Last Modified: 07-31-2024 6.11:8.1.0 Doc ID: RM100000001H942
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)): U1331; Software Incompatibility with Body Control Module "B"; 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]

DTC

U1331

Software Incompatibility with Body Control Module "B"

DESCRIPTION

This DTC is stored when the destination information of the main body ECU (multiplex network body ECU) does not match that of the blind spot monitor sensors.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

U1331

Software Incompatibility with Body Control Module "B"

Destination information of the main body ECU and blind spot monitor sensor do not match
  • Main body ECU (multiplex network body ECU)
  • Blind spot monitor sensor LH
  • Blind spot monitor sensor RH

CAUTION / NOTICE / HINT

NOTICE:

  • When checking for DTCs, make sure that the blind spot monitor system is on.
  • Before replacing the main body ECU (multiplex network body ECU), refer to Service Bulletin.

PROCEDURE

1.

CONFIRM PART NUMBER (MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU))

(a) Check the main body ECU (multiplex network body ECU) part number.

(1) