PARK ASSIST / MONITORING: BLIND SPOT MONITOR SYSTEM (for Gasoline Model (w/o Safe Exit Assist Function)): U0232; Lost Communication with Blind Spot Monitor Slave Module; 2020 - 2022 MY Corolla Corolla Hatchback GR Corolla [01/2019

Last Modified: 05-13-2024	6.11:8.1.0	Doc ID: RM100000001ORMI
Model Year Start: 2020	Model: GR Corolla	Prod Date Range: [01/2019 - 09/2022]
Title: PARK ASSIST / MONITORING: BLIND SPOT MONITOR SYSTEM (for Gasoline Model (w/o Safe Exit Assist Function)): U0232; Lost Communication with Blind Spot Monitor Slave Module; 2020 - 2022 MY Corolla Corolla Hatchback GR Corolla [01/2019 - 09/2022]

DTC

U0232

Lost Communication with Blind Spot Monitor Slave Module

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 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. 19 junction connector 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 Wire harness or connector

WIRING DIAGRAM

for Hatchback Model

for Sedan Model

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.
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 MODEL

(a) Choose the model to be inspected.

Result	Proceed to
for Hatchback Model	A
for Sedan Model	B

GO TO STEP 17

2.	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
O96-2 (CANH) -O96-13 (CANL)	Cable disconnected from negative (-) battery terminal	54 to 69 Ω	Below 54 Ω: Short circuit between bus lines
O96-2 (CANH) -O96-13 (CANL)	Cable disconnected from negative (-) battery terminal	54 to 69 Ω	70 Ω or more: Open circuit in main bus lines
O96-2 (CANH) - I26-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher	Below 200 Ω: CANH short to ground
O96-13 (CANL) - I26-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher	Below 200 Ω: CANL short to ground
O96-2 (CANH) - I26-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher	Below 6 kΩ: CANH +B short
O96-13 (CANL) - I26-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher	Below 6 kΩ: CANL +B short

DLC3

Component with harness connected

(No. 19 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 8

GO TO STEP 11

GO TO STEP 14

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

(a) Disconnect the O58 blind spot monitor sensor RH connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
O58-10 (BRGD) - Body ground	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

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

(a) Disconnect the O58 blind spot monitor sensor RH connector.

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
O58-5 (BRB) - Body ground	Engine switch on (IG)	11 to 14 V
O58-5 (BRB) - 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.

Body Electrical > Blind Spot Monitor Master > Trouble Codes

OK:

No DTCs are output.

USE SIMULATION METHOD TO CHECK

6.	REPLACE BLIND SPOT MONITOR SENSOR RH

(a) Replace the blind spot monitor sensor RH with a new one.

Click here

7.	RECHECK DTC

(a) Clear the DTCs.

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 LH

8.	CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 19 JUNCTION CONNECTOR)

(a) Disconnect the O96 No. 19 junction connector.

Front view of wire harness connector

(to No. 19 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
O96-2 (CANH) - O96-13 (CANL)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω
O96-1 (CANH) - O96-12 (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. 19 JUNCTION CONNECTOR

GO TO STEP 10

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

(a) Reconnect the O96 No. 19 junction connector.

(b) Disconnect the O57 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
O57-1 (CA2P) - O57-6 (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. 19 CAN JUNCTION CONNECTOR)

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

(a) Reconnect the O96 No. 19 junction connector.

(b) Disconnect the O58 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
O58-1 (CA2P) -O58-6 (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. 19 JUNCTION CONNECTOR)

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

(a) Disconnect the O96 No. 19 junction connector.

Front view of wire harness connector

(to No. 19 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
O96-2 (CANH) - O96-13 (CANL)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω
O96-1 (CANH) - O96-12 (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. 19 JUNCTION CONNECTOR

GO TO STEP 13

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

(a) Reconnect the O96 No. 19 junction connector.

(b) Disconnect the O57 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
O57-1 (CA2P) - O57-6 (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. 19 JUNCTION CONNECTOR)

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

(a) Reconnect the O96 No. 19 junction connector.

(b) Disconnect the O58 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
O58-1 (CA2P) -O58-6 (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. 19 JUNCTION CONNECTOR)

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

(a) Disconnect the O96 No. 19 junction connector.

