Brake Warning Light Does Not Go Off

WARNING: This page is about a different variant/trim than selected.

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 (IMPREZA MODEL)>PARKING BRAKE/BRAKE FLUID LEVEL WARNING LIGHT SYSTEM . Ref. to WIRING SYSTEM (CROSSTREK MODEL (EXCEPT FOR HEV))>PARKING BRAKE/BRAKE FLUID LEVEL WARNING LIGHT SYSTEM .

Courtesy of SUBARU OF AMERICA, INC.

CAUTION: Before performing diagnosis, refer to "CAUTION" in "General Description". Ref. to BRAKE CONTROL (DIAGNOSTICS)>GENERAL DESCRIPTION>CAUTION .

CHECK INSTALLATION OF VDCCM AND H/U CONNECTOR .
1. Turn the ignition switch to OFF.
2. Check that the VDCCM and H/U connector is inserted until it is locked by clamp.
Is the connector firmly inserted?

Yes: Go to 2.

No: Insert the VDCCM and H/U connector until it is locked by clamp.
READ DTC .
Read the DTC of [Brake Control] using the Subaru Select Monitor. Ref. to BRAKE CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

Is DTC displayed?

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

No: Go to 3.
CHECK LAN SYSTEM .
Perform the diagnosis for LAN system using the Subaru Select Monitor. Ref. to LAN SYSTEM (DIAGNOSTICS) (EXCEPT FOR HEV)>BASIC DIAGNOSTIC PROCEDURE .

Is DTC of CAN communication displayed?

Yes: Perform the diagnosis according to the DTC. Ref. to LAN SYSTEM (DIAGNOSTICS) (EXCEPT FOR HEV)>DIAGNOSTIC TROUBLE CODE (DTC)>LIST .

No: Go to 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.
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 between 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 .
CHECK GROUND SHORT OF HARNESS .
1. Disconnect the connector from VDCCM.
2. Measure the resistance between VDCCM connector and chassis ground.
  Connector and terminal
  
  (B310) No. 35 - Chassis ground:
Is the resistance 1 MΩ or more?

Yes: Go to 7.

No: Repair the harness between VDCCM and brake fluid level switch.
CHECK PARKING BRAKE SWITCH .
1. Disconnect the connector (i286) 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.
CHECK GROUND SHORT OF HARNESS .
1. Disconnect the connector (i81) from body integrated unit.
2. Measure the resistance between body integrated unit connector and chassis ground.
  Connector and terminal
  
  (i81) No. 5 - 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.
CHECK POOR CONTACT OF CONNECTOR .
Check for poor contact of all connectors.

Is there poor contact?

Yes: Repair the connector.

No: Go to 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 and H/U. Ref. to VEHICLE DYNAMICS CONTROL (VDC)>VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDCCM AND H/U) .

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