2003 LEXUS LS430 Control actuator

HINT:
*3 is OK, but *1 is NG --> ECM failure
*1 is OK, but *2 is NG --> DTC output or ECM failure
*3 is OK, but CRUISE main indicator light does not come on --> Indicator, W/H, or ECM failure
MULTI-INFORMATION DISPLAY CONTROL SWITCH (STEERING PAD SWITCH
MODULATOR):
DATA LIST (MULTI-INFORMATION DISPLAY CONTROL SWITCH (STEERING PAD
SWITCH MODULATOR))
2.ACTIVE TEST
HINT:
Performing the ACTIVE TEST using the hand-held tester allows components such as the relay, VSV, and
actuator to operate without parts removal. Performing the ACTIVE TEST as the first step of
troubleshooting is one way to shorten labor time.
It is possible to display the DATA LIST during the ACTIVE TEST.
a. Connect the hand-held tester to the DLC3.
b. Turn the ignition switch to the ON position.
c. According to the display on the tester, perform the "ACTIVE TEST".
HINT:
The ignition switch must be turned to the ON position to proceed to the ACTIVE TEST using the hand-
held tester.
COMBINATION METER ASSY:
ACTIVE TEST DETAIL (COMBINATION METER ASSY)
VSC FAIL SAFEVSC fail-safe flag/ON or
OFF--
ItemMeasurement Item / Display
(Range)Normal ConditionDiagnostic
Note
MULTI
DSP2 SWSteering pad switch (DISP2)
signal / ON or OFFON <=> OFF: Change ON/OFF each time
steering pad switch (DISP2) SW is pushed.-
ItemVehicle Condition / Test DetailsDiagnostic Note
CRUISE INDIC"CRUISE" indicator is ON / OFF-

Fig. 53: DTC P1631 And U0100 Problem Symptom Diagnostic Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
HINT:
This circuit uses CAN for communication. Therefore, if there are any malfunctions in the communication
circuit, one or more DTCs in the CAN communication system is/are output.
1.GO TO CAN COMMUNICATION SYSTEM (SEE HOW TO PROCEED WITH
TROUBLESHOOTING )
CIRCUIT DESCRIPTION
The ABS & traction actuator assy (skid control ECU) receives the alarm demand signal from the ECM and
operates the skid control buzzer.
The buzzer sounds to warn that the distance between the vehicle in front and your own vehicle is shortening.
Fig. 54: DTC P1575 Problem Symptom Diagnostic
Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
HINT:
If the vehicle ahead in the same lane significantly decreases its speed or another vehicle pulls in front of your
own vehicle, adequate deceleration cannot be applied and the vehicle-to-vehicle distance will shorten. At this
time, the s
ystem sounds the buzzer and the master warning light blinks to inform the driver.

CIRCUIT DESCRIPTION
When the cruise control main switch is on, CRUISE main indicator light and READY indicator light come on.
This indicates the control condition (presence or absence of a vehicle in front, vehicle-to-vehicle distance, and
set vehicle speed) and fail-safe state through the multiplex communication system and CAN communication
system.
The master warning light and, CRUISE main indicator light come on and vehicle-to-vehicle distance
information is displayed on the combination meter as the alarm buzzer sounds.
Items such as "Clean Radar Sensor", "Cruise not Available", "Check Cruise System" and "Radar Cruise Ready"
are displayed in the multi-information display on the combination meter when the ECM detects signals from
each sensor and actuator and sends them to the combination meter via CAN and BEAN.
HINT:
If the vehicle in front in the same lane significantly decreases vehicle speed or another vehicle pulls in front of
your vehicle, adequate deceleration cannot be applied and the vehicle-to-vehicle distance will shorten. At this
time, the system sounds the buzzer and the master warning light blinks to warn the driver.
Each indicator in the dynamic laser cruise control uses CAN and BEAN for communication. Therefore if there
are any malfunctions in this circuit, check for DTCs in the CAN communication and multiplex communication
systems.
INSPECTION PROCEDURE
1.PERFORM ACTIVE TEST BY HAND-HELD TESTER
a. Connect the hand-held tester to the DLC3.
b. Check the cruise control switch by using ACTIVE TEST.
COMBINATION METER:
ACTIVE TEST DETAIL (COMBINATION METER)
OK: Indicator light comes on.
NG: GO TO COMBINATION METER SYSTEM (SEE HOW TO PROCEED WITH
TROUBLESHOOTING )
DescriptionTester displayCheck condition
"CRUISE" indicator is ON / OFFCRUISE INDICON - OFF
Graphic area is ON / OFFL-CRUISE DISPON - OFF
"CHECK CRUISE SYSTEM" indicator is
ON / OFFL-CRS CHECK INDON - OFF
"RADAR READY" indicator is ON / OFFL-CRS READY INDON - OFF

