repair and Diagnosis >> External Pages >> Different car >> Section 7 (Lighting System) >> Turn Signal Light and Hazard Light System >> Inspection >> Check Hazard Light Operation

Check Hazard Light Operation

WARNING: This page is about a different car, the 2022 Subaru WRX. However, it is still accessible from the selected car via links, so may be relevant.

Wiring diagram: 

Turn signal and hazard light system Ref. to WIRING SYSTEM>TURN SIGNAL LIGHT AND HAZARD LIGHT SYSTEM>WIRING DIAGRAM

G14612346Courtesy of SUBARU OF AMERICA, INC.
G14612347Courtesy of SUBARU OF AMERICA, INC.
NOTE:

Operate the appropriate switch according to the inspection condition. 

  1. CHECK HAZARD LIGHT OPERATION  .
    1. Turn the hazard switch to ON.
    2. Check that the hazard light operates properly.

    Does the hazard light blink?

    Yes  : The hazard light system is normal.

    No  : Go to  2.

  2. CHECK BULB  .

    Check the hazard (turn signal) light bulb.

    Is the bulb normal?

    Yes  : Go to  3.

    No  : Replace the hazard (turn signal) light bulb.

  3. CHECK DTC  .
    1. Turn the ignition switch to ON and wait for at least 10 seconds.
    2. Read the DTC of [Body Control] using the Subaru Select Monitor. Ref. to COMMON (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC)

    Is DTC displayed?

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

    No  : Go to  4.

  4. CHECK CURRENT DATA  .

    Using Subaru Select Monitor, display [Hazard switch Input] in [Data monitor] of [Body Control]. Ref. to COMMON (DIAGNOSTICS)>DATA MONITOR

    Does the display change as [OFF] ←→ [ON], when the hazard switch is turned from OFF to ON?

    Yes  : Go to  8.

    No  : Go to  5.

  5. CHECK HAZARD SWITCH  .
    1. Turn the ignition switch to OFF.
    2. Check the hazard switch. Ref. to LIGHTING SYSTEM>HAZARD SWITCH>INSPECTION 

    Is the hazard switch normal?

    Yes  : Go to  6.

    No  : Replace the hazard switch. Ref. to LIGHTING SYSTEM>HAZARD SWITCH 

  6. CHECK HARNESS  .
    1. Disconnect the connectors of body integrated unit and hazard switch.
    2. Check the harness between body integrated unit and hazard switch.

      Connector & terminal 

      (i82) No. 37 - (i137) No. 3:

    Is harness normal?

    Yes  : Go to  7.

    No  : Repair or replace the defective part.

  7. CHECK HARNESS  .

    Check the harness between the hazard switch connector and the chassis ground.

    Connector & terminal 

    (i137) No. 2 - Chassis ground:

    Is the resistance less than 10 Ω?

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

    No  : Repair or replace the defective part.

  8. CHECK CURRENT DATA  .

    Using the Subaru Select Monitor, display the following items in the [Data monitor] of [Body Control]. Ref. to COMMON (DIAGNOSTICS)>DATA MONITOR

    • [Left turn signal output]
    • [Right turn signal output]

    Does the display change as [OFF] ←→ [ON], when the hazard switch is turned from OFF to ON?

    Yes  : Go to  9.

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

  9. CHECK POWER SUPPLY  .
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector of body integrated unit.
    3. Measure the voltage between the body integrated unit connector and chassis ground.

      Connector & terminal 

      (B72) No. 4 (+) - Chassis ground (-):

    Is the voltage 9 - 16 V?

    Yes  : Go to  10.

    No  : Check the power supply circuit. Ref. to BODY CONTROL (DIAGNOSTICS)>GENERAL DESCRIPTION>INSPECTION

  10. CHECK HARNESS  .
    1. Disconnect the connectors of body integrated unit and each turn signal light.
    2. Check the harness between body integrated unit and each turn signal light.

      Connector & terminal 

      Front turn signal light RH (model without SRH) 

      (B71) No. 2 - (B121) No. 5:

      Front turn signal light LH (model without SRH) 

      (B71) No. 8 - (B122) No. 5:

      Front turn signal light RH (model with SRH) 

      (B71) No. 2 - (B121) No. 3:

      Front turn signal light LH (model with SRH) 

      (B71) No. 8 - (B122) No. 3:

      Side turn signal light RH 

      (i81) No. 5 - (Df55) No. 2:

      Side turn signal light LH 

      (i81) No. 2 - (Df56) No. 2:

      Rear turn signal light RH 

      (i81) No. 5 - (R131) No. 3:

      Rear turn signal light LH 

      (i81) No. 2 - (L131) No. 3:

    Is harness normal?

    Yes  : Go to  11.

    No  : Repair or replace the defective part.

  11. CHECK HARNESS  .

    Check the harness between each turn light connector and the chassis ground.

    Connector & terminal 

    Front turn signal light RH (model without SRH) 

    (B121) No. 6 - Chassis ground:

    Front turn signal light LH (model without SRH) 

    (B122) No. 6 - Chassis ground:

    Front turn signal light RH (model with SRH) 

    (B121) No. 4 - Chassis ground:

    Front turn signal light LH (model with SRH) 

    (B122) No. 4 - Chassis ground:

    Side turn signal light RH 

    (Df55) No. 10 - Chassis ground:

    Side turn signal light LH 

    (Df56) No. 10 - Chassis ground:

    Rear turn signal light RH 

    (R131) No. 2 - Chassis ground:

    Rear turn signal light LH 

    (L131) No. 2 - Chassis ground:

    Is the resistance less than 10 Ω?

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

    No  : Repair or replace the defective part.

scientia non olet · About Mike's Workshop Manuals