2003 LEXUS LS430 ignition

c. Check the signal waveform between terminal LRDD (M7-3) of the millimeter wave radar 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 MILLIMETER WAVE RADAR SENSOR ASSY (SEE ADJUSTMENT
)
Fig. 63: Reconnecting Millimeter Wave Radar Sensor Connector

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Tester connectionConditionSpecified value
M7-5 (IGB) - Body groundIgnition SW ON10 to 14V

Fig. 68: Disconnecting Millimeter Wave Radar Sensor Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE WIRE HARNESS OR CONNECTOR
OK: Go To Next Step.
2.INSPECT CRUISE CONTROL ECU ASSY (DISTANCE CONTROL ECU)
a. Reconnect the cruise control ECU (distance control ECU) connector.
b. Turn the ignition switch to the ON position.
c. Measure the voltage according to the value(s) in the table below.
Standard:

CRUISE CONTROL ECU TERMINALS VOLTAGE SPECIFICATION
d. Check the signal waveform between terminal LRRD (D2-23) of the cruise control ECU (distance
control ECU) and body ground.
OK:
A waveform similar to that in the illustration to the left is output.
HINT:
Gauge set: 2 V/DIV, 5 ms/DIV
Condition: Ignition switch ON
NG: REPLACE CRUISE CONTROL ECU ASSY (SEE REPLACEMENT
)
Fig. 69: Reconnecting Cruise Control ECU (Distance Control ECU) Connector

Tester connectionConditionSpecified value
D2-13 (IGB) - Body groundIgnition SW ON10 to 14V

c. Measure the resistance according to the value(s) in the table below.
Standard:
CRUISE CONTROL ECU TERMINALS RESISTANCE SPECIFICATION
NG: REPAIR OR REPLACE WIRE HARNESS OR CONNECTOR
Fig. 75: Disconnecting Cruise Control ECU (Distance Control ECU) Connector

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE
Tester connectionConditionSpecified value
D2-1 (+B) - Body groundIgnition SW ON10 to 14V
Tester connectionConditionSpecified Value
D2-10 (SGND) - Body groundAlwaysBelow 1 ohms
D2-12 (GND) - Body groundAlwaysBelow 1 ohms

Fig. 76: Wiring Diagram - Sensor Power Source Circuit
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.INSPECT MILLIMETER WAVE RADAR SENSOR ASSY
a. Disconnect the millimeter wave radar sensor connector.
b. Measure the voltage according to the value(s) in the table below.
Standard:
MILLIMETER WAVE RADAR SENSOR TERMINALS VOLTAGE SPECIFICATION
NG: Go to step
Tester connectionConditionSpecified value
M7-5 (IGB) - Body groundIgnition SW ON10 to 14V

The dynamic laser 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.
The operation of the constant speed control mode is the same as that for the conventional type cruise
control system.
WIRING DIAGRAM
Fig. 82: Wiring Diagram
- Cruise Control Switch Circuit
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.READ VALUE OF HAND-HELD TESTER
a. Connect the hand-held tester to the DLC3.
b. Turn the ignition switch to the ON position.
c. Accordin
g to the display on the tester, read the "DATA LIST".

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: REPLACE ECM (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
The distance control switch sets the vehicle-to-vehicle distance mode.
The distance control switch (DISP2 button) is installed in the steering pad switch modulator. The vehicle-to-
vehicle distance set value can be changed by operating the distance control switch (DISP2 button) while the
dynamic radar cruise control system is in operation.
The steering pad switch modulator uses BEAN to communicate with each ECU. Therefore it does not have a
direct connection with the ECM. If there are any malfunctions in the communication line of the steering pad
switch modulator, one or more DTCs in the multiplex communication system is/are output.
INSPECTION PROCEDURE
1.READ VALUE ON HAND-HELD TESTER
a. Connect the hand-held tester to the DLC3.
b. Turn the ignition switch to the ON position.
c. Select the item "DISP2 (MULTI MODE SW)" in the DATA LIST, and read its value on the hand-
held tester.
d. Check the indication displayed on the hand-held tester, when the steering pad switch (DISP2) is
ON and when it is OFF.
MULTI-INFORMATION DISPLAY CONTROL SWITCH (STEERING PAD SWITCH
MODULATOR):
DATA LIST (MULTI-INFORMATION DISPLAY CONTROL SWITCH (STEERING PAD
SWITCH MODULATOR))
OK: When switch operation is performed the standard values will be above.
NG: REPLACE STEERING PAD SWITCH MODULATOR
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE
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.-

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