sensor LEXUS LS430 2003 Factory Repair Manual

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
1.DATA LIST
HINT:
From the DATA LIST displayed on the hand-held tester, the value of components such as the switch,
sensor, and actuator can be read without parts removal. Reading the DATA LIST as the first step of
troubleshooting is one way to shorten labor time.
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, read the "DATA LIST".
CC (ECM):
DATA LIST (CC (ECM))
Item
Measurement Item /
Display (Range)
Normal ConditionDiagnostic Note
ACCEL REQUESTAccelerator request signal /
min.: -2621.44 k/h/s, max.:
2621.36 k/h/sNo vehicle in front-
VEHICLE
DISTANCELaser sensor / min.: 0 m (0ft),
max.: 255m (836.65 ft)Distance to the vehicle in front-
L/C OPTION FLAGLaser cruise option flag / NO,
YESYES: Vehicle to vehicle distance
mode-
DISTANCE TIMECar distance time setting
condition /SHRT, MID,
LONG, NOThe vehicle selected by distance
control switch-
O/D CUT RQSTO/D cut request / NOT REQ,
REQUESTNOT REQ: Idling-
3RD SHIFT DOWNShift down request to 3rd
gear / NOT REQ, REQUESTNOT REQ: Idling-
4TH SHIFT DOWNShift down request to 4th
gear / NOT REQ, REQUESTNOT REQ: Idling-
ALARM RQSTAlarm request signal / NOT
REQ, REQUESTREQUEST: When beeping NOT
REQ: When not beeping-
THROTTLE CLOSEAll throttle close request /
NOT REQ, REQUESTON: REQUEST OFF: NOT
REQUEST-
BRAKE CTRL RQSTBrake control request / NOT
REQ, REQUESTON: REQUEST OFF: NOT
REQUEST-
TARG DECL SLOPECruise target deceleration
slope / 0.03, 0.06, 0.11, 0.160.03, 0.06, 0.11, 0.16-

VEHICLE SPDVehicle speed sensor/min.: 0
km/h (0 mph), max.: 255
km/h (158 mph)Actual vehicle speed-
MEMORY SPDCruise control memorized
speed / min.: 0 km/h (0 mph),
max.: 255 km/h (158 mph)Memorized speed: Cruise control
activated-
THROTTLERequired throttle opening
angle / min.: 0 deg, max.: 125
degRequired throttle opening angle:
Cruise control activated-
RQST TORQUECruise request torque/min.: -
1024 Nm, max.: 1016 Nm--
CRUISE CTRLCruise control system active
condition / ON or OFFON: Cruise control activated
OFF: Cruise control inactivated-
MAIN SW (MAIN)Main SW signal (Main
CPU) / ON or OFFON: Main SW ON (Pushed on)
OFF: Main SW OFF (Pushed
off)*3
MAIN SW (SUB)Main SW signal (Sub CPU) /
ON or OFFON: Main SW ON (Pushed on)
OFF: Main SW OFF (Pushed
off)*3
CCS READY MCruise control system
standby condition (Main
CPU) / ON or OFFON <=> OFF: Change ON/OFF
each time Main SW is pushed.*1
ItemMeasurement Item / Display
(Range)Normal ConditionDiagnostic Note
CCS READY SCruise control system
standby condition (Sub
CPU) / ON or OFFON <=> OFF: Change ON/OFF
each time Main SW is pushed.*1
CCS INDICATOR MCruise indicator signal (Main
CPU) / ON or OFFON: "CCS READY" ON OFF:
"CCS READY" OFF*2
CCS INDICATOR SCruise indicator signal (Sub
CPU) / ON or OFFON: "CCS READY" ON OFF:
"CCS READY" OFF*2
CANCEL SWCANCEL SW signal / ON or
OFFON: CANCEL SW ON OFF:
CANCEL SW OFF-
SET/COAST SWSET/COAST SW signal / ON
or OFFON: SET/COAST SW ON OFF:
SET/COAST SW OFF-
RES/ACC SWRES/ACC SW signal / ON or
OFFON: RES/ACC SW ON OFF:
RES/ACC OFF-
STP LIGHT SW MStop lamp SW signal (Main
CPU) / ON or OFFON: Brake pedal depressed OFF:
Brake pedal released-
STP LIGHT SW S1Stop lamp SW signal (Sub
CPU) / ON or OFFON: Brake pedal depressed OFF:
Brake pedal released-
STP LIGHT SW S2Stop lamp SW signal (Sub
CPU) / ON or OFFON: Brake pedal depressed OFF:
Brake pedal released-
SHIFT D POSPNP SW signal (D position) /
ON or OFFON: Shift D position OFF:
Except shift D position-

