Brake Warning Light Circuit

BRAKE CONTROL: ANTI-LOCK BRAKE SYSTEM: Brake Warning Light Circuit

Brake Warning Light Circuit

DESCRIPTION

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

WIRING DIAGRAM





INSPECTION PROCEDURE
CAUTION: When releasing the parking brake, set the chocks to hold the vehicle for safety.

PROCEDURE

1. CHECK BRAKE FLUID
(a) Check that the brake fluid level is proper.
NG -- ADD BRAKE FLUID
OK -- Continue to next step.
2. CHECK DTC FOR ABS
(a) Are the DTC recorded Reading and Clearing Diagnostic Trouble Codes?
YES -- REPAIR CIRCUIT INDICATED BY OUTPUT CODE
NO -- Continue to next step.
3. CHECK BRAKE WARNING LIGHT
(a) WHEN USING INTELLIGENT TESTER:
(1) Connect the intelligent tester to the DLC3.
(2) Start the engine.
(3) Select the tester menus: DIAGNOSTIC, OBD/MOBD, ABS/VSC and ACTIVE TEST.
(4) Read the BRAKE WARN LIGHT status.






OK:
The BRAKE warning light turns on or off in accordance with the intelligent tester.





(b) WHEN NOT USING INTELLIGENT TESTER:
(1) Turn the ignition switch OFF and disconnect the S1 skid control ECU connector.
(2) Ground terminal BRL of the skid control ECU.
(3) Turn the ignition switch to the ON position.
(4) Check the BRAKE warning light.
OK:






OK -- REPLACE BRAKE ACTUATOR ASSEMBLY
NG -- Continue to next step.
4. INSPECT PARKING BRAKE SWITCH ASSEMBLY





(a) Remove the parking brake switch assembly.
(b) Measure the resistance of the parking brake switch.
Standard resistance:






NG -- REPLACE PARKING BRAKE SWITCH ASSEMBLY
OK -- Continue to next step.
5. CHECK WIRE HARNESS (PARKING BRAKE SWITCH ASSEMBLY - SKID CONTROL ECU)





(a) Disconnect the S1 skid control ECU connector.
(b) Disconnect the P6 parking brake switch assembly connector.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- Continue to next step.
6. INSPECT BRAKE FLUID LEVEL WARNING SWITCH





(a) Remove the reservoir tank cap and strainer.
(b) Disconnect the brake fluid level warning switch connector.
(c) Measure the resistance of the brake fluid level warning switch.
Standard resistance:






NG -- REPLACE BRAKE MASTER CYLINDER RESERVOIR SUB-ASSEMBLY
OK -- Continue to next step.
7. CHECK WIRE HARNESS (BRAKE FLUID LEVEL WARNING SWITCH - COMBINATION METER)





(a) Disconnect the C6 combination meter connector.
(b) Disconnect the B2 brake fluid level warning switch connector.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- Continue to next step.
8. CHECK WIRE HARNESS (SKID CONTROL ECU - COMBINATION METER)





(a) Disconnect the S1 skid control ECU connector.
(b) Disconnect the C6 combination meter connector.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- Continue to next step.
9. INSPECT COMBINATION METER ASSEMBLY
(a) Check combination meter assembly Problem Symptoms Table.
NG -- CHECK COMBINATION METER ASSEMBLY
OK -- REPLACE BRAKE ACTUATOR ASSEMBLY