2003 LEXUS LS430 Identifying ac

Fig. 106: Identifying Skid Control ECU Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
The brake pedal load sensing switch is turned on when the brake pedal is depressed with force exceeding a
predetermined level.
The skid control ECU detects if the brake pedal is depressed or not via this circuit.

Fig. 111: Identifying Skid Control ECU Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION

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. 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

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
Fig. 123: Identifying Skid Control ECU Terminals

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: Go to next step
6.INSPECT BRAKE FLUID LEVEL WARNING SWITCH
a. Remove the reservoir tank cap and strainer.
S42-28 (PKB) - Body ground1M ohms or higher

b. Disconnect the brake fluid level warning switch connector.
c. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
NG: REPLACE BRAKE FLUID LEVEL WARNING SWITCH
Fig. 124: Identifying Brake Fluid Level Warning Switch Terminals

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: Go to next step
7.CHECK HARNESS OR CONNECTOR (BRAKE FLUID LEVEL WARNING SWITCH SKID
CONTROL ECU)
Tester ConnectionSwitch ConditionSpecified Condition
(B1-1) - (B1-2)Float UP1M ohms or higher
(B1-1) - (B1-2)Float DOWNBelow 1 ohms

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

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