DESCRIPTION
The skid control ECU (brake booster with master cylinder assembly) is connected to the combination meter assembly via CAN communication.
Pressing the VSC OFF switch turns off TRC operation, and pressing and holding this switch turns off TRC and VSC operation. If TRC and VSC operations are turned off, the TRC OFF indicator light and the VSC OFF indicator light will come on.
WIRING DIAGRAM
*a | VSC OFF Switch |
*b | Combination Meter Assembly |
*c | Skid Control ECU (Brake Booster with Master Cylinder Assembly) |
*d | CAN Communication Line |
CAUTION / NOTICE / HINT
Note
When replacing the skid ECU (brake actuator assembly), perform zero point calibration and store system information.
PROCEDURE
CHECK CAN COMMUNICATION SYSTEM
Check if CAN communication system DTCs are output.
w/o Toyota Safety Sense Click here
w/ Toyota Safety Sense Click here
Result | Proceed to |
---|---|
DTC is not output. | A |
CAN communication system DTC is output. (w/o Toyota Safety Sense) | B |
CAN communication system DTC is output. (w/ Toyota Safety Sense) | C |
B |
INSPECT CAN COMMUNICATION SYSTEM Click here |
C |
INSPECT CAN COMMUNICATION SYSTEM Click here |
A |
CHECK IF BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY CONNECTOR IS SECURELY CONNECTED
Check if the skid control ECU (brake booster with master cylinder assembly) connector is securely connected.
OK |
---|
The connector is securely connected. |
NG |
CONNECT CONNECTOR TO BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY CORRECTLY |
OK |
READ VALUE USING GTS (TRC/VSC OFF MODE)
Turn the ignition switch off.
Connect the GTS to the DLC3.
Turn the ignition switch to ON (IG).
Turn the GTS on.
Enter the following menus: Chassis / ABS/VSC/TRC / Data List.
According to the display on the GTS, read the Data List.
Tester Display | Measurement Item/Range | Normal Condition | Diagnostic Note |
---|---|---|---|
TRC/VSC Off Mode | TRC/VSC off mode / Normal, TRC OFF, Unknown or VSC OFF |
NORMAL: Normal mode TRC OFF: TRC off mode Unknown: Unspecified VSC OFF: VSC off mode |
- |
Check the indicator light and mode condition on the GTS changes according to VSC OFF switch operation.
Standard: | ||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Result | Proceed to |
---|---|
Indicator light and mode condition display do not change. | A |
Mode condition display is normal, but indicator light does not change. | B |
Yaw rate and acceleration sensor DTC is output. Indicator light and mode condition display is normal. | C |
B |
INSPECT METER / GAUGE SYSTEM Click here |
C |
USE SIMULATION METHOD TO CHECK |
A |
PERFORM ACTIVE TEST USING GTS (VSC OFF INDICATOR LIGHT AND VSC OFF INDICATOR LIGHT)
Turn the ignition switch off.
Connect the GTS to the DLC3.
Turn the ignition switch to ON (IG).
Turn the GTS on.
Enter the following menus: Chassis / ABS/VSC/TRC / Active Test.
According to the display on the GTS, perform the Active Test.
Tester Display | Test Part | Control Range | Diagnostic Note |
---|---|---|---|
TRC(TRAC) OFF Indicator Light | TRC OFF indicator light | Indicator light ON/OFF | Observe combination meter assembly |
VSC OFF Indicator Light | VSC OFF indicator light | Indicator light ON/OFF | Observe combination meter assembly |
Check the TRC OFF indicator light and VSC OFF indicator light in the combination meter assembly turn on or off in accordance with GTS operation.
OK |
---|
The TRC OFF indicator light and VSC OFF indicator light turn on or off in accordance with GTS operation. |
NG |
INSPECT COMBINATION METER ASSEMBLY Click here |
OK |
INSPECT VSC OFF SWITCH
Remove the VSC OFF switch Click here.
Inspect the VSC OFF switch Click here.
NG |
REPLACE VSC OFF SWITCH Click here |
OK |
CHECK HARNESS AND CONNECTOR (VSC OFF SWITCH - BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY AND BODY GROUND)
Disconnect the A29 skid control ECU (brake booster with master cylinder assembly) connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Result | Proceed to |
---|---|
NG (for LHD) | A |
NG (for RHD) | B |
OK | C |
A |
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY Click here |
B |
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY Click here |
C |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
INSPECT COMBINATION METER ASSEMBLY
Turn the ignition switch off.
Connect the GTS to the DLC3.
Turn the ignition switch to ON (IG).
Turn the GTS on.
Enter the following menus: Body Electrical / Combination Meter / Active Test.
According to the display on the GTS, perform the Active Test.
Tester Display | Test Part | Control Range | Diagnostic Note |
---|---|---|---|
VSC TRC Indicator | TRC OFF indicator light | OFF or ON | - |
Indicat. VSC OFF | VSC OFF indicator light | OFF or ON | - |
Check the TRC OFF indicator light and VSC OFF indicator light in the combination meter assembly turn on or off in accordance with GTS operation.
OK |
---|
The TRC OFF indicator light and VSC OFF indicator light turn on or off in accordance with GTS 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.
Result | Proceed to |
---|---|
NG (for LHD) | A |
NG (for RHD) | B |
OK | C |
A |
BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY Click here |
B |
BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY Click here |
C |
INSPECT METER / GAUGE SYSTEM Click here |