Lexus RX (RX 350L, RX450h) 2016-2024 Repair Manual: Lost Communication with Blind Spot Monitor Slave Module (U0232,U0233)

Lexus RX (RX 350L, RX450h) 2016-2024 Repair Manual / Audio & Visual & Telematics / Park Assist / Monitoring / Intelligent Clearance Sonar System / Lost Communication with Blind Spot Monitor Slave Module (U0232,U0233)

DESCRIPTION

This DTC is stored when the blind spot monitor sensor LH judges that there is a communication problem with the blind spot monitor sensor RH.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
U0232	Lost Communication with Blind Spot Monitor Slave Module	The clearance warning ECU assembly cannot receive signals from the blind spot monitor sensor (slave)	Open or short in CAN bus main wire or connector Open or short in CAN bus wire or connector Open or short in No. 6 CAN junction connector Clearance warning ECU assembly Blind spot monitor sensor RH Power source circuit of blind spot monitor sensor RH Blind spot monitor sensor RH ground circuit Blind spot monitor sensor LH
U0233	Lost Communication with Blind Spot Monitor Master Module	The clearance warning ECU assembly cannot receive signals from the blind spot monitor sensor (master)	Open or short in CAN bus main wire or connector Open or short in CAN bus wire or connector Open or short in No. 6 CAN junction connector Clearance warning ECU assembly Blind spot monitor sensor LH Power source circuit of blind spot monitor sensor LH Blind spot monitor sensor LH ground circuit Blind spot monitor sensor RH

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Inspect the fuses for circuits related to this system before performing the following procedure.
Before measuring the resistance of the CAN bus, turn the engine switch off and leave the vehicle for 1 minute or more without operating the key or any switches, or opening or closing the doors. After that, disconnect the cable from the negative (-) battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.
After turning the engine switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.
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HINT:

Operating the engine switch, any other switches or a door triggers related ECU and sensor communication on the CAN. This communication will cause the resistance value to change.
Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below may help determine the cause of the malfunction.

PROCEDURE

CHECK DTC

(a) Check for DTCs.

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Body Electrical > Advanced Parking Guidance/ICS/Intuitive P/A > Trouble Codes

Result	Proceed to
DTC U0232 is only output	A
DTC U0233 is only output	B
DTC U0232 and U0233 are output	C

GO TO STEP 5

GO TO STEP 8

2.	CHECK CAN BUS MAIN WIRE

(a) Disconnect the cable from the negative (-) battery terminal.

(b) Disconnect the W2 blind spot monitor sensor RH connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
W2-1 (CA2P) -W2-6 (CA2N)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω

*a	Front view of wire harness connector (to Blind Spot Monitor Sensor RH)

REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (BLIND SPOT MONITOR SENSOR RH - NO. 6 CAN JUNCTION CONNECTOR)

3.	CHECK HARNESS AND CONNECTOR (BLIND SPOT MONITOR SENSOR RH - BODY GROUND)

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REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (BLIND SPOT MONITOR SENSOR RH - NO. 6 CAN JUNCTION CONNECTOR)

4.	CHECK HARNESS AND CONNECTOR (BLIND SPOT MONITOR SENSOR RH POWER SOURCE)

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REPLACE BLIND SPOT MONITOR SENSOR RH

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.	CHECK CAN BUS MAIN WIRE

(a) Disconnect the cable from the negative (-) battery terminal.

(b) Disconnect the X2 blind spot monitor sensor LH connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
X2-1 (CA2P) -X2-6 (CA2N)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω

*a	Front view of wire harness connector (to Blind Spot Monitor Sensor LH)

REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (BLIND SPOT MONITOR SENSOR LH - NO. 6 CAN JUNCTION CONNECTOR)

6.	CHECK HARNESS AND CONNECTOR (BLIND SPOT MONITOR SENSOR LH - BODY GROUND)

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REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (BLIND SPOT MONITOR SENSOR RH - NO. 6 CAN JUNCTION CONNECTOR)

7.	CHECK HARNESS AND CONNECTOR (BLIND SPOT MONITOR SENSOR LH POWER SOURCE)

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REPLACE BLIND SPOT MONITOR SENSOR LH

REPAIR OR REPLACE HARNESS OR CONNECTOR

8.	CHECK CAN BUS MAIN WIRE (BLIND SPOT MONITOR SENSOR RH)

(a) Turn the engine switch off.

