Lexus ES: Lost Communication with Blind Spot Monitor Slave Module (U0232)

Lexus ES (XZ10) Service Manual / Audio & Visual & Telematics / Park Assist / Monitoring / Blind Spot Monitor System (for Gasoline Model) / Lost Communication with Blind Spot Monitor Slave Module (U0232)

DESCRIPTION

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

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
U0232	Lost Communication with Blind Spot Monitor Slave Module	The blind spot monitor sensor (master) cannot receive signals from the blind spot monitor sensor (slave)	Open or short in CAN bus main wire or connector Open or short in No. 24 CAN junction connector 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 Harness and connector

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

When checking for DTCs, make sure that the blind spot monitor system is turned on.
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

1.	CONFIRM MODEL

(a) Choose the model to be inspected.

Result	Proceed to
w/ Parking Support Brake System	A
w/o Parking Support Brake System	B

GO TO STEP 3

2.	CHECK DTC OUTPUT (PARKING SUPPORT BRAKE SYSTEM)

(a) Using the Techstream, check for DTCs according to the prompts on the screen.

Click here

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

Standard:

The clearance warning ECU assembly does not output DTCs U0232 and U0233 simultaneously.

GO TO PARKING SUPPORT BRAKE SYSTEM (DTC U0232)

3.	CHECK CAN BUS MAIN WIRE

(a) Turn the engine switch off.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition	Result
N100-3 (CANH) -N100-14 (CANL)	Cable disconnected from negative (-) battery terminal	54 to 69 Ω	Below 54 Ω: Short circuit between bus lines
N100-3 (CANH) -N100-14 (CANL)	Cable disconnected from negative (-) battery terminal	54 to 69 Ω	70 Ω or more: Open circuit in main bus lines
N100-3 (CANH) - G57-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher	Below 200 Ω: CANH short to ground
N100-14 (CANL) - G57-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher	Below 200 Ω: CANL short to ground
N100-3 (CANH) - G57-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher	Below 6 kΩ: CANH +B short
N100-14 (CANL) - G57-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher	Below 6 kΩ: CANL +B short

DLC3

Component with harness connected

(No. 24 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 9

GO TO STEP 12

GO TO STEP 15

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

(a) Disconnect the R5 blind spot monitor sensor LH connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
R5-10 (BLGD) - Body ground	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

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

(a) Disconnect the R5 blind spot monitor sensor LH connector.

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
R5-5 (BLB) - Body ground	Engine switch on (IG)	11 to 14 V
R5-5 (BLB) - Body ground	Engine switch off	Below 1 V

REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK DTC

(a) Reconnect the cable to the negative (-) battery terminal.

(b) Turn the engine switch off.

(d) Check for DTCs.

Click here

Body Electrical > Blind Spot Monitor Master > Trouble Codes

OK:

No DTCs are output.

USE SIMULATION METHOD TO CHECK

7.	REPLACE BLIND SPOT MONITOR SENSOR LH

(a) Replace the blind spot monitor sensor LH.

Click here

8.	RECHECK DTC

(a) Clear the DTCs.

Click here

Body Electrical > Blind Spot Monitor Master > Clear DTCs

(b) Recheck for DTCs and check if the same DTC is output again.

Body Electrical > Blind Spot Monitor Master > Trouble Codes

OK:

No DTCs are output.

END

REPLACE BLIND SPOT MONITOR SENSOR RH

9.	CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 24 CAN JUNCTION CONNECTOR)

(a) Disconnect the N100 No. 24 CAN junction connector.

Front view of wire harness connector

(to No. 24 CAN Junction Connector)

to Blind Spot Monitor Sensor LH CAN main wire

to Blind Spot Monitor Sensor RH CAN main wire

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
N100-3 (CANH) - N100-14 (CANL)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω
N100-2 (CANH) - N100-13 (CANL)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω

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

REPLACE NO. 24 CAN JUNCTION CONNECTOR

GO TO STEP 11

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

(a) Reconnect the N100 No. 24 CAN junction connector.

(b) Disconnect the R5 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
R5-1 (CA2P) - R5-6 (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. 24 CAN JUNCTION CONNECTOR)

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

(a) Reconnect the N100 No. 24 CAN junction connector.

(b) Disconnect the R4 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
R4-1 (CA2P) -R4-6 (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. 24 CAN JUNCTION CONNECTOR)

12.	CHECK FOR SHORT IN CAN BUS WIRES (NO. 24 CAN JUNCTION CONNECTOR)

(a) Disconnect the N100 No. 24 CAN junction connector.

Front view of wire harness connector

(to No. 24 CAN Junction Connector)

to Blind Spot Monitor Sensor LH CAN main wire

to Blind Spot Monitor Sensor RH CAN main wire

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
N100-3 (CANH) - N100-14 (CANL)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω
N100-2 (CANH) - N100-13 (CANL)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω

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

REPLACE NO. 24 CAN JUNCTION CONNECTOR

GO TO STEP 14

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

(a) Reconnect the N100 No. 24 CAN junction connector.

(b) Disconnect the R5 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
R5-1 (CA2P) - R5-6 (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. 24 CAN JUNCTION CONNECTOR)

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

(a) Reconnect the N100 No. 24 CAN junction connector.

(b) Disconnect the R4 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
R4-1 (CA2P) -R4-6 (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. 24 CAN JUNCTION CONNECTOR)

15.	CHECK FOR SHORT IN CAN BUS WIRES (NO. 24 CAN JUNCTION CONNECTOR)

(a) Disconnect the N100 No. 24 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. 24 CAN Junction Connector)

to Blind Spot Monitor Sensor LH CAN main wire

to Blind Spot Monitor Sensor RH CAN main wire

Standard Resistance:

Tester Connection	Condition	Specified Condition
N100-3 (CANH) - G57-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
N100-14 (CANL) - G57-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
N100-3 (CANH) - G57-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
N100-14 (CANL) - G57-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
N100-2 (CANH) - G57-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
N100-13 (CANL) - G57-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
N100-2 (CANH) - G57-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
N100-13 (CANL) - G57-16 (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

REPLACE NO. 24 CAN JUNCTION CONNECTOR

GO TO STEP 17

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

(a) Reconnect the N100 No. 24 CAN junction connector.

(b) Disconnect the R5 blind spot monitor sensor LH connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
R5-1 (CA2P) - G57-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
R5-6 (CA2N) - G57-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
R5-1 (CA2P) - G57-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
R5-6 (CA2N) - G57-16 (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. 24 CAN JUNCTION CONNECTOR)

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

(a) Reconnect the N100 No. 24 CAN junction connector.

(b) Disconnect the R4 blind spot monitor sensor RH connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
R4-1 (CA2P) - G57-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
R4-6 (CA2N) - G57-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
R4-1 (CA2P) - G57-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
R4-6 (CA2N) - G57-16 (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. 24 CAN JUNCTION CONNECTOR)

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