2003 LEXUS LS430 steering

When there is a malfunction in the contact point of the terminals or installation problems with parts,
removal and installation of the suspected problem parts may return the system to the normal condition
either completely or temporarily.
In order to determine the malfunctioning area, be sure to check the conditions at the time the malfunction
occurred, such as by DTC output and the freeze frame data output, and record it before disconnecting
each connector or removing and installing parts.
Since the ABS with EBD & BA & TRAC & VSC systems may be influenced by a malfunction in the
other systems, be sure to check for DTCs in the other systems.
Be sure to remove and install the skid control ECU, ABS & TRAC actuator and each sensor with the IG
switch OFF unless specified in the inspection procedure.
When removing and installing the skid control ECU, ABS & TRAC actuator and each sensor, be sure to
check that the normal display is output in test mode inspection and in DTC output inspection after
installing all the parts.
After replacing the yaw rate sensor and/or the brake actuator assembly, make sure to perform yaw rate
sensor and deceleration sensor zero point calibration.
(see CALIBRATION
)
CAN communication system is used for the data communication between the skid control ECU (included
in the actuator), the steering angle sensor, and the yaw rate sensor (the deceleration sensor is included). If
there is trouble in the CAN communication line, the DTC in the communication line is output.
If the DTC in the CAN communication line is output, repair the malfunction in the communication line
and troubleshoot the ABS with EBD & BA & TRAC & VSC systems under the condition that data
communication is normal.
Since the CAN communication line has its own length and route, it can not be repaired temporarily with
the bypass wire, etc.
SYSTEM NAME REFERENCE
System NameSee Procedure
Front Power Seat Control SystemINITIALIZATION

Fig. 8: ABS & TRACTION Actuator - Vehicle Stability Control
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Operation description
The skid control ECU determines vehicle condition by receiving signals from the speed sensor, yaw rate
and deceleration sensor and steering angle sensor. The skid control ECU controls engine torque with the
ECM, vehicle position with suspension control ECU via CAN communication, and oil pressure with the
pump and solenoid valve. The warning light comes on and the buzzer sounds when the system is
operating.
2.ABS with EBD & BA & TRAC & VSC OPERATION
a. Skid control ECU calculates vehicle stability tendency based on the signal of sensors, speed sensor,
yaw rate and deceleration sensor and steering angle sensor. And it judges whether the control of
engine output torque by electronic control throttle and of wheel brake pressure by brake actuator
will operate or not by the calculation results.
b. The SLIP indicator blinks and the VSC buzzer sounds to inform the driver that the VSC system is
operating. The SLIP indicator also blinks when TRAC is operating, and the operation being
performed is displayed.
3.FAIL SAFE FUNCTION
a. When a failure occurs in the ABS with BA & TRAC & VSC systems, the ABS warning light and
the VSC warning light turns on and the ABS with BA & TRAC & VSC operations are prohibited.
In addition to this, when there is a failure that disables the EBD operation, the brake warning light
also comes on and the EBD operation is prohibited (see FAIL
-SAFE CHART ).
b. If some control is prohibited due to a malfunction during it's operation, that control will be cut off
gradually not to change stability of vehicle suddenly.
4.PRE-COLLISION BRAKE ASSIST SYSTEM (w/ PRE-COLLISION BRAKE ASSIST SYSTEM)

Fig. 11: Connecting Hand-Held Tester To DLC3
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
MEASUREMENT ITEM / RANGE DESCRIPTION
ItemMeasurement Item / Range (Display)Normal ConditionDiagnostic Note
SPD SEN FRFR speed sensor open detection / OPEN
or NORMALOPEN: Momentary
interruption-
SPD SEN FLFL speed sensor open detection / OPEN
or NORMALOPEN: Momentary
interruption-
SPD SEN RRRR speed sensor open detection / OPEN
or NORMALOPEN: Momentary
interruption-
SPD SEN RLRL speed sensor open detection / OPEN
or NORMALOPEN: Momentary
interruption-
YAWRATE SENYaw rate sensor open detectionOPEN: Momentary
interruption-
DECELE SENG sensor open detectionOPEN: Momentary
interruption-
STEERING SENSteering sensor open detectionOPEN: Momentary
interruption-
M/C SEN 1Master Cylinder pressure sensor 1 open
detectionOPEN: Momentary
interruption-
EFI COMEFI communication open detectionOPEN: Momentary
interruption-