(b) Disconnect the cable from the negative (-) battery terminal.

Standard Resistance:

Tester Connection	Condition	Specified Condition	Result
J98-1 (CANH) -J98-12 (CANL)	Cable disconnected from negative (-) battery terminal	54 to 69 Ω	Below 54 Ω: Short circuit between bus lines
J98-1 (CANH) -J98-12 (CANL)	Cable disconnected from negative (-) battery terminal	54 to 69 Ω	70 Ω or more: Open circuit in main bus lines
J98-1 (CANH) - J141-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher	Below 200 Ω: CANH short to ground
J98-12 (CANL) - J141-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher	Below 200 Ω: CANL short to ground
J98-1 (CANH) - J141-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher	Below 6 kΩ: CANH +B short
J98-12 (CANL) - J141-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher	Below 6 kΩ: CANL +B short

DLC3

Component with harness connected

(No. 6 CAN Junction Connector)

Result	Proceed to
OK	A
Open circuit in CAN main bus lines	B
Short circuit between bus lines	C
Short to ground +B short	D

GO TO STEP 11

GO TO STEP 15

GO TO STEP 19

9.	CONFIRM CAN BUS WIRE (CLEARANCE WARNING ECU ASSEMBLY)

(a) Disconnect the J38 clearance warning ECU assembly connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
J38-37 (CANH) - J38-38 (CANL)	Cable disconnected from negative (-) battery terminal	54 to 69 Ω

*a	Front view of wire harness connector (to Clearance Warning ECU Assembly)

REPAIR OR REPLACE CAN BUS WIRE (CLEARANCE WARNING ECU ASSEMBLY - NO. 6 CAN JUNCTION CONNECTOR)

10.

CHECK DTC

(a) Clear the DTCs.

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Body Electrical > Advanced Parking Guidance/ICS/Intuitive P/A > Clear DTCs

(b) Check for DTCs.

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Body Electrical > Advanced Parking Guidance/ICS/Intuitive P/A > Trouble Codes

Result	Proceed to
DTC U0232 and U0233 are output	A
DTC U0232 and U0233 are not output	B

REPLACE CLEARANCE WARNING ECU ASSEMBLY

USE SIMULATION METHOD TO CHECK

11.	CHECK FOR OPEN IN CAN BUS WIRE (NO. 6 CAN JUNCTION CONNECTOR)

(a) Disconnect the J98 No. 6 CAN junction connector.

*a	Front view of wire harness connector (to No. 6 CAN Junction Connector)
*b	to blind spot monitor sensor LH CAN main wire
*c	to blind spot monitor sensor RH CAN main wire
*d	to clearance warning ECU assembly CAN wire

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
J98-3 (CANH) - J98-14 (CANL)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω
J98-1 (CANH) - J98-12 (CANL)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω
J98-2 (CANH) - J98-13 (CANL)	Cable disconnected from negative (-) battery terminal	200 Ω or higher

Result	Proceed to
OK	A
NG (to blind spot monitor sensor LH CAN main wire)	B
NG (to blind spot monitor sensor RH CAN main wire)	C
NG (to clearance warning ECU assembly CAN wire)	D

REPLACE NO. 6 CAN JUNCTION CONNECTOR

GO TO STEP 13

GO TO STEP 14

12.	CHECK FOR OPEN IN CAN BUS MAIN WIRE (BLIND SPOT MONITOR SENSOR LH)

(a) Reconnect the J98 No. 6 CAN junction connector.

(b) Disconnect the X2 blind spot monitor sensor LH connector.

*a	Front view of wire harness connector (to Blind Spot Monitor Sensor LH)

Standard Resistance:

Tester Connection	Condition	Specified Condition
X2-1 (CA2P) - X2-6 (CA2N)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω

REPLACE BLIND SPOT MONITOR SENSOR LH

REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (BLIND SPOT MONITOR SENSOR LH - NO. 6 CAN JUNCTION CONNECTOR)

13.	CHECK FOR OPEN IN CAN BUS MAIN WIRE (BLIND SPOT MONITOR SENSOR RH)

(a) Reconnect the J98 No. 6 CAN junction connector.

(b) Disconnect the W2 blind spot monitor sensor RH connector.

