Brake Warning Light Does Not Go Off

Detecting condition: 

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

Trouble symptom: 

Brake warning light does not go off after starting the engine.

Wiring diagram: 

Parking brake/brake fluid level warning light system Ref. to WIRING SYSTEM>PARKING BRAKE/BRAKE FLUID LEVEL WARNING LIGHT SYSTEM .

Combination meter system Ref. to WIRING SYSTEM>COMBINATION METER SYSTEM .

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 using Subaru Select Monitor. Ref. to BRAKE CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC displayed?

   Yes:  Perform the diagnosis according to DTC. Ref. to BRAKE CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC)>LIST .

   No:  Go to  3.

3. CHECK LAN SYSTEM. 

   Check the LAN system. Ref. to LAN SYSTEM (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .

   Is the check result OK?

   Yes:  Go to  4.

   No:  Perform the diagnosis for LAN system.

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 VDC Control Module.
   2. Measure the resistance between VDC Control Module connector and chassis ground.

      Connector & terminal 

      (B310) No. 27 - Chassis ground:

      Is the resistance 1 MΩ or more?

      Yes:  Go to  7.

      No:  Repair the harness between VDC Control Module 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 VDC Control Module & H/U. Ref. to VEHICLE DYNAMICS CONTROL (VDC)>VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDC Control Module & H/U) .

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