2003 LEXUS LS430 warning light

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. 17: Identifying VSC Test
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
2. Check that the display changes to "VSC Test" on the multi-information display.
HINT:
"VSC" is displayed while obtaining the zero point. "VSC Test" is displayed when it is
completed.
The zero point calibration is performed only once after the system enters the test mode.
Calibration cannot be performed again until the stored data is cleared once.
f. Turn the ignition switch off.
1.WARNING LIGHT AND INDICATOR LIGHT CHECK
a. Release the parking brake pedal.

HINT:
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57004b00480003004500550044004e004800030049004f0058[id is low, the BRAKE warning light
comes on.
b. When the ignition switch is turned to the ON position, check that the ABS warning light, TRAC
OFF indicator light, BRAKE warning light and SLIP indicator light come on for approximately 3
seconds.
HINT:
If the ECU was any stored DTCs, the ABS warning light, "VSC" is displayed on the multi-
information display and TRAC OFF indicator light come on.
If the indicator does not come on, inspect it the bulb is blown out, and also the wire harness
between the skid control ECU and the combination meter.

Fig. 18: Identifying Warning Light And Indicator Light
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Fig. 19: Identifying VSC Location
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
If the indicator remains on, proceed to troubleshooting for the light circuit below.
TROUBLE AREA REFERENCE
2.SENSOR SIGNAL CHECK BY TEST MODE
HINT:
If the ignition switch is turned from ON to the ACC or LOCK position during test mode, DTC of
Trouble areaSee Procedure
ABS warning light circuitABS WARNING LIGHT CIRCUIT (REMAINS ON)
BRAKE warning light circuitBRAKE WARNING LIGHT CIRCUIT
TRAC OFF indicator light
circuitTRAC OFF INDICATOR LIGHT, TRAC OFF SWITCH
CIRCUIT
SLIP indicator light circuitSLIP INDICATOR LIGHT CIRCUIT

Fig. 21: ABS Warning Light Blinking Pattern
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
5. Check that the ABS warning light blinking TEST MODE and "VSC Test" is displayed on the
multi-information display.
HINT:
If the ABS warning light and VSC information do not blink, inspect the ABS warning light
circuit and VSC warning information circuit.
TROUBLE AREA REFERENCE
6. Start the engine.
b. DECELERATION SENSOR CHECK
1. Check that the ABS warning lamp is blinking in TEST MODE.
2. Keep the vehicle in the stationar
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110003[
Trouble areaSee Procedure
ABS warning light circuitABS WARNING LIGHT CIRCUIT (DOES NOT
LIGHT UP)
VSC warning information
circuitVSC WARNING LIGHT CIRCUIT (DOES NOT
LIGHT UP)

HINT:
The blinking pattern of the ABS warning lamp and the "VSC Test" display on the multi-
information do not change. When the sensor is normal and in the test mode, if the above conditions
are met, the check is completed.
Fig. 22: Identifying VSC Test Location

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
c. CHECK THE MASTER CYLINDER PRESSURE SENSOR
1. Leaving the vehicle in a stationary condition engine is off and the brake pedal in a free
condition for 1 second. or more, continue to quickly depress the brake pedal with a force of
98 N (10 kgf, 22 lbf) or more for 1 second, or more.
HINT:
At this time, the ABS warnin
g light stays on for 3 seconds.

2. Drive the vehicle straight forward.
Drive the vehicle at a speed of 28 to 50 mph (45 to 80 km/h) or higher for several seconds and
check that the ABS warning light goes off.
Fig. 25: Identifying ABS Warning Light Blinking Pattern

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
VEHICLE SPEED SPECIFICATIONS
HINT:
Vehicle SpeedTestCheck
0 to 28 mph (0 to 45 km/h)Low speed testResponse of sensors
28 to 50 mph (45 to 80 km/h)Middle speed testDeviations of sensor signal