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 Ref. 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 VDCCM&H/U CONNECTOR  .
   1. Turn the ignition switch to OFF.
   2. Check that the VDCCM&H/U connector is inserted until it is locked by clamp.

   Is the connector firmly inserted?

   Yes: Go to  2.

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

2. READ DTC  .

   Read the DTC. Ref. to VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)>Read Diagnostic Trouble Code (DTC) .

   Is DTC displayed?

   Yes: Perform the diagnosis according to DTC. Ref. 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. Ref. to LAN SYSTEM (DIAGNOSTICS)>Basic Diagnostic Procedure .

   Is there any fault in LAN system?

   Yes: Perform the diagnosis according to DTC for LAN system. Ref. 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 MΩ or more?

   Yes: Go to  6.

   No: Replace the master cylinder. Ref. 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 MΩ 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 MΩ 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 MΩ 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. Ref. to INSTRUMENTATION/DRIVER INFO>Combination Meter System>OPERATION>SELF-DIAGNOSIS DISPLAY MODE .

    Is the check result OK?

    Yes: Replace the VDCCM&H/U. Ref. to VEHICLE DYNAMICS CONTROL (VDC)>VDC Control Module and Hydraulic Control Unit (VDCCM&H/U) .

    No: Replace the combination meter. Ref. to INSTRUMENTATION/DRIVER INFO>Combination Meter .

    Wiring diagram: 

    • Models with EyeSight

      Parking brake/brake fluid level warning light system Ref. 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 VDCCM&H/U CONNECTOR  .
   1. Turn the ignition switch to OFF.
   2. Check that the VDCCM&H/U connector is inserted until it is locked by clamp.

   Is the connector firmly inserted?

   Yes: Go to  2.

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

2. READ DTC  .

   Read the DTC. Ref. to VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)>Read Diagnostic Trouble Code (DTC) .

   Is DTC displayed?

   Yes: Perform the diagnosis according to DTC. Ref. 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. Ref. to LAN SYSTEM (DIAGNOSTICS)>Basic Diagnostic Procedure .

   Is there any fault in LAN system?

   Yes: Perform the diagnosis according to DTC for LAN system. Ref. 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 MΩ or more?

   Yes: Go to  6.

   No: Replace the master cylinder. Ref. 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 MΩ 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. Ref. to INSTRUMENTATION/DRIVER INFO>Combination Meter System>OPERATION>SELF-DIAGNOSIS DISPLAY MODE .

   Is the check result OK?

   Yes: Replace the VDCCM&H/U. Ref. to VEHICLE DYNAMICS CONTROL (VDC)>VDC Control Module and Hydraulic Control Unit (VDCCM&H/U) .

   No: Replace the combination meter. Ref. to INSTRUMENTATION/DRIVER INFO>Combination Meter .