LEXUS LS430 2003 Factory Repair Manual

OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON PROBLEM SYMPTOMS
TABLE
4.INSPECT SPEED SENSOR TIP
a. Remove the front and rear speed sensor.
b. Check the sensor tip.
OK: Go to next step
No scratches or foreign matter on the sensor tip.
NG: CLEAN OR REPLACE SPEED SENSOR
OK: Go to next step
5.INSPECT SPEED SENSOR ROTOR
a. Remove the front axle hub and front speed sensor rotor.
b. Check the sensor rotor serrations.
OK: Go to next step
No scratches, missing teeth or foreign matter on the rotors.
HINT:
If there is foreign matter in the rotor, remove it and check the output waveform after reassembly.
NG: CLEAN OR REPLACE SPEED SENSOR ROTOR
OK: REPLACE SPEED SENSOR

Fig. 87: Identifying Speed Sensor Rotor Location
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
CIRCUIT DESCRIPTION
Fig. 88: DTC C1241/41 Detecting Condition And Trouble Area

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

Fig. 89: Low Battery Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.INSPECT FUSE (ABS-IG FUSE)
a. Remove the ABS-IG Fuse from the driver side J/B.
b. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
Tester ConnectionSpecified Condition
ABS-IG fuseBelow 1 ohms (Continuity)

Fig. 90: Identifying ABS-IG Fuse Location
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: INSPECT FOR SHORT CIRCUIT IN ALL HARNESS AND COMPONENTS CONNECTED
TO ECU-IG FUSE

OK: Go to next step
2.INSPECT BATTERY
a. Check the battery voltage.
Standard:
Voltage: 10 to 14 V
NG: INSPECT CHARGING SYSTEM (SEE ON
-VEHICLE INSPECTION )
OK: Go to next step
3.INSPECT SKID CONTROL ECU TERMINAL VOLTAGE (IG1 TERMINAL)
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. 91: DATA LIST Mode Description

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d. Read the voltage condition output from the ECU displayed on the hand-held tester.
Standard:
"Normal" is displayed.
NG: Go to step 4
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
4.INSPECT SKID CONTROL ECU CONNECTOR (GND TERMINAL CONTINUITY)
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
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (GND TERMINAL - BODY
GROUND)
Fig. 92: Identifying Skid Control ECU Connector Terminals

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: CHECK AND REPAIR HARNESS AND CONNECTOR (IG1 TERMINAL - BATTERY)
CIRCUIT DESCRIPTION
Master c
ylinder pressure sensor is connected to the skid control ECU in the actuator.
Tester ConnectionSpecified Condition
S42-32 (GND) - Body groundBelow 1ohms

Fig. 93: Master Cylinder Pressure Sensor Circuit Description
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Fig. 94: DTC C1246/46 Detecting Condition And Trouble Area

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.READ VALUE OF HAND-HELD TESTER (MASTER CYLINDER PRESSURE 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 the brake fluid pressure value of the master cylinder pressure sensor observed in the
hand held tester changes when the brake pedal is depressed.
OK: Go to next step
When the pedal is depressed, displayed voltage on the hand-held tester increases.
NG: Go to step 2
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
2.INSPECT SKID CONTROL ECU TERMINAL VOLTAGE (STP TERMINAL)
a. Disconnect the skid control ECU connector.
b. Measure the voltage according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
NG: CHECK AND REPLACE STOP LIGHT SWITCH CIRCUIT
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
ItemMeasurement Item / Range (Display)Normal Condition
MAS CYL PRS
1Master cylinder pressure sensor 1 reading /
min.: 0 V, max.: 5 VWhen brake pedal is released:
0.3 to 0.9V
Tester ConnectionSwitch ConditionSpecified Condition
S42-27 (STP) - Body groundBrake pedal depressed8 to 14V
S42-27 (STP) - Body groundBrake pedal releasedBelow 1 V

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
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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: