DESCRIPTION
The skid control ECU is connected to the combination meter via the CAN and multiplex communication systems.
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
Note
When replacing the skid control ECU, perform zero point calibration and store system information Click here.
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 MULTIPLEX COMMUNICATION SYSTEM
Check if a multiplex communication system DTC is output Click here.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
INSPECT MULTIPLEX 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 Click here |
| OK |
|
CHECK BATTERY
Check the battery voltage.
| Standard Voltage |
|---|
| 11 to 14 V |
| NG |
|
CHECK OR REPLACE CHARGING SYSTEM OR BATTERY (for 2UR-GSE) Click here |
| OK |
|
INSPECT SKID CONTROL ECU (IG1 TERMINAL)
Disconnect the skid control ECU connector.
Turn the engine switch on (IG).
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | ||||||
|---|---|---|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1 CIRCUIT) |
| OK |
|
INSPECT SKID CONTROL ECU (GND1 TERMINAL)
Turn the engine switch off.
Disconnect the skid control ECU connectors.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
*1: for LHD
*2: for RHD
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR (GND1 CIRCUIT) |
| OK |
|
READ VALUE USING INTELLIGENT TESTER (PARKING BRAKE SWITCH)
Reconnect the skid control ECU connectors.
Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG).
Select the Data List mode on 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 that the switch condition on the intelligent tester display changes according to parking brake pedal operation.
| OK |
|---|
| The intelligent tester displays ON or OFF according to parking brake pedal operation. |
| NG |
|
INSPECT PARKING BRAKE SWITCH Click here |
| OK |
|
INSPECT BRAKE FLUID LEVEL WARNING SWITCH
Turn the engine 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 are no problems 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) Click here |
| OK |
|
CHECK HARNESS AND CONNECTOR (COMBINATION METER - BRAKE FLUID LEVEL WARNING SWITCH)
Disconnect the combination meter 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
Perform the Active Test of the combination meter (meter CPU) using the intelligent tester Click here.
Check the combination meter.
Tech Tips
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 intelligent tester 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 the part Click here.
| NG |
|
REPLACE COMBINATION METER ASSEMBLY Click here |
| OK |
|
REPLACE SKID CONTROL ECU Click here
INSPECT PARKING BRAKE SWITCH
Turn the engine switch off.
Disconnect the parking brake switch connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
| NG |
|
REPLACE PARKING BRAKE SWITCH Click here |
| OK |
|
CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - PARKING BRAKE SWITCH)
Disconnect the skid control 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 the part Click here.
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
REPLACE SKID CONTROL ECU Click here