2003 LEXUS LS430 actuator

Fig. 47: Normal Signal Waveform
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
4.INSPECT FRONT SPEED SENSOR

As the vehicle speed (Wheel revolution speed) increases, a cycle of the waveform narrows and the
fluctuation in the output voltage becomes greater.
When noise is identified in the waveform on the oscilloscope, error signals are generated due to the
speed sensor rotor's scratches, looseness or foreign matter attached to it.
NG: Go to step 7
Fig. 51: Normal Signal Waveform

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
7.INSPECT FRONT SPEED SENSOR INSTALLATION
a. Check the speed sensor installation.
OK: Go to next step

There is no clearance between the sensor and the front steering knuckle.
NG: REPLACE FRONT SPEED SENSOR
Fig. 52: Inspecting Front Speed Sensor Gap

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION

fluctuation in the output voltage becomes greater.
When noise is identified in the waveform on the oscilloscope, error signals are generated due to the
speed sensor rotor's scratches, looseness or foreign matter attached to it.
NG: Go to step 7
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
4.INSPECT REAR SPEED SENSOR
Fig. 56: Inspecting Rear Speed Sensor

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
a. Remove the rear seat cushion and seatback.
b. Make sure that the speed sensor connector and the wire harness side connector are securely
connected.
c. Disconnect the speed sensor connector.
d. Measure the resistance accordin
g to the value (s) in the table below.

OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT )
7.INSPECT REAR SPEED SENSOR INSTALLATION
Fig. 59: Inspecting Rear Speed Sensor Gap

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
a. Check the sensor installation.
OK: Go to next step
There is no clearance between the sensor and rear axle carrier.
The installation bolt is tightened properly.
Torque: 8.0 N.m (82 kgf.cm, 71 in..lbf)

NG: REPLACE REAR SPEED SENSOR
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
<0037004b004c0056000300560052004f004800510052004c00470003005700580055005100560003005200510003005a004b0048005100030056004c004a00510044004f0056000300440055004800030055004800460048004c0059004800470003004900
550052005000030057004b0048000300280026003800030044[nd controls the pressure acting on the wheel
c
ylinders to control the braking force.

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)
<0057005800550051005600030057004b00480003002400250036000300500052005700520055000300550048004f0044005c0003005200510003005700520003005200530048005500440057004800030057004b0048000300440046005700580044005700
52005500030053005800500053000300500052005700520055[.
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.