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

DLC3

Front view of wire harness connector

(to No. 19 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
O96-2 (CANH) - I26-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
O96-13 (CANL) - I26-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
O96-2 (CANH) - I26-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
O96-13 (CANL) - I26-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
O96-1 (CANH) - I26-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
O96-12 (CANL) - I26-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
O96-1 (CANH) - I26-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
O96-12 (CANL) - I26-16 (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. 19 JUNCTION CONNECTOR

GO TO STEP 16

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

(a) Reconnect the O96 No. 19 junction connector.

(b) Disconnect the O57 blind spot monitor sensor LH connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
O57-1 (CA2P) - I26-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
O57-6 (CA2N) - I26-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
O57-1 (CA2P) - I26-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
O57-6 (CA2N) - I26-16 (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. 19 JUNCTION CONNECTOR)

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

(a) Reconnect the O96 No. 19 junction connector.

(b) Disconnect the O58 blind spot monitor sensor RH connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
O58-1 (CA2P) - I26-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
O58-6 (CA2N) - I26-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
O58-1 (CA2P) - I26-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
O58-6 (CA2N) - I26-16 (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. 19 JUNCTION CONNECTOR)

17.	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
O57-1 (CA2P) - O57-6 (CA2N)	Cable disconnected from negative (-) battery terminal	54 to 69 Ω	Below 54 Ω: Short circuit between bus lines
O57-1 (CA2P) - O57-6 (CA2N)	Cable disconnected from negative (-) battery terminal	54 to 69 Ω	70 Ω or more: Open circuit in main bus lines
O57-1 (CA2P) - Body ground	Cable disconnected from negative (-) battery terminal	200 Ω or higher	Below 200 Ω: CA2P short to ground
O57-6 (CA2N) - Body ground	Cable disconnected from negative (-) battery terminal	200 Ω or higher	Below 200 Ω: CA2N short to ground
O57-1 (CA2P) - +B	Cable disconnected from negative (-) battery terminal	6 kΩ or higher	Below 6 kΩ: CA2P +B short
O57-6 (CA2N) - +B	Cable disconnected from negative (-) battery terminal	6 kΩ or higher	Below 6 kΩ: CA2N +B short

*a	Component with harness connected (Blind spot monitor sensor LH)

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 23

GO TO STEP 25

GO TO STEP 27

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

Click here

REPAIR OR REPLACE HARNESS OR CONNECTOR

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

Click here

REPAIR OR REPLACE HARNESS OR CONNECTOR

20.

CHECK DTC

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

(b) Turn the engine switch off.

(d) Check for DTCs.

Body Electrical > Blind Spot Monitor Master > Trouble Codes

OK:

No DTCs are output.

SYMPTOM SIMULATION

21.	REPLACE BLIND SPOT MONITOR SENSOR RH

(a) Replace the blind spot monitor sensor RH.

Click here

22.	RECHECK DTC

(a) Clear the DTCs.

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 LH

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

(a) Reconnect the O57 blind spot monitor sensor LH connector.

(b) Disconnect the O58 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
O58-1 (CA2P) -O58-6 (CA2N)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω

REPLACE BLIND SPOT MONITOR SENSOR RH

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

(a) Disconnect the O57 blind spot monitor sensor LH connector.

*a	Front view of wire harness connector (to blind spot monitor sensor LH)

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
O57-1 (CA2P) - O57-6 (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 - BLIND SPOT MONITOR SENSOR RH)

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

(a) Reconnect the O57 blind spot monitor sensor LH connector.

(b) Disconnect the O58 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
O58-1 (CA2P) -O58-6 (CA2N)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω

REPLACE BLIND SPOT MONITOR SENSOR RH

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

(a) Disconnect the O57 blind spot monitor sensor LH connector.

*a	Front view of wire harness connector (to blind spot monitor sensor LH)

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
O57-1 (CA2P) - O57-6 (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 - BLIND SPOT MONITOR SENSOR RH)

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

(a) Reconnect the O57 blind spot monitor sensor LH connector.

(b) Disconnect the O58 blind spot monitor sensor RH connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
O58-1 (CA2P) - I26-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
O58-6 (CA2N) - I26-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
O58-1 (CA2P) - I26-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
O58-6 (CA2N) - I26-16 (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

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

(a) Disconnect the O57 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
O57-1 (CA2P) - I26-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
O57-6 (CA2N) - I26-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
O57-1 (CA2P) - I26-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
O57-6 (CA2N) - I26-16 (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 - BLIND SPOT MONITOR SENSOR RH)