Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001H940
Model Year Start: 2020 Model: Corolla Prod Date Range: [01/2019 - 09/2022]
Title: PARK ASSIST / MONITORING: BLIND SPOT MONITOR SYSTEM (for HV Model (w/o Safe Exit Assist Function)): U0232; Lost Communication with Blind Spot Monitor Slave Module; 2020 - 2022 MY Corolla Corolla HV [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
  • Harness or 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 power 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 (-) auxiliary battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.
  • After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work.

    Click here 2019 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2018 -        ]; INTRODUCTION: REPAIR INSTRUCTION: PRECAUTION

HINT:

  • Operating the power 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 CAN BUS MAIN WIRE

(a) Turn the power 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

O57-1 (CA2P) - O57-6 (CA2N)

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

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
B

GO TO STEP 7

C

GO TO STEP 9

D

GO TO STEP 11

A

2.

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

Click here 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]; PARK ASSIST / MONITORING: BLIND SPOT MONITOR SYSTEM (for HV Model (w/o Safe Exit Assist Function)): Power Source Circuit+

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

3.

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

Click here 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]; PARK ASSIST / MONITORING: BLIND SPOT MONITOR SYSTEM (for HV Model (w/o Safe Exit Assist Function)): Power Source Circuit+

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

4.

CHECK DTC

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

(b) Turn the power switch off.

(c) Turn the power switch on (IG).

(d) Check for DTCs.

Body Electrical > Blind Spot Monitor Master > Trouble Codes

OK:

No DTCs are output.

OK

SYMPTOM SIMULATION

NG

5.

REPLACE BLIND SPOT MONITOR SENSOR RH

(a) Replace the blind spot monitor sensor RH.

Click here 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 09/2022]; PARK ASSIST / MONITORING: BLIND SPOT MONITOR SENSOR: REMOVAL

NEXT

6.

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.

OK

END
NG

REPLACE BLIND SPOT MONITOR SENSOR LH

7.

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)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

O58-1 (CA2P) -O58-6 (CA2N)

Cable disconnected from negative (-) battery terminal

108 to 132 Ω
OK

REPLACE BLIND SPOT MONITOR SENSOR RH

NG

8.

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
OK

REPLACE BLIND SPOT MONITOR SENSOR LH

NG

REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (BLIND SPOT MONITOR SENSOR LH - BLIND SPOT MONITOR SENSOR RH)

9.

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)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

O58-1 (CA2P) -O58-6 (CA2N)

Cable disconnected from negative (-) battery terminal

108 to 132 Ω
OK

REPLACE BLIND SPOT MONITOR SENSOR RH

NG

10.

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
OK

REPLACE BLIND SPOT MONITOR SENSOR LH

NG

REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (BLIND SPOT MONITOR SENSOR LH - BLIND SPOT MONITOR SENSOR RH)

11.

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.

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

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

*1

DLC3

*a

Front view of wire harness connector

(to blind spot monitor sensor RH)
OK

REPLACE BLIND SPOT MONITOR SENSOR RH

NG

12.

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

*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 - BLIND SPOT MONITOR SENSOR RH)