Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Lost Communication with Blind Spot Monitor Slave Module (U0232,U0233)

Lexus RX (RX 350L, RX450h) 2016-2025 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.

    Click here

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

1.

CHECK DTC

(a) Check for DTCs.

Click here

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
B

GO TO STEP 5

C

GO TO STEP 8

A

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.

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

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)
NG

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

3.

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

Click here

NG

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

4.

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

Click here

OK

REPLACE BLIND SPOT MONITOR SENSOR RH

NG

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.

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

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)
NG

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

6.

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

Click here

NG

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

7.

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

Click here

OK

REPLACE BLIND SPOT MONITOR SENSOR LH

NG

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.

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

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

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

*1

DLC3

*a

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
B

GO TO STEP 11

C

GO TO STEP 15

D

GO TO STEP 19

A

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)
NG

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

10.

CHECK DTC

(a) Clear the DTCs.

Click here

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

(b) Check for DTCs.

Click here

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
A

REPLACE CLEARANCE WARNING ECU ASSEMBLY
B

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
A

REPLACE NO. 6 CAN JUNCTION CONNECTOR
C

GO TO STEP 13

D

GO TO STEP 14

B

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)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

X2-1 (CA2P) - X2-6 (CA2N)

Cable disconnected from negative (-) battery terminal

108 to 132 Ω
OK

REPLACE BLIND SPOT MONITOR SENSOR LH

NG

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)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

W2-1 (CA2P) -W2-6 (CA2N)

Cable disconnected from negative (-) battery terminal

108 to 132 Ω
OK

REPLACE BLIND SPOT MONITOR SENSOR RH

NG

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)

(c) 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
OK

REPLACE CLEARANCE WARNING ECU ASSEMBLY
NG

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
A

REPLACE NO. 6 CAN JUNCTION CONNECTOR
C

GO TO STEP 17

D

GO TO STEP 18

B

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)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

X2-1 (CA2P) - X2-6 (CA2N)

Cable disconnected from negative (-) battery terminal

108 to 132 Ω
OK

REPLACE BLIND SPOT MONITOR SENSOR LH

NG

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)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

W2-1 (CA2P) -W2-6 (CA2N)

Cable disconnected from negative (-) battery terminal

108 to 132 Ω
OK

REPLACE BLIND SPOT MONITOR SENSOR RH

NG

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)

(c) 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
OK

REPLACE CLEARANCE WARNING ECU ASSEMBLY
NG

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.

*1

DLC3

-

-

*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

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
A

REPLACE NO. 6 CAN JUNCTION CONNECTOR
C

GO TO STEP 21

D

GO TO STEP 22

B

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.

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

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

*1

DLC3

*a

Front view of wire harness connector

(to Blind Spot Monitor Sensor LH)
OK

REPLACE BLIND SPOT MONITOR SENSOR LH

NG

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.

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

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

*1

DLC3

*a

Front view of wire harness connector

(to Blind Spot Monitor Sensor RH)
OK

REPLACE BLIND SPOT MONITOR SENSOR RH

NG

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.

*1

DLC3

*a

Front view of wire harness connector

(to Clearance Warning ECU Assembly)

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

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
OK

REPLACE CLEARANCE WARNING ECU ASSEMBLY
NG

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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