*a	Front view of wire harness connector (to Blind Spot Monitor Sensor RH)

Standard Resistance:

Tester Connection	Condition	Specified Condition
W2-1 (CA2P) -W2-6 (CA2N)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω

REPLACE BLIND SPOT MONITOR SENSOR RH

REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (BLIND SPOT MONITOR SENSOR RH - NO. 6 CAN JUNCTION CONNECTOR)

14.	CHECK FOR OPEN IN CAN BUS WIRE (CLEARANCE WARNING ECU ASSEMBLY)

(a) Reconnect the J98 No. 6 CAN junction connector.

(b) Disconnect the J38 clearance warning ECU connector.

*a	Front view of wire harness connector (to Clearance Warning ECU Assembly)

Standard Resistance:

Tester Connection	Condition	Specified Condition
J38-37 (CANH) - J38-38 (CANL)	Cable disconnected from negative (-) battery terminal	54 to 69 Ω

REPLACE CLEARANCE WARNING ECU ASSEMBLY

REPAIR OR REPLACE CAN BUS WIRE (CLEARANCE WARNING ECU ASSEMBLY - NO. 6 CAN JUNCTION CONNECTOR)

15.	CHECK FOR SHORT IN CAN BUS WIRES (NO. 6 CAN JUNCTION CONNECTOR)

(a) Disconnect the J98 No. 6 CAN junction connector.

*a	Front view of wire harness connector (to No. 6 CAN Junction Connector)
*b	to blind spot monitor sensor LH CAN main wire
*c	to blind spot monitor sensor RH CAN main wire
*d	to clearance warning ECU assembly CAN wire

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
J98-3 (CANH) - J98-14 (CANL)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω
J98-1 (CANH) - J98-12 (CANL)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω
J98-2 (CANH) - J98-13 (CANL)	Cable disconnected from negative (-) battery terminal	200 Ω or higher

Result	Proceed to
OK	A
NG (to blind spot monitor sensor LH CAN main wire)	B
NG (to blind spot monitor sensor RH CAN main wire)	C
NG (to clearance warning ECU assembly CAN wire)	D

REPLACE NO. 6 CAN JUNCTION CONNECTOR

GO TO STEP 17

GO TO STEP 18

16.	CHECK FOR SHORT IN CAN BUS WIRES (BLIND SPOT MONITOR SENSOR LH)

(a) Reconnect the J98 No. 6 CAN junction connector.

(b) Disconnect the X2 blind spot monitor sensor LH connector.

*a	Front view of wire harness connector (to Blind Spot Monitor Sensor LH)

Standard Resistance:

Tester Connection	Condition	Specified Condition
X2-1 (CA2P) - X2-6 (CA2N)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω

REPLACE BLIND SPOT MONITOR SENSOR LH

REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (BLIND SPOT MONITOR SENSOR LH - NO. 6 CAN JUNCTION CONNECTOR)

17.	CHECK FOR SHORT IN CAN BUS WIRES (BLIND SPOT MONITOR SENSOR RH)

(a) Reconnect the J98 No. 6 CAN junction connector.

(b) Disconnect the W2 blind spot monitor sensor RH connector.

*a	Front view of wire harness connector (to Blind Spot Monitor Sensor RH)

Standard Resistance:

Tester Connection	Condition	Specified Condition
W2-1 (CA2P) -W2-6 (CA2N)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω

REPLACE BLIND SPOT MONITOR SENSOR RH

REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (BLIND SPOT MONITOR SENSOR RH - NO. 6 CAN JUNCTION CONNECTOR)

18.	CHECK FOR SHORT IN CAN BUS WIRES (CLEARANCE WARNING ECU ASSEMBLY)

(a) Reconnect the J98 No. 6 CAN junction connector.

(b) Disconnect the J38 clearance warning ECU connector.

*a	Front view of wire harness connector (to Clearance Warning ECU Assembly)

Standard Resistance:

Tester Connection	Condition	Specified Condition
J38-37 (CANH) - J38-38 (CANL)	Cable disconnected from negative (-) battery terminal	54 to 69 Ω

REPLACE CLEARANCE WARNING ECU ASSEMBLY

REPAIR OR REPLACE CAN BUS WIRE (CLEARANCE WARNING ECU ASSEMBLY - NO. 6 CAN JUNCTION CONNECTOR)

19.	CHECK FOR SHORT IN CAN BUS WIRES (NO. 6 CAN JUNCTION CONNECTOR)

(a) Disconnect the J98 No. 6 CAN junction connector.

(b) Measure the resistance according to the value(s) in the table below.

