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 skid control ECU is connected to the combination meter via CAN communication.

If any of the following is detected, the brake warning light remains on:

* The skid control ECU connector is disconnected from the skid control ECU.

* The brake fluid level is insufficient.

* The parking brake is applied.

* EBD operation is not possible.

WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
* When replacing the brake actuator assembly, perform zero point calibration Programming and Relearning.
* Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1. CHECK CAN COMMUNICATION SYSTEM

(a) Check if CAN communication system DTCs are output Diagnosis System.

Result





B -- CHECK CAN COMMUNICATION SYSTEM How to Proceed With Troubleshooting
A -- Continue to next step.

2. CHECK IF SKID CONTROL ECU CONNECTOR IS SECURELY CONNECTED

(a) Check if the skid control ECU connector is securely connected.

OK:

The connector is securely connected.

NG -- CONNECT CONNECTOR TO ECU CORRECTLY
OK -- Continue to next step.

3. INSPECT BATTERY

(a) Start the engine.

(b) Check the battery voltage.

Standard Voltage:





NG -- CHECK OR REPLACE CHARGING SYSTEM OR BATTERY Component Tests and General Diagnostics
OK -- Continue to next step.

4. INSPECT SKID CONTROL ECU (IG1 TERMINAL)

(a) Disconnect the A16 skid control ECU connector.

(b) Turn the ignition switch to ON.

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





Standard Voltage:





Text in Illustration





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1 CIRCUIT)
OK -- Continue to next step.

5. INSPECT SKID CONTROL ECU (GND TERMINAL)

(a) Turn the ignition switch off.

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





Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)
OK -- Continue to next step.

6. READ VALUE USING TECHSTREAM (PARKING BRAKE SWITCH)

(a) Reconnect the skid control ECU connector.

(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.

(f) According to the display on the Techstream, read the Data List.

ABS/VSC/TRAC





(g) 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.

7. INSPECT BRAKE FLUID LEVEL WARNING SWITCH

(a) Turn the ignition switch off.





(b) Remove the reservoir filler cap and strainer.

(c) Disconnect the brake fluid level warning switch connector.

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

HINT
A float is located inside the reservoir. Its position can be changed by increasing or decreasing the level of brake fluid.

Standard Resistance:





Text in Illustration





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

NG -- REPLACE BRAKE MASTER CYLINDER RESERVOIR ASSEMBLY (BRAKE FLUID LEVEL WARNING SWITCH) Disassembly
OK -- Continue to next step.

8. CHECK HARNESS AND CONNECTOR (COMBINATION METER - BRAKE FLUID LEVEL WARNING SWITCH)

(a) Disconnect the D2 combination meter connector.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

9. PERFORM ACTIVE TEST USING TECHSTREAM (BRAKE WARNING LIGHT)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Chassis / ABS/VSC/TRAC / Active Test.

(e) According to the display on the Techstream, perform the Active Test.

ABS/VSC/TRAC





OK:

The brake warning light turns ON or OFF in accordance with the Techstream.

HINT
Reinstall the connectors and restore the vehicle to its prior condition before checking the combination meter.

NG -- GO TO METER / GAUGE SYSTEM

OK -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal

10. INSPECT PARKING BRAKE SWITCH

(a) Turn the ignition switch off.





(b) Disconnect the parking brake switch connector.

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

Standard Resistance:





Text in Illustration





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

11. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK - PARKING BRAKE SWITCH))

(a) Disconnect the 3C instrument panel junction block assembly connector.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

12. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK - MAIN BODY ECU)

(a) Remove the main body ECU from the instrument panel junction block assembly.

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

Standard Resistance:





NG -- REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

OK -- REPLACE MAIN BODY ECU