1.GENERAL
a. The dynamic radar cruise control system has two cruise control modes: the constant speed control
mode and vehicle-to-vehicle distance control mode.
The vehicle-to-vehicle distance control mode is always selected when starting up the
dynamic radar cruise control system.
Operation of the constant speed control mode is the same as that for the conventional type
cruise control system.
b. This system maintains the vehicle running at the speed that the driver has set, as long as there are
no vehicles ahead in the same lane. Then, the system maintains the vehicle distance that has been
set by the driver.
If the system detects a vehicle moving at a slower speed ahead while the driver is driving at a
constant speed, it closes the throttle valve to decelerate. If further deceleration is required, the
system controls the brake actuator in order to apply the brakes. Thereafter, if there are no vehicles
ahead within the set vehicle-to-vehicle distance because either the vehicle ahead or the driver has
changed lanes, the system accelerates slowly to reach the set vehicle speed and resumes driving at
the constant speed.
c. The constant speed control mode is designed to maintain a constant cruising speed. The vehicle-to-
vehicle distance control mode is designed to control cruising at a constant speed function,
deceleration cruising function, follow-up cruising function and acceleration cruising function.
d. The millimeter wave radar sensor and the distance control ECU (cruise control ECU) control the
system while the vehicle-to-vehicle distance control mode is in operation, and send signals to each
actuator and ECU.
e. In vehicle-to-vehicle distance control mode, the dynamic radar cruise control system receives
signals from the yaw rate & deceleration sensor and the steering angle sensor. Based on these
signals, it then estimates curve radius and compensates for information on the preceding vehicle
while turning. It can also compensate for the brake control when approaching another vehicle.
f. This system judges the existence of a vehicle in front and the distance to it based on the signals
from the radar sensor while the vehicle-to-vehicle distance control mode is in operation. Using this
information, the system informs the driver of any danger with the warning buzzer, performs brake
control, and turns on the stop lamp when approaching the vehicle in front.
g. The following illustration shows a control example under the following conditions: own vehicle
speed is 100 km/h (62 mph) and the speed of the vehicle in front is 80 km/h (50 mph).

Fig. 42: Data List Chart - CC (ECM) (2 Of 2)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
MULTI-INFORMATION DISPLAY CONTROL SWITCH (STEERING PAD SWITCH
MODULATOR):
DATA LIST (MULTI-INFORMATION DISPLAY CONTROL SWITCH (STEERING PAD
SWITCH MODULATOR))
2.ACTIVE TEST
HINT:
Performing the ACTIVE TEST using the hand-held tester allows components such as the relay, VSV, and
actuator to operate without parts removal. Performing the ACTIVE TEST as the first step of
troubleshooting is one way to shorten labor time.
It is possible to displa
y the DATA LIST during the ACTIVE TEST.
Item
Measurement Item / Display
(Range)
Normal ConditionDiagnostic Note
MULTI DSP2
SWSteering pad switch (DISP2)
signal / ON or OFFON <=> OFF: Change ON/OFF
each time steering pad switch
(DISP2) SW is pushed.-

CIRCUIT DESCRIPTION
The ECM sends signals such as A/T information signal, dynamic radar cruise control operation signal, brake
operation demand signal, buzzer operation demand signal and low speed mode signal, etc. to the skid control
ECU when the dynamic radar cruise control is in operation.
<0037004b004800030028002600300003004c005600030057004b0048000300520051004f005c000300460052005000530052005100480051005700030057004b004400570003004b0044005600030044000300490058005100460057004c00520051000300
57005200030055004800460052005500470003004400510047[ output the DTCs in the dynamic radar cruise
control system. Therefore if the skid control ECU detects a communication error from the ECM, it sends the
malfunction signal back to the ECM.
Fig. 56: DTC P1631 And U0100 Problem Symptom Diagnostic Chart

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
HINT:
This circuit uses CAN for communication. Therefore, if there are any malfunctions in the communication
circuit, one or more DTCs in the CAN communication system is/are output.
1.GO TO CAN COMMUNICATION SYSTEM (SEE PRECAUTION
)
CIRCUIT DESCRIPTION
The ABS & traction actuator assy (skid control ECU) receives the alarm demand signal from the ECM and
operates the skid control buzzer.
The buzzer sounds to warn that the distance between the vehicle in front and
your own vehicle is shortening.

