Brake Warning Light Remains ON
BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM (for 2ZR-FE): 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 has been disabled.
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 a 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 (for 2ZR-FE) Component Tests and General Diagnostics
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 (GND1 TERMINAL)
(a) Turn the ignition switch off.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (GND1 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) Select Data List mode on the Techstream Data List / Active Test.
ABS / VSC / TRAC
(e) Using the Techstream, check the switch operation when the parking brake is applied.
OK:
The Techstream displays ON or OFF according to parking brake operation.
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:
HINT
If there are no problems after finishing the check above, adjust the brake fluid level to the MAX level.
NG -- REPLACE BRAKE MASTER CYLINDER RESERVOIR ASSEMBLY (BRAKE FLUID LEVEL WARNING SWITCH) Removal
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) Perform the Active Test of the combination meter (meter CPU) using the Techstream.
(b) Check the combination meter.
HINT
Reinstall the connectors and restore the vehicle to its prior condition before checking the combination meter.
OK:
The brake warning light turns on or off in accordance with the Techstream operation.
HINT
If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step before replacing the part Problem Symptoms Table.
NG -- REPLACE COMBINATION METER ASSEMBLY Removal
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:
NG -- REPLACE PARKING BRAKE SWITCH Removal
OK -- Continue to next step.
11. 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:
HINT
If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step before replacing the part Problem Symptoms Table.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE MAIN BODY ECU (DRIVER SIDE JUNCTION BLOCK)