HINT:
If a trouble code is displayed during the DTC check, check the circuit listed for that code. For details of each
code, refer to the DTC chart below.
DIAGNOSTIC TROUBLE CODE CHART
L-CRUISE DISPGraphic area is ON / OFF((1))
L-CRS CHECK IND"CHECK CRUISE SYSTEM" indicator is ON / OFF-
L-CRS READY IND"RADAR READY" indicator is ON / OFF-
(1)The entire graphic area in the combination meter will light up.
DTCDescription
DTC P0500, DTC
P0503
VEHICLE SPEED SENSOR CIRCUIT MALFUNCTION
DTC P0571STOP LIGHT SWITCH CIRCUIT MALFUNCTION
DTC P0607INPUT SIGNAL CIRCUIT MALFUNCTION
DTC P1615, DTC
U1101
COMMUNICATION ERROR FROM DISTANCE CONTROL ECU TO
ECM
DTC P1616, DTC
U0100
COMMUNICATION ERROR FROM ECM TO DISTANCE CONTROL
ECU
DTC P1617DISTANCE CONTROL ECU MALFUNCTION
DTC P1630, DTC
U0122
COMMUNICATION ERROR FROM VSC TO ECM
DTC P1631, DTC
U0100
COMMUNICATION ERROR FROM ECM TO VSC
DTC P1575WARNING BUZZER MALFUNCTION
DTC P1578BRAKE SYSTEM MALFUNCTION
DTC U0235LOST COMMUNICATION WITH CRUISE CONTROL FRONT
DISTANCE RANGE SENSOR
DTC U1102LOST COMMUNICATION WITH RADAR SENSOR
DTC P1570RADAR SENSOR MALFUNCTION
DTC P1572IMPROPER AIMING OF RADAR SENSOR BEAM AXIS
DTC U0126LOST COMMUNICATION WITH STEERING ANGLE SENSOR MODULE
DTC U0123LOST COMMUNICATION WITH YAW RATE SENSOR MODULE

OK: REPLACE DRIVER SIDE J/B
CIRCUIT DESCRIPTION
This DTC indicates a malfunction in the ECM.
HINT:
The ECM receives signals from each sensor to control all the functions of the cruise control with the
microcomputer.
When a malfunction is detected, fail-safe remains on until the ignition switch is turned off.
DTC P0607 PROBLEM SYMPTOM DIAGNOSTIC
INSPECTION PROCEDURE
1.REPLACE ECM (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
The distance control ECU receives information about the area in front of the vehicle from the laser sensor and
then sends a brake control demand signal (deceleration demand) and diagnosis signals, such as laser sensor
grime or laser sensor malfunction, to the ECM.
DTC No.Detection ItemTrouble Area
P0607The ECM has a supervisory CPU and a control ECU inside. When each
input STP signal is different for 0.15 sec. or more, this trouble code is
output. This trouble code is output after 0.4 sec. has passed from the time
the cruise cancel input signal (STP input) is input into the ECM.ECM

