DESCRIPTION
The skid control ECU is connected to the combination meter assembly 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.
The brake booster assembly is judged to be defective.
WIRING DIAGRAM
INSPECTION PROCEDURE
Note
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
PROCEDURE
CHECK CAN COMMUNICATION SYSTEM
Check if a CAN communication system DTC is output Click here.
Result | ||||||
---|---|---|---|---|---|---|
|
B |
INSPECT CAN COMMUNICATION SYSTEM Click here |
A |
CHECK IF SKID CONTROL ECU CONNECTOR IS SECURELY CONNECTED
Check if the skid control ECU connector is securely connected.
OK |
---|
The connector is securely connected. |
NG |
CONNECT CONNECTOR TO ECU CORRECTLY |
OK |
CHECK BATTERY
Check the battery voltage.
Standard Voltage |
---|
11 to 14 V |
Result | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|
|
B |
CHECK OR REPLACE CHARGING SYSTEM COMPONENT OR BATTERY Click here |
C |
CHECK OR REPLACE CHARGING SYSTEM COMPONENT OR BATTERY Click here |
D |
CHECK OR REPLACE CHARGING SYSTEM COMPONENT OR BATTERY Click here |
A |
CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)
*a | Front view of wire harness connector (to Skid Control ECU (Brake Actuator Assembly)) |
Disconnect the skid control ECU connector.
Measure the voltage according to the value(s) in the table below.
Standard Voltage | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT) |
OK |
CHECK HARNESS AND CONNECTOR (GND1 TERMINAL)
*a | Front view of wire harness connector (to Skid Control ECU (Brake Actuator Assembly)) |
Turn the ignition switch off.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||
---|---|---|---|---|---|---|
|
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR (GND1 CIRCUIT) |
OK |
READ VALUE USING INTELLIGENT TESTER (PARKING BRAKE SWITCH ASSEMBLY)
Reconnect the skid control ECU connector.
Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON.
Select the Data List using the intelligent tester Click here.
Tester Display | Measurement Item/Range | Normal Condition | Diagnostic Note |
---|---|---|---|
Parking Brake SW | Parking brake switch / ON or OFF | ON: Parking brake applied OFF: Parking brake released |
- |
Using the intelligent tester, check the switch operation signal received when the parking brake is operated.
OK |
---|
When the parking brake is operated, the display changes as shown above. |
NG |
INSPECT PARKING BRAKE SWITCH ASSEMBLY Click here |
OK |
INSPECT BRAKE FLUID LEVEL WARNING SWITCH
*a | Component without harness connected (Brake Fluid Level Warning Switch (Brake Master Cylinder Reservoir Sub-assembly)) |
Turn the ignition switch off.
Remove the reservoir filler cap and the strainer.
Disconnect the brake fluid level warning switch connector.
Measure the resistance according to the value(s) in the table below.
Tech Tips
A float is located inside the reservoir. Its position changes according to the brake fluid level.
Standard Resistance | |||||||||
---|---|---|---|---|---|---|---|---|---|
|
Tech Tips
If there is no problem after finishing the above check, adjust the brake fluid level to the MAX level.
Result | ||||||||
---|---|---|---|---|---|---|---|---|
|
B |
REPLACE BRAKE MASTER CYLINDER RESERVOIR SUB-ASSEMBLY Click here |
C |
REPLACE BRAKE MASTER CYLINDER RESERVOIR SUB-ASSEMBLY Click here |
A |
CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - BRAKE FLUID LEVEL WARNING SWITCH)
Disconnect the combination meter assembly connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
|
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
OK |
INSPECT COMBINATION METER ASSEMBLY
Reconnect the combination meter assembly connector and the brake fluid level warning switch connector.
Perform an Active Test of the combination meter assembly (meter CPU) using the intelligent tester Click here.
Check the combination meter assembly.
OK |
---|
The brake warning light turns on or off in accordance with the Active Test operation. |
Tech Tips
If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing parts Click here.
NG |
REPLACE COMBINATION METER ASSEMBLY Click here |
OK |
REPLACE BRAKE ACTUATOR ASSEMBLY Click here
INSPECT PARKING BRAKE SWITCH ASSEMBLY
*a | Component without harness connected (Parking Brake Switch Assembly) |
Turn the ignition switch off.
Disconnect the parking brake switch assembly connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | |||||||||
---|---|---|---|---|---|---|---|---|---|
|
Result | ||||||||
---|---|---|---|---|---|---|---|---|
|
B |
REPLACE PARKING BRAKE SWITCH ASSEMBLY Click here |
C |
REPLACE PARKING BRAKE SWITCH ASSEMBLY Click here |
A |
CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - PARKING BRAKE SWITCH ASSEMBLY)
Disconnect the main body ECU connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | |||||||||
---|---|---|---|---|---|---|---|---|---|
|
Tech Tips
If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing parts Click here.
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
OK |
REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here