2003 LEXUS LS430 replacement

INSPECTION PROCEDURE
1.CHECK DTC
a. Is DTC output for ABS, CAN and/or MPX?
OK: Go to next step
DTC OUTPUT DESCRIPTION
B: REPAIR CIRCUIT INDICATED BY OUTPUT CODE
A: Go to next step
2.INSPECT SKID CONTROL ECU CONNECTOR (SEE REPLACEMENT
)
a. Check the ECU connectors connecting condition.
OK: Go to next step
The connector is securely connected.
NG: CONNECT CONNECTOR TO ECU CORRECTLY
OK: Go to next step
3.INSPECT BATTERY
a. Check the battery voltage.
Standard:
Voltage: 10 to 14 V
NG: INSPECT CHARGING SYSTEM (SEE ON
-VEHICLE INSPECTION )
OK: Go to next step
4.INSPECT SKID CONTROL ECU TERMINAL VOLTAGE (IG1 TERMINAL)
a. Connect the hand-held tester to the DLC3.
b. Start the engine.
c. Select the DATA LIST mode on the han
d-held tester.
DTC is not outputA
DTC is outputB

Fig. 114: Identifying Skid Control ECU Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
WIRING DIAGRAM

a. Is the DTC output for CAN communication system?
Result:
DTC OUTPUT DESCRIPTION
B: REPAIR CAN COMMUNICATION SYSTEM (SEE PRECAUTION
)
A: Go to next step
2.INSPECT MULTIPLEX COMMUNICATION SYSTEM
a. Is the DTC output for Multiplex communication system?
Result:
DTC OUTPUT DESCRIPTION
B: REPAIR MULTIPLEX COMMUNICATION SYSTEM (SEE DIAGNOSTIC TROUBLE
CODE CHART )
A: Go to next step
3.INSPECT ABS WARNING LIGHT
a. Connect the hand-held tester to the DLC3 and start the engine.
b. Select the item "ABS WARN LIGHT" in the ACTIVE TEST and operate the ABS warning light on
the hand-held tester.
VEHICLE CONDITION / TEST DETAILS
c. Check that "ON" and "OFF" of the ABS warning light can be shown on the combination meter by
the hand-held tester.
Standard:
Turn the ABS warning light ON or OFF in accordance with the hand-held tester.
NG: CHECK AND REPAIR ABS WARNING LIGHT CIRCUIT
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
DTC is not outputA
DTC is outputB
DTC is not outputA
DTC is outputB
ItemVehicle Condition / Test DetailsDiagnostic Note
ABS WARN LIGHTTurns ABS warning light ON / OFFObserve combination meter

Standard:
DTC OUTPUT DESCRIPTION
B: REPAIR CIRCUIT INDICATED BY OUTPUT DTC
A: Go to next step
2.INSPECT SKID CONTROL ECU CONNECTOR (SEE REPLACEMENT
)
a. Check the ECU connector's connecting condition.
OK: Go to next step
The connector is securely connected.
NG: CONNECT CONNECTOR TO ECU CORRECTLY
OK: Go to next step
3.INSPECT BATTERY
a. Check the battery voltage.
Standard:
Voltage: 10 to 14 V
NG: INSPECT CHARGING SYSTEM (SEE ON
-VEHICLE INSPECTION )
OK: Go to next step
4.INSPECT SKID CONTROL ECU TERMINAL VOLTAGE (IG1 TERMINAL)
a. Connect the hand-held tester to the DLC3.
b. Start the engine.
c. Select the DATA LIST mode on the hand-held tester.
Fig. 117: Item Measurement Item /Range Normal Condition

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
DTC is not outputA
DTC is outputB

Fig. 118: Identifying Skid Control ECU Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
If the ECU stores DTC, the VSC warning light comes on in the combination meter.
The skid control ECU is connected to the combination meter via CAN and MPX communications.
WIRING DIAGRAM

Result:
DTC OUTPUT DESCRIPTION
B: REPAIR CAN COMMUNICATION SYSTEM (SEE PRECAUTION
)
A: Go to next step
2.INSPECT MULTIPLEX COMMUNICATION SYSTEM
a. Is the DTC output for Multiplex communication system?
Result:
DTC OUTPUT DESCRIPTION
B: REPAIR MULTIPLEX COMMUNICATION SYSTEM (SEE DIAGNOSTIC TROUBLE
CODE CHART )
A: Go to next step
3.CHECK MULTI INFORMATION DISPLAY (VSC WARNING)
a. Connect the hand-held tester to the DLC3 and start the engine.
b. Select the item "VSC WARN LIGHT" in the ACTIVE TEST and operate the VSC warning light on
the hand-held tester.
VEHICLE CONDITION / TEST DETAILS
c. Check that "ON" and "OFF" of the VSC warning light are indicated on the combination meter
when using the hand-held tester.
OK: Go to next step
Turn the VSC warning light ON or OFF in accordance with the hand-held tester.
NG: CHECK AND REPAIR VSC WARNING LIGHT CIRCUIT
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
DTC is not outputA
DTC is outputB
DTC is not outputA
DTC is outputB
ItemVehicle Condition / Test DetailsDiagnostic Note
VSC WARN LIGHTTurns VSC warning light ON / OFFObserve combination meter

OK: Go to next step
Turn the BRAKE warning light on or off in accordance with the hand-held tester.
NG: Go to step 4
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
4.INSPECT PARKING BRAKE SWITCH ASSY
a. Remove the parking brake switch connector.
b. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
NG: REPLACE PARKING BRAKE SWITCH ASSY
Tester ConnectionSwitch ConditionSpecified Condition
P3-1 - Ground partReleasedBelow 1 ohms
P3-1 - Ground partPushed in1M ohms or higher

Fig. 126: Inspecting Pad Wear Indicator Wire Assy
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
REAR:
HINT:
Check that there are no scratches or cracks on the pad wear indicator.
a. Remove the rear wheel RH.
b. Disconnect the pad wear indicator connector.
c. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
NG: REPLACE PAD WEAR INDICATOR WIRE ASSY
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
The skid control ECU detects the TRAC control main switch ON/OFF signal and turns the TRAC OFF light
on/off.
When the TRAC control switch is pressed, the TRAC control does not operate and the TRAC OFF light comes
on.
The skid control ECU connected to the combination meter via CAN and MPX communications.
Tester ConnectionSpecified Condition
Terminal a - Terminal bBelow 1 ohms
Terminal a - Body ground1 Mohms or higher
Tester ConnectionSpecified Condition
Terminal a - Terminal bBelow 1 ohms
Terminal a - Body ground1 Mohms or higher