CIRCUIT DESCRIPTION
When the cruise control main switch is on, CRUISE main indicator light and READY indicator light come on.
This indicates the control condition (presence or absence of a vehicle in front, vehicle-to-vehicle distance, and
set vehicle speed) and fail-safe state through the multiplex communication system and CAN communication
system.
The master warning light and CRUISE main indicator light come on and vehicle-to-vehicle distance
information is displayed on the combination meter as the alarm buzzer sounds.
Items such as "Clean Radar Sensor", "Cruise not Available", "Check Cruise System" and "Radar Cruise Ready"
are displayed in the multi-information display on the combination meter when the ECM detects signals from
each sensor and actuator and sends them to the combination meter via CAN and BEAN.
HINT:
If the vehicle in front in the same lane significantly decreases vehicle speed or another vehicle pulls in front of
your vehicle, adequate deceleration cannot be applied and the vehicle-to-vehicle distance will shorten. At this
time, the system sounds the buzzer and the master warning light blinks to warn the driver.
Each indicator in the dynamic laser cruise control uses CAN and BEAN for communication. Therefore if there
are any malfunctions in this circuit, check for DTCs in the CAN communication and multiplex communication
systems.
INSPECTION PROCEDURE
1.PERFORM ACTIVE TEST BY HAND-HELD TESTER
a. Connect the hand-held tester to the DLC3.
b. Check the cruise control switch by using ACTIVE TEST.
COMBINATION METER:
ACTIVE TEST DETAIL (COMBINATION METER)
OK: Indicator light comes on.
NG: GO TO COMBINATION METER SYSTEM (SEE HOW TO PROCEED WITH
TROUBLESHOOTING )
DescriptionTester displayCheck condition
"CRUISE" indicator is ON / OFFCRUISE INDICON - OFF
Graphic area is ON / OFFL-CRUISE DISPON - OFF
"CHECK CRUISE SYSTEM" indicator is ON / OFFL-CRS CHECK INDON - OFF
"RADAR READY" indicator is ON / OFFL-CRS READY INDON - OFF

MOTORS LOCATION
Navigation ECUFig. 4 .
Passenger Side J/B ECUAt right kick panel. See Fig. 17 .
Power Tilt & Power Telescopic ECUBehind left side of dash. See Fig. 17 .
PPS ECURight side of dash. See Fig. 17 .
Rear Door LH ECUInside left rear door. See Fig. 4 .
Rear Door RH ECUInside right rear door. See Fig. 4 .
Rear LH Seat ECUBehind left side of rear seat back. See Fig. 32 .
Rear RH Seat ECUBehind right side of rear seat back. See Fig. 32 .
Seat Belt Control ECULeft side of luggage compartment. See Fig. 4 .
Seat Climate Controller Front LH (Seat Back)In driver's seat back. See Fig. 31 .
Seat Climate Controller Front RH (Seat Back)In passenger's seat back. See Fig. 31 .
Seat Climate Controller Rear LH (Seat Back)In left rear seat back. See Fig. 32 .
Seat Climate Controller Rear LH (Seat Cushion)In left rear seat cushion. See Fig. 32 .
Seat Climate Controller Rear RH (Seat Back)In right rear seat back. See Fig. 32 .
Seat Climate Controller Rear RH (Seat Cushion)In right rear seat cushion. See Fig. 32 .
Shift Lock Control ECUBelow shift lever, in center console. See Fig. 18 .
Skid Control ECU W/ActuatorBehind left side of dash. See Fig. 1 .
Steering Lock ECULeft side of dash. See Fig. 18 .
Stereo Component TunerOn lower right side of luggage compartment. See
Fig. 4
.
Television Camera ECURight rear of luggage compartment. See Fig. 4 .
Theft Deterrent ECUBehind upper right center of dash. See Fig. 18 .
Transponder Key ComputerBehind upper center of dash. See Fig. 18 .
Vibration Seat ECU LHBehind left rear seat back. See Fig. 32 .
Vibration Seat ECU RHIn rear seat assembly. See Fig. 32 .
ComponentLocation
Air Inlet Control Servo MotorRight side of dash. See Fig. 2 .
Air Mix Control Servo Motor (Driver Side)Center of dash. See Fig. 2 .
Air Mix Control Servo Motor (Front Passenger
Side)Right side of dash. See Fig. 2 .
Air Vent Mode Control Servo Motor (Driver Side)Center of dash. See Fig. 2 .
Air Vent Mode Control Servo Motor (Front
Passenger Side)Center of dash. See Fig. 2 .
Blower MotorBehind lower right side of dash. See Fig. 2 .
Cool Air Bypass Servo Motor (Driver's Side)Left side of dash. See Fig. 2 .
Cool Air Bypass Servo Motor (Front Passenger
Side)Right side of dash. See Fig. 2 .
Front Wiper MotorBelow left side of windshield. See Fig. 13 .