2003 LEXUS LS430 relay

NG: CHECK FOR SHORT IN ALL HARNESS AND CONNECTOR CONNECTED TO FUSE
AND REPLACE FUSE
OK: Go to next step
3.CHECK TERMINAL VOLTAGE (ABS MOTOR RELAY 5 TERMINAL OF ENGINE ROOM
NO.3 R/B)
a. Remove the ABS MTR relay from the engine room No.3 R/B.
b. Turn the ignition switch to the ON position.
c. Measure the voltage according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
Fig. 65: Identifying ABS MTR Relay Location
Tester ConnectionSpecified Condition
Terminals 5 - Body ground10 to 14V

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NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go to next step
4.INSPECT ABS MOTOR RELAY
a. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
Fig. 66: Inspecting ABS Motor Relay

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NG: REPLACE ABS MOTOR RELAY
OK: Go to next step
5.INSPECT ABS CUT RELAY
Tester ConnectionConnectionSpecified resistance
3-5Always1 Mohms or higher (No continuity)
3-5Apply B+ between terminal 1 and 2Below 1 ohms

a. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
NO: REPLACE ABS CUT RELAY
Fig. 67: Inspecting ABS Cut Relay

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OK: Go to next step
6.CHECK HARNESS AND CONNECTOR (ABS MOTOR RELAY - ABS CUT RELAY)
a. Remove the ABS motor relay and ABS cut relay from engine room R/B.
b. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
Tester ConnectionConnectionSpecified resistance
3 - 5Always1 Mohms or higher (No continuity)
3 - 5Apply B+ between terminal 1 and 2Below 1 ohms

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go to next step
7.CHECK HARNESS AND CONNECTOR (ABS MOTOR RELAY - SKID CONTROL ECU)
a. Disconnect the skid control ECU connector.
b. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
c. Measure the resistance accordin
g to the value (s) in the table below.
Tester ConnectionSpecified Condition
5 (ABS MOTOR Relay) - 3 (ABS cut relay)Below 1 ohms
Tester ConnectionSpecified Condition
S42-2 (BM) - 3 (Engine room R/B)Below 1 ohms

Fig. 68: Identifying ABS Motor Relay Location
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
Tester ConnectionSpecified Condition
S42-2 (BM) - Body ground1 Mohms or higher

Fig. 69: Identifying Skid Control ECU Connector Terminals
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NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
The ABS solenoid relay is built in the ABS & TRACTION Actuator assy. This relay supplies power to each
ABS solenoid. If the initial check is OK, after the ignition switch is turned to the ON position, the relay stays
on.
Fig. 70: DTC C0278/11 And DTC C0279/12 Detecting Condition And Trouble Area

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WIRING DIAGRAM

Fig. 71: ABS Solenoid Relay Wiring Diagram
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INSPECTION PROCEDURE
1.INSPECT FUSE (ABS1 FUSE)
a. Remove the ABS 1 fuse from the fusible link block.
b. Measure the resistance according to the value (s) in the table below.
Standard:
ABS 1 FUSE DESCRIPTION
ABS 1 fuseBelow 1 ohms (Continuity)

Fig. 73: Identifying SKID Control ECU Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
3.RECONFIRM DTC
HINT:
This code is detected when a problem is determined in the brake actuator assy. The ABS solenoid circuit
is in the brake actuator assy. Therefore, solenoid circuit inspection relay unit inspection cannot be
performed. Be sure to check if the DTC code is output before replacing the brake actuator assy.
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.
OK: Go to next step
The same DTC is recorded.
NG: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE