2003 LEXUS LS430 steering wheel

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)

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.

When U0121/94, U0123/62, U0124/95 or U0126/63 are output together with C1231/31, inspect and
repair the trouble areas indicated by U0121/94, U0123/62, U0124/95 or U0126/63 first.
When the speed sensor or the yaw rate sensor has trouble, DTCs for the steering angle sensor may be
output even when the steering angle sensor is normal. When DTCs for the speed sensor or yaw rate
sensor are output together with other DTCs for the steering angle sensor, inspect and repair the speed
sensor and yaw rate sensor first, and then inspect and repair the steering angle sensor.
1.CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)
a. Using the hand-held tester, check for any momentary interruption in the wire harness and
connectors between the skid control ECU and steering angle sensor (see CHECK FOR
INTERMITTENT PROBLEMS ).
MEASUREMENT ITEM / RANGE (DISPLAY) DESCRIPTION
OK: Go to next step
There are no momentary interruptions.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (SKID CONTROL ECU -
STEERING ANGLE SENSOR)
OK: Go to next step
2.READ VALUE OF HAND-HELD TESTER (STEERING ANGLE SENSOR VALUE)
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. 77: DATA LIST Mode Description

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
d. Check that the steering angle sensor value of the steering angle sensor observed in the hand-held
tester changes when the steering wheel is moved.
OK: Go to next step
Steering angle value changes.
ItemMeasurement Item / Range (Display)Normal Condition
STEERING SENSteering sensor open detectionOPEN: Momentary interruption

NG: Go to step 3
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
3.CHECK TERMINAL VOLTAGE (STEERING ANGLE SENSOR CONNECTOR)
a. Remove the steering wheel and the column lower cover.
b. Disconnect the steering angle sensor connector.
c. Turn the ignition switch to the ON position.
d. Measure the voltage according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
e. Measure the voltage according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION
Tester ConnectionSpecified Condition
S16-1 (IG1) - S16-2 (ESS)10 to 14V
Tester ConnectionSpecified Condition
S16-3 (BAT) -S16-2 (ESS)10 to 14V

If the vehicle is raised with its engine running, connect terminals OPB and CG of the DLC3 to stop
the vehicle height control operation of the suspension control ECU.
Do not operate the steering wheel if there is no air in the pneumatic cylinder.
HINT:
The pneumatic cylinder could be damaged if twisted without air in the cylinder.
In the case of lifting down the vehicle without air in the cylinder, make sure all the pipes are securely
connected.
HINT:
The pneumatic cylinder could be damaged if any pipe is disconnected while lifting down the vehicle.
Do not apply battery voltage to the compressor motor for more than 60 seconds to prevent damage to the
motor.
HINT:
When it is necessary to perform the operation by charging the battery for more than 60 seconds, for example
height recovery without air in the cylinder, proceed to the operation as follows: after 60 seconds have passed,
turn the ignition switch off once, and then turn the ignition switch to the ON position again for commencement
of operation.

b. Turn the ignition switch to the ON position and turn the hand-held tester main switch on.
c. Select the item below in the DATA LIST and read its value displayed on the hand-held tester.
AIR SUS:
Fig. 125: Data List Value Description

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
d. Check that the steering wheel turning angle value of the steering angle position sensor displayed on
the hand-held tester changes when turning the steering wheel.
Standard:
Steering wheel turning angle value changes.
NG: Go to step 2
OK: REPLACE SUSPENSION CONTROL ECU (SEE REPLACEMENT
)
2.CHECK DIAGNOSTIC CODE OUTPUT
a. Check if the normal system code is output in the CAN communication system (SEE
SUSPENSION CONTROL ECU COMMUNICATION STOP MODE
).
OK:
No DTC is output in the CAN communication system.
NG: REPAIR CIRCUIT INDICATED BY OUTPUT CODE
OK:Go to next step
3.CHECK HARNESS AND CONNECTOR (STEERING SENSOR POWER SOURCE)
a. Disconnect the steering sensor S16 connector.
b. Turn the ignition switch to the ON position.
c. Measure the voltage according to the value (s) in the table below.
TESTER CONNECTION STANDARD SPECIFIED CONDITION
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
Tester ConnectionSpecified Condition
S16-1 (IG1) - S16-2 (ESS)10 to 14 V
S16-3 (BAT) - S16-2 (ESS)10 to 14 V