LEXUS LS430 2003 Factory Repair Manual

malfunctions in this circuit, check for DTCs in the CAN communication and multiplex communication systems.
When the wiper is in the LO or HI mode, the dynamic laser cruise control is automatically cancelled and goes
into the standby mode. (In INT (intermittent operation) mode, the laser cruise control is not cancelled.)
INSPECTION PROCEDURE
1.INSPECT WIPER AND WASHER SYSTEM (SEE INSPECTION
)
OK:
Wiper function is normal.
NG: GO TO WIPER AND WASHER SYSTEM (SEE HOW TO PROCEED WITH
TROUBLESHOOTING )
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN DIAGNOSTIC TROUBLE
CODE CHART
CIRCUIT DESCRIPTION
This circuit outputs trouble codes on the multi-information display in the combination meter when terminals TC
and CG of the DLC3 are connected.
WIRING DIAGRAM
Fig. 84: Wiring Diagram
- Diagnosis Circuit

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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 SPECIFICATION
Fig. 85: Identifying DLC3 Connector (TC) Terminals

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Tester connectionConditionSpecified condition
TC (E2-3) - TC (D1 - 13)AlwaysBelow 1 ohms

Fig. 86: Disconnecting E2 Connector From ECM
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NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (DLC3 - ECM)
OK: Go To Next Step.
2.CHECK HARNESS AND CONNECTOR (CG of DLC3 - BODY GROUND)
a. Measure the resistance according to the value(s) in the table below.
Standard:
ECM CONNECTOR TERMINALS RESISTANCE SPECIFICATION
Fig. 87: Identifying DLC3 Connector (CG) Terminals

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NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (DLC3 - BODY GROUND)
Tester connectionConditionSpecified condition
CG (D1-4) - Body groundAlwaysBelow 1 ohms

OK: Go To Next Step.
3.CHECK HARNESS AND CONNECTOR (TC of DLC3 - BODY GROUND)
a. Measure the resistance according to the value(s) in the table below.
Standard:
ECM CONNECTOR TERMINALS RESISTANCE SPECIFICATION
Fig. 88: Identifying DLC3 Connector (TC) Terminals

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NG: REPAIR OR REPLACE WIRE HARNESS AND EACH ECU
OK: REPLACE ECM (SEE REPLACEMENT
)
Tester connectionConditionSpecified condition
TC (D1-13) - Body groundAlways10 kohms or higher

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

existence of the vehicle in front and the distance to it are not judged as in the vehicle-to-vehicle distance
control mode. Pay attention to the distance to the vehicle in front.
The dynamic radar cruise control system has two cruise control modes: the constant speed control mode
and vehicle-to-vehicle distance control mode. Confirm which mode is selected when using the dynamic
radar cruise control system.

Fig. 1: Identifying Dynamic Radar Cruise Control System Electrical Components Location (1 Of 2)
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Fig. 2: Identifying Dynamic Radar Cruise Control System Electrical Components Location (2 Of 2)

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Fig. 3: Wiring Diagram - Dynamic Radar Cruise Control System
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Input and output signals of each ECU.
Fig. 4: ECU Input And Output Signals Chart (1 Of 2)

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