sensor LEXUS LS430 2003 Factory Repair Manual

Fig. 74: Disconnecting ECM E3 Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE WIRE HARNESS OR CONNECTOR
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE
3.CHECK WIRE HARNESS AND CONNECTOR (LASER SENSOR - DISTANCE CONTROL
ECU)
a. Disconnect the cruise control ECU (distance control ECU) connector.
b. Measure the resistance according to the value(s) in the table below.
Standard:
LASER SENSOR AND DISTANCE CONTROL ECU TERMINALS RESISTANCE
SPECIFICATION
Tester connectionConditionSpecified value
D2-13 (IGB) - L1-5 (IGB)AlwaysBelow 1 ohms
D2-13 (IGB) - Body groundAlways10 kohms or higher

Fig. 75: Disconnecting Laser Sensor Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Fig. 76: Disconnecting Cruise Control ECU (Distance Control ECU) Connector

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE WIRE HARNESS OR CONNECTOR
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE
CIRCUIT DESCRIPTION
The cruise control main switch operates eight functions: SET, COAST, TAP-DOWN, RESUME, ACCEL,
TAP-UP, CANCEL and MODE. The SET, TAP-DOWN and COAST functions, and the RESUME, TAP-UP
and ACCEL functions are operated with the same switch. The cruise control main switch is an automatic return
type switch which turns on only while operating it in each arrow direction and turns off after releasing it. The

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

SYSTEM NAME AND PAGE REFERENCE
Keep in mind the following points when inspecting the dynamic radar cruise control system.
As there is a limitation to the vehicle-to-vehicle distance controlling capability, do not overly rely on the
dynamic radar cruise control system.
Do not neglect to pay constant attention to the vehicle-to-vehicle distance and the traffic conditions when
using the dynamic radar cruise control system. Decelerate with the brake pedal, or accelerate with the
accelerator pedal, according to the situation, to keep an appropriate distance with the vehicle in front.
When the vehicle in front decelerates rapidly or another vehicle pulls out in front of the vehicle,
decelerating in time to avoid a collision may not be possible without additional braking.
The dynamic radar cruise control system is designed to assist in maintaining an appropriate distance with
the vehicle in front. However, the system alone is not sufficient. It is imperative that the driver pays
attention at all times.
The millimeter wave radar sensor has functions to automatically detect dirt on the sensor face and inform
the driver, but it is not perfect. Keep the sensor face clean.
The dynamic radar cruise control system does not work, or give vehicle-approaching warning, for
vehicles which are stopped or driving at significantly slower speeds. Always pay attention to those other
vehicles.
The millimeter wave radar sensor detection area is narrow at close range, so detection of a vehicle pulling
out just in front may be delayed, or a motorcycle running on the side of the same lane may not be
detected. The distance to the vehicle in front may not be maintained properly due to these reasons.
Even if ACCEL is operated to increase the set vehicle speed, the vehicle does not accelerate because the
speed is controlled in accordance with the speed of the vehicle in front while driving with the vehicle-to-
vehicle distance control mode on (follow-up cruising). However, as the set vehicle speed has been
increased by ACCEL operation, the vehicle keeps accelerating when there is no vehicle in front. Check
the set speed with the set vehicle speed indication on the display.
The controlled vehicle distance may be shorter than the set vehicle distance when cruising on a long
downhill road.
Push the cruise control main switch ON-OFF button off and reset the cruise control if the master warning
light comes on, the CRUISE main indicator light blinks, and the fail indication is shown on the display
with a "pong" sound during dynamic radar cruise control operation.
The vehicle-approaching warning buzzer does not sound in the constant speed control mode because the
System NameSee Procedure
Front Power Seat Control SystemINITIALIZATION

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).

0.5 second) while the vehicle-to-vehicle distance control mode is in operation, the stored
vehicle speed decreases each time by approximately 5 km/h (CANADA) or 5 mph (USA).
h. ACCELERATOR CONTROL (Constant speed control mode)
The throttle valve motor of the throttle position sensor and motor is instructed by the ECM to
open the valve when RESUME/ACCEL on the cruise control main switch is pressed and held
while the constant speed control mode is in operation. Vehicle speed, when the cruise control
main switch is released from RESUME/ACCEL, is stored and constant speed control is
maintained.
i. ACCELERATION CONTROL (Vehicle-to-vehicle distance control mode)
When RESUME/ACCEL on the cruise control main switch is pressed and held while the
vehicle-to-vehicle distance control mode is in operation, the stored vehicle speed increases
by approximately 5 km/h (CANADA) or 5 mph (USA) per second.
Pushing the cruise control main switch to RESUME/ACCEL while following the vehicle in front
with the vehicle-to-vehicle distance control mode does not increase the actual vehicle speed, but
changes only the set vehicle speed.
j. TAP-UP CONTROL (Constant speed control mode)
When tapping up on the cruise control main switch to RESUME/ACCEL (for approximately
0.5 second) while the constant speed control mode is in operation, the stored vehicle speed
increases each time by approximately 1.6 km/h (1 mph). However, when the difference
between the driving and the stored vehicle speeds is more than 5 km/h (3 mph), the stored
vehicle speed will not be changed.
k. TAP-UP CONTROL (Vehicle-to-vehicle distance control mode)
When tapping up on the cruise control main switch to RESUME/ACCEL (for approximately
0.5 second) while the vehicle-to-vehicle distance control mode is in operation, the stored
vehicle speed increases each time by approximately 5 km/h (CANADA) or 5 mph (USA).
l. MANUAL CANCEL CONTROL
<00270052004c0051004a000300440051005c00030052004900030057004b0048000300490052004f004f0052005a004c0051004a000300460044005100460048004f005600030057004b00480003004600550058004c005600480003004600520051005700
550052004f00030056005c00560057004800500003005a004b[ile in operation. (The stored
vehicle speed in the ECM is maintained.)
Depressing the brake pedal
<003000520059004c0051004a00030057004b004800030056004b004c004900570003004f0048005900480055000300570052000300440051005c0003005300520056004c0057004c0052005100030048005b0046004800530057000300270003000b001900
57004b000f000300180057004b000f00030044005100470003[4th gears)
Pushing the cruise control main switch to CANCEL
Pushing the cruise control main switch ON-OFF button off (The stored vehicle speed
in the ECM is not maintained.)
m. RESUME CONTROL
If the cruise control operation was cancelled with the stop lamp switch or the CANCEL
switch, and if driving speed is within the limit range, pushing the cruise control main switch
to RESUME/ACCEL restores vehicle speed memorized at the time of cancellation, and
maintains constant speed control. In constant speed mode, once vehicle speed goes below the
low speed limit, RESUME operation is not possible even if accelerating up to the low speed
limit, or more, again.
5.BRAKE CONTROL

