2003 LEXUS LS430 engine

corresponding to a DTC (see CHECK FOR INTERMITTENT PROBLEMS ).
MEASUREMENT ITEM / RANGE (DISPLAY) DESCRIPTION
OK: Go to next step
There are no momentary interruption.
HINT:
Perform the above inspection before removing the sensor and connector.
NG: Go to step 5
OK: Go to next step
2.READ VALUE OF HAND-HELD TESTER (REAR SPEED SENSOR)
a. Connect the hand-held tester to the DLC3.
b. Start the engine.
c. Select the DATA LIST mode on the hand-held tester.
MEASUREMENT ITEM / RANGE (DISPLAY) DESCRIPTION
d. Check that there is no difference between the speed value output from the speed sensor displayed
by the hand-held tester and the speed value displayed on the speedometer when driving the vehicle.
OK: Go to next step
There is almost no difference in the displayed speed value.
HINT:
There is tolerance of 10 % in the speedometer indication.
ItemMeasurement Item / Range (Display)Normal Condition
SPD SEN RRRR speed sensor open detection / OPEN or
NORMALOPEN: Momentary interruption
SPD SEN RLRL speed sensor open detection / OPEN or
NORMALOPEN: Momentary interruption
ItemMeasurement Item / Range (Display)
Normal
Condition
WHEEL SPD RLWheel speed sensor (RL) reading / min.: 0 km/h (0 MPH,
max.: 326 km/h (202 MPH)Actual wheel
speed
WHEEL SPD RRWheel speed sensor (RR) reading / min.: 0 km/h (0 MPH,
max.: 326 km/h (202 MPH)Actual wheel
speed

Fig. 61: SFL Solenoid Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.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. Start the engine.
c. Drive the vehicle at the speed of 4 mph (6 km/h) or more.
d. 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
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
The ABS motor relays consist of 2 relays are included in the engine room No.3 R/B.
The ABS cut relay is turned on after turning the ignition switch to the ON position. If the DTCs in the
ABS pump motor circuit are memorized, the ABS cut relay cuts off the power supply to the ABS motor
relay and performs the fail safe.
While any of the ABS, BA, TRAC and VSC is operating, the skid control ECU (included in the actuator)
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If the voltage applied to the ABS motor relays (+BM) drops below the condition that detects the DTCs
due to the shorta
ge of the battery or alternator output, the DTCs may be memorized.

Fig. 63: ABS Motor Relay 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.

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

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

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

HINT:
It is suspect that the DTCs output was caused by the poor connection on the connector terminal.
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
If trouble occurs in the engine control system, the ECM transmits the abnormality to the skid control ECU. The
skid control ECU sets this DTC and the skid control ECU prohibits TRAC and VSC control.
DTC DETECTING CONDITION DESCRIPTION
INSPECTION PROCEDURE
1.CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)
a. Using the hand-held tester, check for any momentary interruption in the wire harness and connector
corresponding to a DTC (see CHECK FOR INTERMITTENT PROBLEMS
).
MEASUREMENT ITEM / RANGE (DISPLAY) DESCRIPTION
OK: Go to next step
There are no momentary interruptions.
HINT:
Perform the above inspection before removing the sensor and connector.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - SKID CONTROL ECU)
OK: Go to next step
2.CHECK DTC FOR ENGINE
a. Check if the normal code is recorded for en
gine control system.
DTC No.DTC Detecting ConditionTrouble Area
C1201/51At the engine speed of 500 RPM, a trouble signal in the engine
control system continues for 5 secs, or more.Engine control
system
ItemMeasurement Item / Range (Display)Normal Condition
EFI COMEFI communication open detectionOPEN: Momentary interruption