Brake Warning Light Remains on
BRAKE CONTROL: 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.
PROCEDURE
1. CHECK CAN COMMUNICATION SYSTEM
(a) Check if the CAN communication system DTC is output Diagnosis System.
Result:
B -- INSPECT 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. CHECK BATTERY
(a) Check the battery voltage.
Standard voltage:
11 to 14 V
NG -- CHECK OR REPLACE CHARGING SYSTEM OR BATTERY Testing and Inspection
OK -- Continue to next step.
4. INSPECT SKID CONTROL ECU (IG1 TERMINAL)
(a) Disconnect the 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:
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 to OFF.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:
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 a Techstream to the DLC3.
(c) Turn the ignition switch to ON.
(d) Select the Data List mode on the Techstream Data List / Active Test.
ABS/VSC/TRAC:
(e) Using the Techstream, check the input of 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 to 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:
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 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. INSPECT COMBINATION METER ASSEMBLY
(a) Connect the Techstream to the DLC3.
(b) Perform Active Test of the combination meter using the Techstream Meter / Gauge System.
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 -- REPLACE COMBINATION METER ASSEMBLY
OK -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal
10. REPLACE COMBINATION METER ASSEMBLY
(a) Turn the ignition switch to OFF.
(b) Replace the combination meter Removal.
NEXT -- Continue to next step.
11. INSPECT COMBINATION METER ASSEMBLY
(a) Connect the Techstream to the DLC3.
(b) Perform Active Test of the combination meter using the Techstream Meter / Gauge System.
OK:
The brake warning light turns ON or OFF in accordance with the Techstream.
NG -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal
OK -- END
12. INSPECT PARKING BRAKE SWITCH
(a) Turn the ignition switch to OFF.
(b) Disconnect the parking brake switch connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:
NG -- REPLACE PARKING BRAKE SWITCH Removal
OK -- Continue to next step.
13. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - PARKING BRAKE SWITCH)
(a) Disconnect the main body ECU connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal