2003 LEXUS LS430 light

Fig. 57: 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 system sounds the buzzer and the master warning light blinks to inform the driver.
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.
WIRING DIAGRAM
SEE WIRING DIAGRAM
.
INSPECTION PROCEDURE
SEE INSPECTION PROCEDURE
.
CIRCUIT DESCRIPTION
This DTC is output when the VSC system has a problem. Check the VSC system when this DTC is output.
Fig. 58: DTC P1578 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 an
y malfunctions in the communication

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

OK: Go To Next Step.
2.READ VALUE ON HAND-HELD TESTER
a. Connect the hand-held tester to the DLC3.
b. Turn the ignition switch to the ON position, and turn the hand-held tester main switch on.
c. Select the item "CCS INDICATOR M", "CCS INDICATOR S", "CCS READY M" or "CCS
READY S" in the DATA LIST, and read its value on the hand-held tester.
d. Check the CRUISE main indicator light and READY indicator light, when the cruise control main
switch is ON and when it is OFF.
CC (ECM):
DATA LIST (CC (ECM))
OK: When cruise control main switch operation is performed, the standard values will be above.
HINT:
NG: REPLACE ECM (SEE REPLACEMENT
)
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE
CIRCUIT DESCRIPTION
When the cruise control ECU (distance control ECU) detects that the wipers are operating, the dynamic radar
cruise control system will be cancelled.
HINT:
ItemMeasurement Item / Display
(Range)Normal ConditionDiagnostic
Note
CCS READY MCruise control system standby
condition (Main CPU) / ON or OFFON <=> OFF: Change ON/OFF
each time Main SW is pushed.()
CCS READY SCruise control system standby
condition (Sub CPU) / ON or OFFON <=> OFF: Change ON/OFF
each time Main SW is pushed.()
CCS
INDICATOR MCruise indicator signal (Main
CPU) /ON or OFFON: "CCS READY" ON OFF:
"CCS READY" OFF()
CCS
INDICATORSCruise indicator signal (Sub
CPU) /ON or OFFON: "CCS READY" ON OFF:
"CCS READY" OFF()
()
is OK, but
()is NG --> DTC output or ECM failure

Fig. 89: Wiring Diagram - Diagnosis Circuit
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
HINT:
When a particular warning light stays blinking, a ground short in the wiring of terminal TC of the DLC3 or an
internal ground short in the relevant ECU is suspected.
INSPECTION PROCEDURE
1.CHECK HARNESS AND CONNECTOR (TC of DLC3 - ECM)
a. Disconnect the E2 connector from the ECM.
b. Measure the resistance according to the value(s) in the table below.
Standard:
ECM CONNECTOR TERMINALS RESISTANCE
Fig. 90: Identifying DLC3 Connector (TC) Terminals

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Tester connectionConditionSpecified condition
TC (E2-3) - TC (D1 - 13)AlwaysBelow 1 ohms

BUZZERS, RELAYS & TIMERS LOCATION
CIRCUIT PROTECTION DEVICES LOCATION
ComponentLocation
ABS CUT RelayOn engine room No. 3 R/B. See Fig. 7 .
ABS MTR RelayOn engine room No. 3 R/B. See Fig. 7 .
A/C COMP RelayOn engine room No. 1 R/B. See Fig. 5 .
AIR SUS RelayOn fusible link block. See Fig. 8 .
Clearance Sonar Buzzer (Front)Behind left side of dash. See Fig. 2 .
Clearance Sonar Buzzer (Rear)Near center of rear speaker shelf, at base of rear
window. See Fig. 19
.
C/OPN RelayOn engine room No. 1 R/B. See Fig. 5 .
D-ACC RelayOn driver side J/B. See Fig. 9 .
DEFOG RelayOn engine room No. 2 R/B. See Fig. 6 .
D-IG1 RelayOn driver side J/B. See Fig. 9 .
EFI MAIN RelayOn engine room No. 1 R/B. See Fig. 5 .
FAN RelayOn fusible link block. See Fig. 8 .
F/PMP RelayOn engine room No. 1 R/B. See Fig. 5 .
Headlight Cleaner Control RelayBelow left headlight. See Fig. 1 .
HEAD LP RelayOn engine room No. 1 R/B. See Fig. 5 .
IG1 RelayOn engine room No. 1 R/B. See Fig. 5 .
IG2 RelayOn engine room No. 1 R/B. See Fig. 5 .
Keyless BuzzerInside top of left front fender, near base of "A"
pillar. See Fig. 14
.
L-ACC RelayOn luggage room J/B. See Fig. 11 .
L-IG1 RelayOn luggage room J/B. See Fig. 11 .
P-ACC RelayOn driver side J/B. See Fig. 10 .
P-IG1 RelayOn driver side J/B. See Fig. 10 .
Rear Sunshade Control RelayBelow center of rear speaker shelf. See Fig. 4 .
RR S/SHADE RelayOn luggage room J/B. See Fig. 11 .
STARTER RelayOn fusible link block. See Fig. 8 .
Telephone Transceiver & Speaker RelayOn left side of luggage compartment. See Fig. 4 .
VSC Warning BuzzerBehind lower left side of dash. See Fig. 18 .
ComponentLocation

