Brake Warning Light Remains ON

BRAKE CONTROL: VEHICLE STABILITY CONTROL SYSTEM: Brake Warning Light Remains ON
- Brake Warning Light Remains ON

DESCRIPTION

The BRAKE warning light comes on when brake fluid is insufficient, the parking brake is applied or the EBD is defective.

WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
When replacing the master cylinder solenoid, perform calibration Calibration.

PROCEDURE

1. CHECK DTC

(a) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

Result





B -- REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Vehicle Stability Control System
A -- Continue to next step.

2. CHECK CAN COMMUNICATION LINE

(a) Turn the ignition switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the ignition switch to ON.

(d) Turn the Techstream on.

(e) Select CAN Bus Check from the System Selection Menu screen and follow the prompts on the screen to inspect the CAN bus Diagnosis System.

OK:

CAN bus Check indicates no malfunctions in CAN communication.

NG -- GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) How to Proceed With Troubleshooting
OK -- Continue to next step.

3. READ VALUE USING TECHSTREAM (PARKING BRAKE SW)

(a) Turn the ignition switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the ignition switch to ON.

(d) Turn the Techstream on.

(e) Enter the following menus: Chassis / ABS/VSC/TRAC / Data List.

ABS/VSC/TRAC





(f) Using the Techstream, check the input of the switch operation when the parking brake pedal is operated.

OK:

When the parking brake is operated, the display changes as shown above.

NG -- INSPECT PARKING BRAKE SWITCH
OK -- Continue to next step.

4. READ VALUE USING TECHSTREAM (BRAKE WARNING LIGHT)

(a) Turn the ignition switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the ignition switch to ON.

(d) Turn the Techstream on.

(e) Enter the following menus: Chassis / ABS/VSC/TRAC / Data List.

ABS/VSC/TRAC





(f) When performing the Brake Warning Light Active Test, check Brake Warning Light in the Data List Data List / Active Test.

ABS/VSC/TRAC





Result





B -- GO TO METER / GAUGE SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) How To Proceed With Troubleshooting

A -- REPLACE MASTER CYLINDER SOLENOID Disassembly

5. INSPECT PARKING BRAKE SWITCH

(a) Disconnect the E22 parking brake switch connector.

(b) Measure the resistance according to the value(s) in the table below.





Standard Resistance:





Text in Illustration





NG -- REPLACE PARKING BRAKE SWITCH ASSEMBLY Removal
OK -- Continue to next step.

6. CHECK HARNESS AND CONNECTOR (PARKING BRAKE SWITCH - SKID CONTROL ECU

(a) Disconnect the E22 parking brake switch connector.

(b) Disconnect the A4 skid control ECU connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE MASTER CYLINDER SOLENOID Disassembly