a. Check if any DTCs are output.
HINT:
The ECM and cruise control ECU (distance control ECU) of this system are connected to the CAN
communication system. Therefore, before starting troubleshooting, make sure to check that there is
no trouble in the CAN communication system.
CAN SYSTEM DTC IS OUTPUT (PROCEED TO "CAN COMMUNICATION SYSTEM
")
NO CAN SYSTEM DTC (GO TO STEP 6)
6.DTC CHECK AND CLEAR (SEE DTC CHECK/CLEAR
)
Go to Next Step.
7.DTC CHECK (OTHER THAN MULTIPLEX AND CAN SYSTEM DTC) (SEE DTC
CHECK/CLEAR )
TROUBLE CODE (GO TO STEP 8)
NORMAL SYSTEM CODE (GO TO STEP 9)
8.(SEE DIAGNOSTIC TROUBLE CODE CHART
)
GO TO STEP 12
9.PROBLEM SYMPTOM SIMULATION
SYMPTOM DOES NOT OCCUR (GO TO STEP 10)
SYMPTOM OCCURS (GO TO STEP 11)
10.SYMPTOM SIMULATION (SEE ELECTRONIC CIRCUIT INSPECTION PROCEDURE
)
Go to Next Step.
11.(SEE PROBLEM SYMPTOMS TABLE
)
Go to Next Step.
12.CIRCUIT INSPECTION (SEE DTC P0500 VEHICLE SPEED SENSOR CIRCUIT
MALFUNCTION, DTC P0503 VEHICLE SPEED SENSOR CIRCUIT MALFUNCTION -
DIAGNOSIS CIRCUIT
)
Go to Next Step.

1.DISTANCE CONTROL ECU
Fig. 20: Identifying ECU Terminals

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
ECU TERMINALS VOLTAGE AND RESISTANCE SPECIFICATION
Symbols (Terminals
No.)Wiring
ColorTerminal DescriptionConditionSpecified
Condition
+B - GND (D2-1 - D2-
12)R-B - BRBatteryAlways10 to 14V
CANH (D2 - 8)LGCAN communication
signalCAN
communication
circuit
-
CANL (D2 - 9)LCAN communication
signalCAN
communication
circuit
-
SGND - Body ground
(D2-10 - Body ground)BR - Body
groundGroundAlwaysBelow 1 ohms
GND - Body ground
(D2-12 - Body ground)BR - Body
groundGroundAlwaysBelow 1ohms
IGB - GND (D2-13 -
D2-12)L-0 - BRIgnition switch ON signalIgnition switch OFF
--> ONBelow 1 V --> 10
to 14V
LRDD - GND (D2-22 -
D2-12)P-L - BRMillimeter wave radar
sensor input signalIgnition switch ONPulse generation
(see waveform 1)
LRRD - GND (D2-23 -
D2-12)L-Y - BRMillimeter wave radar
sensor output signalIgnition switch ONPulse generation
(see waveform 2)

Fig. 24: ECM Connector Terminals Voltage And Resistance Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
If the value is not within the standard range, some defects on the vehicle are suspected.
3.MILLIMETER WAVE RADAR SENSOR

Fig. 25: Identifying Millimeter Wave Radar Sensor Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
MILLIMETER WAVE RADAR SENSOR CONNECTOR TERMINALS VOLTAGE AND
RESISTANCE SPECIFICATION
a. Reference: waveform 1
HINT:
Terminal: LRDD - SGND
Symbols (Terminal No.)Wiring
ColorTerminal DescriptionConditionSpecified Condition
LGND - Body ground
(M7-1 - Body ground)B-L -Body
groundGround (Distance signal)AlwaysBelow 1 ohms
SGND - Body ground
(M7-2 - Body ground)B-R - Body
groundGroundAlwaysBelow 1 ohms
LRDD - SGND (M7-3 -
M7-2)B-O - B-RMillimeter wave radar
sensor output signalIgnition
switch ONPulse generation (see
waveform 1)
LRRD - SGND (M7-4 -
M7-2)B-Y - B-RMillimeter wave radar
sensor input signalIgnition
switch ONPulse generation (see
waveform 2)
IGB - SGND (M7-5 - M7-
2)B - B-RPower sourceIgnition
switch ON10 to 14V