CONTROL UNITS LOCATION
Blower Motor ResistorCenter rear of vehicle. See Fig. 29 .
Engine Room No. 1 J/BOn left front of engine compartment, behind
headlight. See Fig. 1
.
Engine Room No. 1 R/BOn left front of engine compartment, behind
headlight. See Fig. 1
.
Engine Room No. 2 R/BOn left front of engine compartment, behind
headlight. See Fig. 1
.
Engine Room No. 3 R/BOn left rear of engine compartment. See Fig. 1 .
Fuel Pump ResistorLeft rear of engine compartment. See Fig. 13 .
Fusible Link BlockOn right rear of engine compartment. See Fig. 1 .
Luggage Room J/BOn left side of luggage compartment. See Fig. 4 .
Overhead J/BAt front of roof opening. See Fig. 4 .
ComponentLocation
AFS ECURight side of dash. See Fig. 2 .
Air Suspension ECUBehind right side of dash. See Fig. 2 .
Canister Pump ModuleLeft rear of vehicle. See Fig. 19 .
Clearance Sonar ECUOn left side of luggage compartment. See Fig. 4 .
Climate Control Seat ECU (Driver's Seat)Under right side of driver's seat. See Fig. 31 .
Climate Control Seat ECU (Front Passenger's Seat)Under front passenger's seat. See Fig. 31 .
Climate Control Seat ECU (Rear LH Seat)In left side of rear seat. See Fig. 32 .
Climate Control Seat ECU (Rear RH Seat)In right side of rear seat. See Fig. 32 .
Cooling Fan ECUOn front center of engine compartment, on radiator
support. See Fig. 1
.
Distance Control ECUBehind right side of dash. See Fig. 16 .
Door Lock Control ReceiverRight rear of luggage compartment. See Fig. 19 .
Driver Door ECUInside front of left front door. See Fig. 4 .
Driver Seat ECUBelow left side of driver's seat. See Fig. 31 .
Driver Side J/B ECUAt left kick panel. See Fig. 16 .
Engine Control ModuleOn left front of engine compartment, in protective
case. See Fig. 1
.
Front ControllerOn engine room No. 2 R/B. See Fig. 6 .
Front Passenger Door ECUInside right front door. See Fig. 4 .
Gateway ECUBehind left end of dash. See Fig. 16 .
Headlight Control ECU LHBehind left headlight. See Fig. 1 .
Headlight Control ECU RHBehind right headlight. See Fig. 1 .
Luggage Room J/B ECUOn left side of luggage compartment. See Fig. 4 .
Moon Roof Control ECUAt front of roof opening. See Fig. 4 .
On lower right side of luggage compartment. See

