DESCRIPTION
The skid control ECU 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.
except Multi-information Display Type:
If TRC and VSC operations are turned off, the TRC OFF indicator and the VSC OFF indicator lights come on.
for 4WD:
When the 4WD control switch (transfer position switch) set to L4, VSC is prohibited and the VSC OFF indicator light turns on.
w/ Rear Differential Lock:
When the rear differential is locked, VSC is prohibited, and the VSC OFF and TRC OFF indicator lights turn on.
for Multi-information Display Type:
If TRC and VSC operations are turned off, the TRC OFF message will be displayed on the multi-information display and the VSC OFF indicator light will come on.
for 4WD:
When the 4WD control switch (transfer position switch) set to L4, VSC is prohibited and the VSC OFF indicator light turns on.
w/ Rear Differential Lock:
When the rear differential is locked, VSC is prohibited, the VSC OFF indicator turns on and the TRC OFF message is displayed.
WIRING DIAGRAM
*a | VSC OFF Switch |
*b | Combination Meter Assembly |
*c | Skid Control ECU (Brake Actuator Assembly) |
*d | CAN Communication Line |
CAUTION / NOTICE / HINT
Note
When replacing the skid control ECU (brake actuator assembly), perform zero point calibration and store system information.
for 4WD:
As there may be malfunctions in the touch select 2-4 and high-low system related to when the transfer operates in L4, check the touch select 2-4 and high-low system first.
PROCEDURE
CHECK CAN COMMUNICATION SYSTEM
Check if CAN communication system DTCs are output.
for LHD with Central Gateway ECU: Click here
for RHD with Central Gateway ECU: Click here
for LHD without Central Gateway ECU: Click here
for RHD without Central Gateway ECU: Click here
Result | |||
---|---|---|---|
|
DTC is output |
CHECK CAN COMMUNICATION SYSTEM for LHD with Central Gateway ECU: Click here |
DTC is not output |
CHECK IF SKID CONTROL ECU ASSEMBLY CONNECTOR IS SECURELY CONNECTED
Check if the skid control ECU assembly (brake actuator assembly) connector is securely connected.
OK |
---|
The connector is securely connected. |
Result | ||||
---|---|---|---|---|
|
OK (w/o Rear Differential Lock) |
GO TO STEP 4 Click here |
NG |
CONNECT CONNECTOR TO SKID CONTROL ECU ASSEMBLY CORRECTLY |
OK (w/ Rear Differential Lock) |
CHECK FOR DIFFERENTIAL SYSTEM
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Enter the following menus: Powertrain / Four Wheel Drive / Trouble Codes.
Check for DTCs.
Result | |||
---|---|---|---|
|
DTCs are output |
GO TO DIFFERENTIAL SYSTEM (DIAGNOSTIC TROUBLE CODE CHART) Click here |
DTCs are not output |
READ VALUE USING GTS (TRC/VSC OFF MODE)
Reconnect the A4 skid control ECU (brake actuator assembly) connector.
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Select the Data List on the GTS.
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 VSC OFF: VSC off mode |
Unknown: Unspecified |
Tester Display |
---|
TRC/VSC Off Mode |
Check that the indicator light and mode condition on the GTS change according to VSC OFF switch operation.
Standard | ||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
except Multi-information Display Type | ||||||||||||||||
|
||||||||||||||||
for Multi-information Display Type | ||||||||||||||||
|
Result | ||||||||
---|---|---|---|---|---|---|---|---|
|
B |
INSPECT METER / GAUGE SYSTEM Click here |
C |
USE SIMULATION METHOD TO CHECK Click here |
A |
PERFORM ACTIVE TEST USING GTS (MULTI-INFORMATION DISPLAY AND VSC OFF INDICATOR LIGHT)
Select the Active Test on the GTS.
Tester Display | Measurement Item | Control Range | Diagnostic Note |
---|---|---|---|
TRC(TRAC) OFF Indicator Light |
|
|
Observe combination meter assembly Vehicle condition: Vehicle stopped |
VSC OFF Indicator Light | VSC OFF indicator light | Indicator light ON/OFF | Observe combination meter assembly Vehicle condition: Vehicle stopped |
*1: except Multi-information Display Type
*2: for Multi-information Display Type
Tester Display |
---|
TRC(TRAC) OFF Indicator Light |
Tester Display |
---|
VSC OFF Indicator Light |
except Multi-information Display Type:
Check the TRC OFF indicator light and VSC OFF indicator light on the combination meter assembly turn ON or OFF in accordance with the GTS operation.
OK |
---|
The TRC OFF indicator light and VSC OFF indicator light turn ON or OFF in accordance with the GTS operation. |
for Multi-information Display Type:
Check the multi-information display (TRC OFF message) and VSC OFF indicator light on the combination meter assembly turn ON or OFF in accordance with the GTS operation.
OK |
---|
The multi-information display (TRC OFF message) and VSC OFF indicator light turn ON or OFF in accordance with the GTS operation. |
Result | |||
---|---|---|---|
|
NG |
INSPECT COMBINATION METER ASSEMBLY Click here |
OK |
INSPECT VSC OFF SWITCH
Turn the ignition switch off.
Remove the VSC OFF switch.
Inspect the VSC OFF switch.
OK |
---|
The VSC OFF switch operates normally. |
Result | |||
---|---|---|---|
|
NG |
REPLACE VSC OFF SWITCH Click here |
OK |
CHECK HARNESS AND CONNECTOR (BRAKE ACTUATOR ASSEMBLY - VSC OFF SWITCH)
Disconnect the A4 skid control ECU (brake actuator assembly) connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Result | |||
---|---|---|---|
|
OK |
REPLACE BRAKE ACTUATOR ASSEMBLY Click here |
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
INSPECT COMBINATION METER ASSEMBLY
Turn the ignition switch off.
except Multi-information Display Type:
Perform the Active Test of the combination meter assembly using the GTS.
Tester Display |
---|
VSC TRC Indicator |
Tester Display |
---|
Indicat. VSC OFF |
for Multi-information Display Type:
Perform the Active Test of the combination meter assembly using the GTS.
Tester Display |
---|
Meter Display 1 |
Tester Display |
---|
Indicat. VSC OFF |
Check the combination meter assembly.
OK |
---|
except Multi-information Display Type: |
The TRC OFF indicator light turns on or off in accordance with the GTS. |
for Multi-information Display Type: |
The multi-information display and VSC OFF indicator light turns on or off in accordance with the GTS operation. |
Result | |||
---|---|---|---|
|
OK |
REPLACE BRAKE ACTUATOR ASSEMBLY Click here |
NG |
INSPECT METER / GAUGE SYSTEM Click here |