Fig. 50: DTC P1615 And U1101 Problem Symptom Diagnostic Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
HINT:
This circuit uses CAN for communication. Therefore, one or more DTCs in the CAN communication system
is/are output if there are any malfunctions in the communication circuit.
1.GO TO CAN COMMUNICATION SYSTEM (SEE HOW TO PROCEED WITH
TROUBLESHOOTING )
CIRCUIT DESCRIPTION
The ECM receives signals from each sensor and ECU, then sends signals such as the A/T signal, cruise control
<005200530048005500440057004c0052005100030056004c004a00510044004f000f0003004f0052005a0003005600530048004800470003005200530048005500440057004c0052005100030056004c004a00510044004f000f0003004500550044004e00
480003004600520051005700550052004f0003005200530048[ration signal and laser light emission prohibiting
signal, etc. to the distance control ECU.
<0037004b004800030028002600300003004c005600030057004b0048000300520051004f005c000300460052005000530052005100480051005700030057004b004400570003004b0044005600030044000300490058005100460057004c00520051000300
57005200030055004800460052005500470003004400510047[ output the DTCs in the dynamic laser cruise
control system. Therefore if the distance control ECU detects a communication error from the ECM, it sends the
malfunction signal back to the ECM.
Fig. 51: DTC P1616 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.

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.
DTC P1578 PROBLEM SYMPTOM DIAGNOSTIC
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.CHECK BRAKE SYSTEM (SEE HOW TO PROCEED WITH TROUBLESHOOTING
)
CIRCUIT DESCRIPTION
The laser sensor and cruise control ECU (distance control ECU) transmit the data for general vehicle control
and diagnosis function along the communication line.
The laser sensor transmits information about the vehicle in front to the cruise control ECU (distance control
ECU).
DTC No.DTC Detection ConditionTrouble Area
P1578This trouble code is output when the ECM receives the brake
system error signal for 0.2 sec. or more while the dynamic laser
cruise control is in operation.VSC system

Fig. 55: DTC U0235 Problem Symptom Diagnostic Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
WIRING DIAGRAM
Fig. 56: Wiring Diagram
- Lost Communication With Cruise Control Front Distance Range Sensor
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.CHECK WIRE HARNESS AND CONNECTOR (DISTANCE CONTROL ECU - LASER
SENSOR)
a. Disconnect the distance control ECU and laser sensor connectors.
b. Measure the resistance according to the value(s) in the table below.
Standard:
DISTANCE CONTROL ECU AND LASER SENSOR CONNECTOR TERMINALS
RESISTANCE SPECIFICATION
Tester connectionConditionSpecified value
D2-22 (LRDD) - L1-3 (LRDD)AlwaysBelow 1 ohms
D2-13 (IGB) - L1-5 (IGB)AlwaysBelow 1 ohms
D2-22 (LRDD) - Body groundAlways10 kohms or higher
D2-13 (IGB) - Body groundAlways10 kohms or higher

Fig. 58: Disconnecting Laser Sensor Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: Go To Next Step.
2.INSPECT LASER SENSOR
a. Reconnect the laser sensor connector.
b. Measure the voltage according to the value(s) in the table below.
Standard:
LASER SENSOR TERMINALS VOLTAGE SPECIFICATION
Tester connectionConditionSpecified value
L1-5 (IGB) - Body groundIgnition SW ON10 to 14 V

Fig. 59: Identifying Laser Sensor Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
c. Check the signal waveform between terminal LRDD (L1-3) of the laser sensor and body ground.
OK:
A waveform similar to that in the illustration to the left is output.
HINT:
Gauge set: 1 V/DIV, 2 ms/DIV
Condition: Ignition switch ON
NG: REPLACE LASER SENSOR (SEE REPLACEMENT
)

Fig. 60: Signal Waveform Graph
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: REPLACE CRUISE CONTROL ECU ASSY (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
The laser sensor and cruise control ECU (distance control ECU) transmit the data for general vehicle control
and diagnosis function along the communication line.
The cruise control ECU (distance control ECU) determines the presumed R information based on the signal
from the steering wheel and yaw rate sensor.
The cruise control ECU (distance control ECU) transmits the current vehicle speed and presumed R information
to the laser sensor.