DESCRIPTION
The brake actuator assembly (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 brake actuator assembly (skid control ECU) connector is disconnected from the brake actuator assembly (skid control ECU).
The brake fluid level is insufficient.
The parking brake is applied.
EBD operation is not possible.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
Note
When replacing the brake actuator assembly (skid control ECU)y, perform zero point calibration Click here.
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
PROCEDURE
CHECK CAN COMMUNICATION SYSTEM
Check if CAN communication system DTCs are output Click here.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
CHECK CAN COMMUNICATION SYSTEM Click here |
| A |
|
CHECK IF SKID CONTROL ECU CONNECTOR IS SECURELY CONNECTED
Check if the brake actuator assembly (skid control ECU) connector is securely connected.
| OK |
|---|
| The connector is securely connected. |
| NG |
|
CONNECT CONNECTOR TO ECU CORRECTLY |
| OK |
|
INSPECT BATTERY
Check the battery voltage.
| Standard voltage |
|---|
| 11 to 14 V |
| Result | ||||||||
|---|---|---|---|---|---|---|---|---|
|
| B |
|
CHECK OR REPLACE CHARGING SYSTEM OR BATTERY Click here |
| C |
|
CHECK OR REPLACE CHARGING SYSTEM OR BATTERY Click here |
| A |
|
CHECK TERMINAL VOLTAGE (IG1 TERMINAL)
Disconnect the A54 or A56 brake actuator assembly (skid control ECU) connector.
Turn the ignition switch to ON.
| *A | except LHD with CVT |
| *B | for LHD with CVT |
| *a | Front view of wire harness connector (to Brake actuator assembly (Skid control ECU)) |
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | ||||||
|---|---|---|---|---|---|---|
|
||||||
|
Reconnect the A54 or A56 brake actuator assembly (skid control ECU) connector.
| Result | ||||||||
|---|---|---|---|---|---|---|---|---|
|
| B |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1 CIRCUIT) |
| C |
|
GO TO STOP AND START SYSTEM Click here |
| A |
|
CHECK HARNESS AND CONNECTOR (GND1 TERMINAL)
Turn the ignition switch off.
Disconnect the A54 or A56 brake actuator assembly (skid control ECU) connector.
| *A | except LHD with CVT |
| *B | for LHD with CVT |
| *a | Front view of wire harness connector (to Brake actuator assembly (Skid control ECU)) |
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
||||||
|
Reconnect the A54 or A56 brake actuator assembly (skid control ECU) connector.
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT) |
| OK |
|
READ VALUE USING INTELLIGENT TESTER (PARKING BRAKE SWITCH)
Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON.
Enter the following menus: Chassis / ABS/VSC/TRC / Data List.
| 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 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 ASSEMBLY Click here |
| OK |
|
INSPECT BRAKE FLUID LEVEL WARNING SWITCH
| *a | Component without harness connected (Brake Fluid Level Warning Switch) |
Turn the ignition switch off.
Remove the reservoir filler cap and 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 can be changed by increasing or decreasing the level of brake fluid.
| Standard Resistance | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Tech Tips
If there is no problem after finishing the above check, adjust the brake fluid level to the MAX level.
Reconnect the brake fluid level warning switch connector.
Reinstall the reservoir filler cap and strainer.
| Result | ||||||||
|---|---|---|---|---|---|---|---|---|
|
| B |
|
REPLACE BRAKE MASTER CYLINDER RESERVOIR ASSEMBLY (BRAKE FLUID LEVEL WARNING SWITCH) Click here |
| C |
|
REPLACE BRAKE MASTER CYLINDER RESERVOIR ASSEMBLY (BRAKE FLUID LEVEL WARNING SWITCH) Click here |
| A |
|
CHECK HARNESS AND CONNECTOR (COMBINATION METER - BRAKE FLUID LEVEL WARNING SWITCH)
Disconnect the F1 combination meter assembly connector and the A25 brake fluid level warning switch.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance (Check for Open) | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
| Standard Resistance (Check for Short) | ||||||
|---|---|---|---|---|---|---|
|
Reconnect the combination meter assembly connector and the brake fluid level warning switch.
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
INSPECT COMBINATION METER ASSEMBLY
Connect the intelligent tester to the DLC3.
Perform Active Test of the combination meter assembly using the intelligent tester Click here.
| OK |
|---|
| The brake warning light turns ON or OFF in accordance with the intelligent tester. |
| Result | ||||||||
|---|---|---|---|---|---|---|---|---|
|
Tech Tips
Reinstall the connectors and restore the vehicle to its prior condition before checking the combination meter assembly.
| B |
|
REPLACE BRAKE ACTUATOR ASSEMBLY (SKID CONTROL ECU) Click here |
| C |
|
REPLACE BRAKE ACTUATOR ASSEMBLY (SKID CONTROL ECU) Click here |
| A |
|
REPLACE COMBINATION METER ASSEMBLY
Turn the ignition switch off.
Replace the combination meter assembly Click here.
| NEXT |
|
INSPECT COMBINATION METER ASSEMBLY
Connect the intelligent tester to the DLC3.
Perform Active Test of the combination meter assembly using the intelligent tester Click here.
| OK |
|---|
| The brake warning light turns ON or OFF in accordance with the intelligent tester. |
| Result | ||||||||
|---|---|---|---|---|---|---|---|---|
|
| A |
|
END |
| B |
|
REPLACE BRAKE ACTUATOR ASSEMBLY (SKID CONTROL ECU) Click here |
| C |
|
REPLACE BRAKE ACTUATOR ASSEMBLY (SKID CONTROL ECU) Click here |
INSPECT PARKING BRAKE SWITCH ASSEMBLY
Remove the parking brake switch assembly.
Inspect the parking brake switch assembly.
Reconnect the parking brake switch assembly connector.
| Result | ||||||||
|---|---|---|---|---|---|---|---|---|
|
| B |
|
REPLACE PARKING BRAKE SWITCH ASSEMBLY Click here |
| C |
|
REPLACE PARKING BRAKE SWITCH ASSEMBLY Click here |
| A |
|
CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK - PARKING BRAKE SWITCH)
Disconnect the 3A instrument panel junction block assembly connector and the F22 parking brake switch assembly connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance (Check for Open) | ||||||
|---|---|---|---|---|---|---|
|
| Standard Resistance (Check for Short) | ||||||
|---|---|---|---|---|---|---|
|
Reconnect the 3A instrument panel junction block assembly connector and the F22 parking brake switch assembly connector.
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY
Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.
Disconnect the 3A instrument panel junction block assembly connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Reconnect the 3A instrument panel junction block assembly connector.
Reinstall the main body ECU (multiplex network body ECU) to the instrument panel junction block assembly.
| OK |
|
REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here |
| NG |
|
REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY |