2003 LEXUS LS430 Diagram AC

Fig. 95: Identifying Skid Control ECU Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
CIRCUIT DESCRIPTION
Recognition of brake operation by sending stop lamp signal to skid control ECU.
Fig. 96: DTC C1249/49 Detecting Condition And Trouble Area

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
WIRING DIAGRAM

Fig. 97: Stop Light Switch Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.CHECK STOP LAMP SWITCH OPERATION
a. Check that the stop light comes on when the brake pedal is depressed and turns off when the brake
pedal is released.
OK:

OK: Go to next step
9.RECONFIRM DTC
a. Clear the DTC (see DTC CHECK/CLEAR
).
b. Turn the ignition switch to the ON position.
c. Check that the same DTC is recorded (see DTC CHECK/CLEAR
).
OK:
The same DTC is recorded.
NG: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
ABS pump motor is located inside the brake actuator. The motor is used for BA, TRAC and VSC operation.
Fig. 104: DTC C1251/51 Detection Condition And Trouble Area Description Chart

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
WIRING DIAGRAM

Fig. 105: Pump Motor Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.PERFORM ACTIVE TEST BY HAND-HELD TESTER (ABS MOTOR RELAY OPERATION)
a. Connect the hand-held tester to the DLC3.
b. Start the engine.
c. Select the ACTIVE TEST mode on the hand-held tester.
d. Check the operation sound of the ABS motor individually when operating it with the hand-held
tester.

Fig. 107: DTC C1267/67 Detection Condition And Trouble Area Description Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
WIRING DIAGRAM
Fig. 108: Brake Pedal Load Sensing Switch Wiring Diagram

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.READ VALUE OF HAND-HELD TESTER
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. 109: DATA LIST Mode Description

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During DTC read by SST (Check Wire), if the ABS warning light remains on, trouble shoot by following this
inspection flow.
WIRING DIAGRAM
Fig. 112: ABS Warning Light Wiring Diagram

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

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

Fig. 115: ABS Warning Light Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.INSPECT CAN COMMUNICATION SYSTEM