DLC3

Front view of wire harness connector

(to No. 6 CAN Junction Connector)

to blind spot monitor sensor LH CAN main wire

to blind spot monitor sensor RH CAN main wire

to clearance warning ECU assembly CAN wire

Standard Resistance:

Tester Connection	Condition	Specified Condition
J98-3 (CANH) - J141-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
J98-14 (CANL) - J141-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
J98-3 (CANH) - J141-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
J98-14 (CANL) - J141-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
J98-1 (CANH) - J141-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
J98-12 (CANL) - J141-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
J98-1 (CANH) - J141-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
J98-12 (CANL) - J141-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
J98-2 (CANH) - J141-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
J98-13 (CANL) - J141-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
J98-2 (CANH) - J141-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
J98-13 (CANL) - J141-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher

Result	Proceed to
OK	A
NG (to blind spot monitor sensor LH CAN main wire)	B
NG (to blind spot monitor sensor RH CAN main wire)	C
NG (to clearance warning ECU assembly CAN wire)	D

REPLACE NO. 6 CAN JUNCTION CONNECTOR

GO TO STEP 21

GO TO STEP 22

20.	CHECK FOR SHORT IN CAN BUS WIRES (BLIND SPOT MONITOR SENSOR LH)

(a) Reconnect the J98 No. 6 CAN junction connector.

(b) Disconnect the X2 blind spot monitor sensor LH connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
X2-1 (CA2P) - J141-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
X2-6 (CA2N) - J141-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
X2-1 (CA2P) - J141-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
X2-6 (CA2N) - J141-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher

DLC3

Front view of wire harness connector

(to Blind Spot Monitor Sensor LH)

REPLACE BLIND SPOT MONITOR SENSOR LH

REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (BLIND SPOT MONITOR SENSOR LH - NO. 6 CAN JUNCTION CONNECTOR)

21.	CHECK FOR SHORT IN CAN BUS WIRES (BLIND SPOT MONITOR SENSOR RH)

(a) Reconnect the J98 No. 6 CAN junction connector.

(b) Disconnect the W2 blind spot monitor sensor RH connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
W2-1 (CA2P) - J141-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
W2-6 (CA2N) - J141-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
W2-1 (CA2P) - J141-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
W2-6 (CA2N) - J141-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher

DLC3

Front view of wire harness connector

(to Blind Spot Monitor Sensor RH)

REPLACE BLIND SPOT MONITOR SENSOR RH

REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (BLIND SPOT MONITOR SENSOR RH - NO. 6 CAN JUNCTION CONNECTOR)

22.	CHECK FOR SHORT IN CAN BUS WIRES (CLEARANCE WARNING ECU ASSEMBLY)

(a) Reconnect the J98 No. 6 CAN junction connector.

(b) Disconnect the J38 clearance warning ECU connector.

DLC3

Front view of wire harness connector

(to Clearance Warning ECU Assembly)

Standard Resistance:

Tester Connection	Condition	Specified Condition
J38-37 (CANH) - J141-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
J38-38 (CANL) - J141-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
J38-37 (CANH) - J141-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
J38-38 (CANL) - J141-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher

REPLACE CLEARANCE WARNING ECU ASSEMBLY

REPAIR OR REPLACE CAN BUS WIRE (CLEARANCE WARNING ECU ASSEMBLY - NO. 6 CAN JUNCTION CONNECTOR)

Control Module Communication Bus "A" Off (U0073,U0100,U0124,U0126,U0129,U0140,U0155,U0164)

DESCRIPTION These DTCs are stored if there is a malfunction in the CAN communication system connected to the clearance warning ECU assembly. HINT: If CAN communication system DTCs are stored, they may ...

CAN Communication Failure (Message Registry) (U1000)

DESCRIPTION When the clearance warning ECU assembly determines that the CAN communication circuit is malfunctioning during self diagnosis, DTC U1000 is stored. DTC No. Detection Item DTC Detect ...

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Lexus RX (RX 350L, RX450h) 2016-2024 Repair Manual: Lost Communication with Blind Spot Monitor Slave Module (U0232,U0233)

Control Module Communication Bus "A" Off (U0073,U0100,U0124,U0126,U0129,U0140,U0155,U0164)

CAN Communication Failure (Message Registry) (U1000)

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Lexus RX (RX 350L, RX450h) 2016-{YEAR} Owners Manual

Lexus RX (RX 350L, RX450h) 2016-{YEAR} Repair Manual