2003 LEXUS LS430 sensor

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.
Fig. 52: DTC P0607 Problem Symptom Diagnostic Chart

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
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 millimeter wave
radar sensor and then sends a brake control demand signal (deceleration demand) and diagnosis signals, such as
millimeter wave radar sensor grime or millimeter wave radar sensor malfunction, to the ECM.

Fig. 53: 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 PRECAUTION
)
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 radar 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. 54: DTC P1616 And U0100 Problem Symptom Diagnostic Chart

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

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 Millimeter wave radar sensor and cruise control ECU (distance control ECU) transmit the data for general
vehicle control and diagnosis function along the communication line.
The Millimeter wave radar sensor transmits information about the vehicle in front to the cruise control ECU
(distance control ECU).
Fig. 59: DTC U0235 Problem Symptom Diagnostic Chart

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
WIRING DIAGRAM
Fig. 60: 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 - MILLIMETER

WAVE RADAR SENSOR)
a. Disconnect the distance control ECU and millimeter wave radar sensor connectors.
b. Measure the resistance according to the value(s) in the table below.
Standard:
DISTANCE CONTROL ECU AND MILLIMETER WAVE RADAR SENSOR TERMINALS
RESISTANCE SPECIFICATION
Fig. 61: Disconnecting Distance Control ECU Connector

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Tester connectionConditionSpecified value
D2-22 (LRDD) - M7-3 (LRDD)AlwaysBelow 1 ohms
D2-13 (IGB) - M7-5 (IGB)AlwaysBelow 1 ohms
D2-22 (LRDD) - Body groundAlways10 kohms or higher
D2-13 (IGB) - Body groundAlways10 kohms or higher

Fig. 62: 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 MILLIMETER WAVE RADAR SENSOR ASSY
a. Reconnect 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

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. 64: Signal Waveform Graph
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: REPLACE CRUISE CONTROL ECU ASSY (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
The millimeter wave radar 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 millimeter wave radar sensor.

Fig. 65: DTC U1102 Problem Symptom Diagnostic Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
WIRING DIAGRAM
Fig. 66: Wiring Diagram
- Lost Communication With Radar Sensor
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.CHECK WIRE HARNESS AND CONNECTOR (DISTANCE CONTROL ECU - MILLIMETER
WAVE RADAR SENSOR)
a. Disconnect the distance control ECU and millimeter wave radar sensor connectors.
b. Measure the resistance according to the value(s) in the table below.
Standard:
DISTANCE CONTROL ECU AND MILLIMETER WAVE RADAR SENSOR TERMINALS
RESISTANCE SPECIFICATION
Tester connectionConditionSpecified value
D2-23 (LRRD) - M7-4 (LRRD)AlwaysBelow 1 ohms
D2-13 (IGB) - M7-5 (IGB)AlwaysBelow 1 ohms
D2-23 (LRRD) - Body groundAlways10 kohms or higher
D2-13 (IGB) - Body groundAlways10 kohms or higher