Brake Warning Light Remains ON

BRAKE CONTROL: ANTI-LOCK BRAKE SYSTEM (for Sedan): Brake Warning Light Remains ON

Brake Warning Light Remains ON

DESCRIPTION

If any of the following conditions are detected, the BRAKE warning light remains on:
1. The ECU connectors are disconnected from the skid control ECU.
2. The brake fluid level is insufficient.
3. The parking brake is applied.
4. The EBD is defective.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. PREPARE FOR INSPECTION
(a) Check that both of the following conditions are satisfied.

- The brake fluid level in the brake master cylinder reservoir is correct.
- The parking brake is released.
HINT: When the ABS warning light remains illuminated, repair the malfunctions in the ABS system first.

NEXT -- Continue to next step.
2. CHECK DTC
(a) Check if any ABS DTCs are output ABS (Antilock Brake System) (for Sedan).
Result:






B -- REPAIR CIRCUITS INDICATED BY OUTPUT DTCS
A -- Continue to next step.
3. CHECK CAN COMMUNICATION SYSTEM
(a) Check if the CAN communication system DTC is output Diagnosis System.
Result:






B -- REPAIR CAN COMMUNICATION SYSTEM
A -- Continue to next step.
4. CHECK CONNECTOR CONNECTION CONDITION
(a) Check if the skid control ECU connector is connected securely.
OK:
The connector is connected securely.
NG -- CONNECTOR CORRECTLY
OK -- Continue to next step.
5. CHECK PARKING BRAKE SWITCH ASSEMBLY
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the tester on.
(d) Select the following menu items: Chassis / ABS/VSC/TRAC / Data List.

DATA LIST: ABS





(e) Check that "ON" and "OFF" are properly indicated on the tester display in accordance with the parking brake lever operation.
OK:
Tester display changes in accordance with the parking brake lever operation.
NG -- INSPECT PARKING BRAKE SWITCH ASSEMBLY
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.
HINT: There is a float inside the reservoir. Its position can be changed by increasing or decreasing the brake fluid level.

Standard resistance:





HINT: If there is no problem after the above check is finished, adjust the brake fluid level to the MAX level.

NG -- REPLACE BRAKE MASTER CYLINDER RESERVOIR SUB-ASSEMBLY
OK -- Continue to next step.
7. CHECK HARNESS AND CONNECTOR (COMBINATION METER - BRAKE FLUID LEVEL WARNING SWITCH)
(a) Disconnect the D2 combination meter connector.
(b) Disconnect the brake fluid level warning switch connector.




(c) Measure the resistance.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
8. INSPECT COMBINATION METER
(a) Inspect the combination meter assembly Meter / Gauge System (for Sedan).
NG -- REPLACE COMBINATION METER
OK -- REPLACE BRAKE ACTUATOR
9. INSPECT PARKING BRAKE SWITCH ASSEMBLY
(a) Disconnect the parking brake switch connector.




(b) Measure the resistance.
Standard resistance:






NG -- REPLACE PARKING BRAKE SWITCH ASSEMBLY
OK -- Continue to next step.
10. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - PARKING BRAKE SWITCH ASSEMBLY)




(a) Disconnect connector 4C of the main body ECU ABS (Antilock Brake System) (for Sedan).
(b) Disconnect the parking brake switch connector.
(c) Measure the resistance.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE MAIN BODY ECU