LEXUS LS430 2003 Factory Repair Manual

Fig. 125: Identifying Skid Control ECU Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: Go to next step

8.INSPECT PAD WEAR INDICATOR WIRE ASSY
FRONT:
HINT:
Check that there are no scratches or cracks on the pad wear indicator.
a. Remove the front wheel RH.
b. Disconnect front pad wear indicator connector.
c. Measure the resistance accordin
g to the value (s) in the table below.

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

WIRING DIAGRAM
Fig. 127: TRAC Off Indicator Light, TRAC Off Switch Wiring Diagram

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE

1.PERFORM ACTIVE TEST BY HAND-HELD TESTER (TRAC OFF INDICATOR LIGHT)
a. Connect the hand-held tester to the DLC3.
b. Start the engine.
c. Select the item "TRAC OFF LIGHT" in the ACTIVE TEST and operate the TRAC OFF indicator
light on the hand-held tester.
VEHICLE CONDITION / TEST DETAILS
d. Check that "ON" and "OFF" of the TRAC OFF indicator light are indicated on the combination
meter when using the hand-held tester.
OK: Go to next step
Turn the TRAC OFF indicator light on or off in accordance with the hand-held tester.
NG: Go to step 5
OK: 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 CAN COMMUNICATION SYSTEM
a. Is the DTC output for CAN communication system?
Result:
DTC OUTPUT DESCRIPTION
ItemVehicle Condition / Test DetailsDiagnostic Note
VSC / TRAC OFF INDTurns VSC / TRAC OFF indicator ON / OFFObserve combination meter
DTC is not outputA
DTC is outputB
DTC is not outputA
DTC is outputB

B: REPAIR CAN COMMUNICATION SYSTEM (SEE PRECAUTION )
A: Go to next step
4.INSPECT TRACTION CONTROL SWITCH
a. Remove the TRAC control switch.
b. Disconnect the TRAC control switch connector.
c. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
NG: REPLACE TRACTION CONTROL SWITCH
Tester ConnectionSwitch ConditionSpecified Condition
T7-8 (+) - T7-6Pushed in (ON)Below 1 ohms
T7-8 (+) - T7-6Released (OFF)1 Mohms or higher

Fig. 128: Identifying TRAC Control Switch Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: Go to next step
5.CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - TRAC OFF SWITCH)
a. Disconnect the skid control ECU connector and the TRAC control switch connector.
b. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
Tester ConnectionSpecified Condition

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
S42-43 (CSW) - T7-8Below 1 ohms
S42-43 (CSW) - Body ground1 Mohms or higher
T7-6 - Body groundBelow 1 ohms