Brake Warning Light Remains ON

BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: 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 EBD control is defective.

If the amount of brake fluid in the master cylinder reservoir is insufficient, DTCs related to the brake fluid are stored.

WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
When replacing the master cylinder solenoid, perform calibration Programming and Relearning.

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 ABS Warning Light Remains ON

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 engine switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the engine switch on (IG).

(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 engine switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the engine switch on (IG).

(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 -- REPLACE MASTER CYLINDER SOLENOID Disassembly

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

5. INSPECT PARKING BRAKE SWITCH

(a) Disconnect the A39 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 - MAIN BODY ECU)

(a) Disconnect the A39 parking brake switch connector.

(b) Remove the main body ECU (multiplex network body ECU) Removal.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)