2. Turn the ignition switch to the ON position.
3. Operate the hand-held tester to erase the codes.
HINT:
Refer to the hand-held tester operator's manual for further details.
Check if "VSC" is displayed on the multi-information display.
3.PERFORM ZERO POINT CALIBRATION OF YAW RATE SENSOR AND DECELERATION
SENSOR
a. Check that the steering wheel is in the straight-ahead position and move the shift lever to the P
position.
b. Connect the hand-held tester to the DLC3.
c. Turn the ignition switch to the ON position.
d. Operate the hand-held tester to test mode.
e. Obtain the zero point of the yaw rate sensor and deceleration sensor:
1. Keep the vehicle in the stationar
y condition on a level surface for 2 seconds or more.

sensor check function will be erased.
<002700580055004c0051004a0003005700480056005700030050005200470048000f00030028002600380003005500480046005200550047005600030044004f004f0003002700370026000300520049000300560048005100560052005500030046004b00
480046004e000300490058005100460057004c005200510011[ By preforming sensor signal
check, the codes are erased if normality is confirmed. The codes left over are the codes where
abnormality was found.
a. PROCEDURES FOR TEST MODE
1. Turn the ignition switch off.
2. Connect the hand-held tester to the DLC3.
3. Check that the steering wheel is in the straight-ahead position and move the shift lever to the
P position.
4. Turn the ignition switch to the ON position.
Fig. 20: Connecting Hand
-Held Tester To DLC3
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Fig. 23: Vehicle Speed Graph
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
d. YAW RATE SENSOR CHECK
1. Shift the shift lever to the D range and drive the vehicle at the vehicle speed of approx. 3 mph
(5 km/h), turn the steering wheel either to left or right 90° or more, and maintain 180°
circular drive for the vehicle.

HINT:
If a malfunction code is displayed during the DTC check, check the circuit indicated by the table below.
DIAGNOSTIC TROUBLE CODE CHART
SMF (BA-SOL)Turns TRAC solenoid SMF (BA-SOL)
ON / OFFOperation of solenoid (clicking sound)
can be heard
SMRTurns TRAC solenoid SMR ON / OFFOperation of solenoid (clicking sound)
can be heard
SOL RELAYTurns ABS solenoid relay ON / OFFOperation of solenoid (clicking sound)
can be heard
ABS MOT RELAYTurns ABS motor relay ON / OFFOperation of solenoid (clicking sound)
can be heard
ABS WARN LIGHTTurns ABS warning light ON / OFFObserve combination meter
VSC WARN LIGHTTurns VSC warning light ON / OFFObserve combination meter
VSC / TRC OFF INDTurns VSC / TRC OFF indicator ON /
OFFObserve combination meter
SLIP INDI LIGHTTurns SLIP indicator light ON / OFFObserve combination meter
BRAKE WRN LIGHTTurns BRAKE warning light ON / OFFObserve combination meter
VSC / BR WARN
BUZTurns VSC / BRAKE warning buzzer
ON / OFFBuzzer can be heard
STP LIGHT RELAYTurns stop light ON / OFFStop light come on
DTCDescription
DTC C0200/31, C0205/32RIGHT/LEFT FRONT SPEED SENSOR
DTC C0210/33, C0215/34RIGHT/LEFT REAR SPEED SENSOR
DTC C0226/21, C0236/22, C0246/23,
C0256/24, C1225/25
SFR/SFL/SRR/SRL/SM SOLENOID CIRCUIT
DTC C0273/13, C0274/14, C1361/91OPEN CIRCUIT IN ABS MOTOR RELAY CIRCUIT,
B+ SHORT CIRCUIT IN ABS MOTOR RELAY
CIRCUIT, SHORT CIRCUIT IN ABS MOTOR FAIL
SAFE RELAY CIRCUIT
DTC C0278/11, C0279/12OPEN/SHORT CIRCUIT IN ABS SOLENOID
RELAY CIRCUIT
DTC C1201/51ENGINE CONTROL SYSTEM MALFUNCTION
DTC C1203/53ECM COMMUNICATION CIRCUIT
MALFUNCTION
DTC C1210/36, C1336/39ZERO POINT CALIBRATION OF YAW
RATE/DECELERATION SENSOR UNDONE
DTC C1223/43ABS CONTROL SYSTEM MALFUNCTION
DTC C1231/31MALFUNCTION IN STEERING ANGLE SENSOR
CIRCUIT

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