Fuel Lid Opener MotorOn left side of luggage compartment, behind left
rear fenderwell. See Fig. 19
.
Headlight Beam Level Control Actuator LHBehind left headlight. See Fig. 13 .
Headlight Beam Level Control Actuator RHBehind right headlight. See Fig. 13 .
Headlight Cleaner MotorBelow left headlight. See Fig. 13 .
Height Control CompressorOn right front of engine compartment. See Fig. 13 .
Luggage Compartment Door Closer MotorOn center rear of luggage compartment lid. See Fig.
28 .
Power Seat Module (Rear Passenger's RH Seat Slide
Control)Right side of rear seat. See Fig. 32 .
Power Seat Motor (Driver's Seat Cushion Control)Lower left side of driver's seat. See Fig. 31 .
Power Seat Motor (Driver's Seat Front Vertical
Control)Lower left side of driver's seat. See Fig. 31 .
Power Seat Motor (Driver's Seat Lifter Control)Lower right side of driver's seat bottom. See Fig.
31 .
Power Seat Motor (Driver's Seat Lumbar Support
Lower Side Control)Lower right side of driver's seat cushion. See Fig.
31 .
Power Seat Motor (Driver's Seat Lumbar Support
Upper Side Control)Upper right side of driver's seat back. See Fig. 31 .
Power Seat Motor (Driver's Seat Reclining Control)Lower left rear side of driver's seat bottom. See Fig.
31 .
Power Seat Motor (Driver's Seat Slide Control)In lower left side of driver's seat cushion. See Fig.
31 .
Power Seat Motor (Front Passenger's Seat Front
Vertical Control)In lower right side of front passenger's seat bottom.
See Fig. 31
.
Power Seat Motor (Front Passenger's Seat Head
Rest Control)In upper left side of front passenger's seat back. See
Fig. 31
.
Power Seat Motor (Front Passenger's Seat Lifter
Control)In lower left side of front passenger's seat bottom.
See Fig. 31
.
Power Seat Motor (Front Passenger's Seat Lumbar
Support Control)Lower left rear of front passenger seat cushion. See
Fig. 31
.
Power Seat Motor (Front Passenger's Seat Reclining
Control)Lower right side of front passenger's seat. See Fig.
31 .
Power Seat Motor (Front Passenger's Seat Slide
Control)Under passenger's seat cushion. See Fig. 31 .
Power Seat Motor (Rear Passenger's LH Seat Slide
Control)Left side of rear seat. See Fig. 32 .
Power Window Motor Front LHIn left front door. See Fig. 29 .
Power Window Motor Front RHIn right front door. See Fig. 29 .
Power Window Motor Rear LHIn left rear door. See Fig. 29 .
Power Window Motor Rear RHIn right rear door. See Fig. 29 .
Rear Blower MotorCenter rear of vehicle. See Fig. 29 .
Rear Damper Servo MotorRear center of luggage compartment. See Fig. 29 .

SENDING UNITS & SENSORS LOCATION
Rear Door W/Motor Lock Assembly LHIn left rear door. See Fig. 29 .
Rear Door W/Motor Lock Assembly RHIn right rear door. See Fig. 29 .
Seat Belt Motor LHBase of left "B" pillar. See Fig. 30 .
Seat Belt Motor RHBase of right "B" pillar. See Fig. 30 .
Seat Climate Fan Motor Rear LH (Seat Back)In left rear seat back. See Fig. 32 .
Seat Climate Fan Motor Rear LH (Seat Cushion)In left rear seat cushion. See Fig. 32 .
Seat Climate Fan Motor Rear RH (Seat Back)In right rear seat back. See Fig. 32 .
Seat Climate Fan Motor Rear RH (Seat Cushion)In right rear seat cushion. See Fig. 32 .
Shoulder Belt Anchor Motor & Position Sensor
(Left)Near center of left "B" pillar. See Fig. 30 .
Shoulder Belt Anchor Motor (Right)Near center of right "B" pillar. See Fig. 30 .
StarterCenter rear of engine. See Fig. 15 .
Suspension Control Actuator Front LHOn left side of engine compartment. See Fig. 15 .
Suspension Control Actuator Front RHOn right side of engine compartment. See Fig. 15 .
Suspension Control Actuator Rear LHNear base of left "C" pillar. See Fig. 30 .
Suspension Control Actuator Rear RHNear base of right "C" pillar. See Fig. 30 .
Telescopic Motor & Position SensorInside base of steering column. See Fig. 18 .
Tilt Motor & Position SensorInside base of steering column. See Fig. 18 .
Washer MotorOn washer fluid reservoir, below left headlight. See
Fig. 15
.
Water Valve Servo MotorCenter of dash. See Fig. 18 .
ComponentLocation
ABS Speed Sensor Front LHAt left rear of engine compartment. See Fig. 12 .
ABS Speed Sensor & Pad Wear Indicator SW Front
RHRight rear of engine compartment. See Fig. 12 .
ABS Speed Sensor & Pad Wear Indicator SW Rear
RHAt right rear wheel assembly. See Fig. 19 .
ABS Speed Sensor Rear LHAt left rear wheel assembly. See Fig. 19 .
A/C Ambient Temp. SensorBehind left side of bumper fascia. See Fig. 12 .
Acceleration SensorOn left side of luggage compartment, behind left
rear fenderwell. See Fig. 19
.
Accel Position SensorBehind left center of dash. See Fig. 2 .
A/C Pressure SensorOn left front of engine compartment. See Fig. 12 .
A/C Room Temperature SensorBehind left center of dash. See Fig. 2 .
A/C Solar Sensor (Rear)Near center of rear speaker shelf, at base of rear
window. See Fig. 19
.
Airbag Sensor AssemblyFront of center console. See Fig. 2 .
Air Bag Sensor Front LHOn left front of engine compartment. See Fig. 12 .