LEXUS LS430 2003 Factory Repair Manual

Fig. 41: Identifying Ultrasonic Sensor No.1 Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: Go To Next Step.
2.CHECK HARNESS AND CONNECTOR (CLEARANCE WARNING ECU ASSY -
ULTRASONIC SENSOR NO. 1)
a. Disconnect the C17 connector from the clearance warning ECU assy.
b. Disconnect the U6 connector from ultrasonic sensor No.1.
c. Measure the resistance according to the value (s) in the table below.
TESTER CONNECTION SPECIFIED CONDITION
Tester connection (Symbols)ConditionSpecified value
C17-9 (FRS) - U6-2AlwaysBelow 1 ohms
C17-8 (FGND) - U6-1AlwaysBelow 1 ohms
C17-9 (FRS) - Body groundAlways10 kohms or higher
C17-8 (FGND) - Body groundAlways10 kohms or higher

Fig. 42: Identifying Clearance Warning ECU Assy Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: REPLACE CLEARANCE WARNING ECU ASSY (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
Ultrasonic sensor consists of a sensor portion that transmits and receives ultrasonic waves and a pre-amplifier
that amplifies them. The ultrasonic sensor outputs the ultrasonic transmission and reception signals to the
clearance warning ECU assy.
Fig. 43: DTC B2237 Detection Condition And Trouble Area Description Chart

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

Fig. 44: Rear Left Sensor Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.INSPECT ULTRASONIC SENSOR NO.1
a. Remove ultrasonic sensor No.1.
b. Measure the resistance according to the value (s) in the table below.
TESTER CONNECTION SPECIFIED CONDITION
NG: REPLACE ULTRASONIC SENSOR NO.1 (SEE REPLACEMENT
)
Tester connectionConditionSpecified condition
1-2Always10 +/- 2 kohms

Fig. 45: Identifying Ultrasonic Sensor No.1 Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: Go To Next Step.
2.CHECK HARNESS AND CONNECTOR (CLEARANCE WARNING ECU ASSY -
ULTRASONIC SENSOR NO. 1)
a. Disconnect the C17 connector from the clearance warning ECU assy.
b. Disconnect the U9 connector from ultrasonic sensor No.1.
c. Measure the resistance according to the value (s) in the table below.
TESTER CONNECTION SPECIFIED CONDITION
Tester connection (Symbols)ConditionSpecified value
C17-25 (RL) - U9-2AlwaysBelow 1 ohms
C17-20 (RGND) - U9-1AlwaysBelow 1 ohms
C17-25 (RL) - Body groundAlways10 kohms or higher
C17-20 (RGND) - Body groundAlways10 kohms or higher

Fig. 46: Identifying Clearance Warning ECU Assy Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: REPLACE CLEARANCE WARNING ECU ASSY (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
Ultrasonic sensor consists of a sensor portion that transmits and receives ultrasonic waves and a pre-amplifier
that amplifies them. The ultrasonic sensor outputs the ultrasonic transmission and reception signals to the
clearance warning ECU assy.
Fig. 47: DTC B2238 Detection Condition And Trouble Area Description Chart

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

Fig. 48: Rear Left Center Sensor Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.INSPECT ULTRASONIC SENSOR NO.2
a. Remove ultrasonic sensor No.2.
b. Measure the resistance according to the value (s) in the table below.
TESTER CONNECTION SPECIFIED CONDITION
Fig. 49: Identifying Ultrasonic Sensor No.2 Terminals

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Tester connectionConditionSpecified condition
1 - 2Always10 +/- 2 kohms

NG: REPLACE ULTRASONIC SENSOR NO.2 (SEE REPLACEMENT )
OK: Go To Next Step.
2.CHECK HARNESS AND CONNECTOR (CLEARANCE WARNING ECU ASSY -
ULTRASONIC SENSOR NO. 2)
a. Disconnect the C17 connector from the clearance warning ECU assy.
b. Disconnect the U8 connector from ultrasonic sensor No.2.
c. Measure the resistance according to the value (s) in the table below.
TESTER CONNECTION SPECIFIED CONDITION
Tester connection (Symbols)ConditionSpecified value
C17-24 (RBL) - U8-2AlwaysBelow 1 ohms
C17-20 (RGND) - U8-1AlwaysBelow 1 ohms
C17-24 (RBL) - Body groundAlways10 kohms or higher
C17-20 (RGND) - Body groundAlways10 kohms or higher