Brake Warning Light Does Not Go Off

Detecting condition: 

• Brake warning light circuit is shorted.
• Defective sensor/connector
• Defective CAN communication

Trouble symptom: 

After starting the engine, the brake warning light does not go off even though the parking lever is released.

Wiring diagram: 

• Models without EyeSight

  Parking brake/brake fluid level warning light system. Refer to WIRING SYSTEM>PARKING BRAKE/BRAKE FLUID LEVEL WARNING LIGHT SYSTEM>WIRING DIAGRAM>WITHOUT EYESIGHT .

  Courtesy of SUBARU OF AMERICA, INC.

1. CHECK INSTALLATION OF VDC Control Module & H/U CONNECTOR. 
   1. Turn the ignition switch to OFF.
   2. Check that the VDC Control Module & H/U connector is inserted until it is locked by clamp.

   Is the connector firmly inserted?

   Yes:  Go to  2.

   No:  Insert the VDC Control Module & H/U connector until it is locked by clamp.

2. READ DTC. 

   Read the DTC. Refer to VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)>READ DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC displayed?

   Yes:  Perform the diagnosis according to DTC. Refer to VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)>LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .

   No:  Go to  3.

3. CHECK LAN SYSTEM. 

   Perform the diagnosis for LAN system. Refer to LAN SYSTEM (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .

   Is there any fault in LAN system?

   Yes:  Perform the diagnosis according to DTC for LAN system. Refer to LAN SYSTEM (DIAGNOSTICS)>LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .

   No:  Go to  4.

4. CHECK BRAKE FLUID AMOUNT. 

   Check the amount of brake fluid in the reservoir tank of master cylinder.

   Does the level of the brake fluid amount fall between the lines of "MAX" and "MIN"?

   Yes:  Go to  5.

   No:  Replenish brake fluid to the specified value.

5. CHECK BRAKE FLUID LEVEL SWITCH. 
   1. Turn the ignition switch to OFF.
   2. Disconnect the level switch connector (B16) from master cylinder.
   3. Measure the resistance of master cylinder terminals.

      Terminals 

      No. 1 - No. 2:

   Is the resistance 1 Ω or more?

   Yes:  Go to  6.

   No:  Replace the master cylinder. Refer to BRAKE>MASTER CYLINDER .

6. CHECK GROUND SHORT OF HARNESS. 
   1. Disconnect the connector (i10) from combination meter.
   2. Measure the resistance between combination meter connector and chassis ground.

      Connector & terminal 

      (i10) No. 23 - Chassis ground:

   Is the resistance 1 Ω or more?

   Yes:  Go to  7.

   No:  Repair the harness between combination meter and brake fluid level switch.

7. CHECK PARKING BRAKE SWITCH. 
   1. Disconnect the connector (R4) from parking brake switch.
   2. Release the parking brake.
   3. Measure the resistance between parking brake switch terminal and chassis ground.

   Is the resistance 1 Ω or more?

   Yes:  Go to  8.

   No:  Replace the parking brake switch.

8. CHECK GROUND SHORT OF HARNESS. 
   1. Disconnect the connector (i84) from body integrated unit.
   2. Measure the resistance between body integrated unit connector and chassis ground.

      Connector & terminal 

      (i84) No. 32 - Chassis ground:

   Is the resistance 1 Ω or more?

   Yes:  Go to  9.

   No:  Repair the harness between body integrated unit and parking brake switch.

9. CHECK POOR CONTACT OF CONNECTOR. 

   Check for poor contact of all connectors.

   Is there poor contact?

   Yes:  Repair the connector.

   No:  Go to  10.

10. CHECK COMBINATION METER. 

    Check the combination meter. Refer to INSTRUMENTATION/DRIVER INFO>COMBINATION METER SYSTEM>OPERATION>SELF-DIAGNOSIS DISPLAY MODE .

    Is the check result OK?

    Yes:  Replace the VDC Control Module & H/U. Refer to VEHICLE DYNAMICS CONTROL (VDC)>VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDC Control Module & H/U) .

    No:  Replace the combination meter. Refer to INSTRUMENTATION/DRIVER INFO>COMBINATION METER .

Wiring diagram: 

• Models with EyeSight

  Parking brake/brake fluid level warning light system. Refer to WIRING SYSTEM>PARKING BRAKE/BRAKE FLUID LEVEL WARNING LIGHT SYSTEM>WIRING DIAGRAM>WITH EYESIGHT .

  Courtesy of SUBARU OF AMERICA, INC.

1. CHECK INSTALLATION OF VDC Control Module & H/U CONNECTOR. 
   1. Turn the ignition switch to OFF.
   2. Check that the VDC Control Module & H/U connector is inserted until it is locked by clamp.

   Is the connector firmly inserted?

   Yes:  Go to  2.

   No:  Insert the VDC Control Module & H/U connector until it is locked by clamp.

2. READ DTC. 

   Read the DTC. Refer to VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)>READ DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC displayed?

   Yes:  Perform the diagnosis according to DTC. Refer to VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)>LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .

   No:  Go to  3.

3. CHECK LAN SYSTEM. 

   Perform the diagnosis for LAN system. Refer to LAN SYSTEM (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .

   Is there any fault in LAN system?

   Yes:  Perform the diagnosis according to DTC for LAN system. Refer to LAN SYSTEM (DIAGNOSTICS)>LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .

   No:  Go to  4.

4. CHECK BRAKE FLUID AMOUNT. 

   Check the amount of brake fluid in the reservoir tank of master cylinder.

   Does the level of the brake fluid amount fall between the lines of "MAX" and "MIN"?

   Yes:  Go to  5.

   No:  Replenish brake fluid to the specified value.

5. CHECK BRAKE FLUID LEVEL SWITCH. 
   1. Turn the ignition switch to OFF.
   2. Disconnect the level switch connector (B16) from master cylinder.
   3. Measure the resistance of master cylinder terminals.

      Terminals 

      No. 1 - No. 2:

   Is the resistance 1 Ω or more?

   Yes:  Go to  6.

   No:  Replace the master cylinder. Refer to BRAKE>MASTER CYLINDER .

6. CHECK GROUND SHORT OF HARNESS. 
   1. Disconnect the connector from the combination meter.
   2. Measure the resistance between combination meter connector and chassis ground.

      Connector & terminal 

      (i10) No. 23 - Chassis ground:

   Is the resistance 1 Ω or more?

   Yes:  Go to  7.

   No:  Repair the harness connector between combination meter and brake fluid level switch.

7. CHECK COMBINATION METER. 

   Check the combination meter. Refer to INSTRUMENTATION/DRIVER INFO>COMBINATION METER SYSTEM>OPERATION>SELF-DIAGNOSIS DISPLAY MODE .

   Is the check result OK?

   Yes:  Replace the VDC Control Module & H/U. Refer to VEHICLE DYNAMICS CONTROL (VDC)>VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDC Control Module & H/U) .

   No:  Replace the combination meter. Refer to INSTRUMENTATION/DRIVER INFO>COMBINATION METER .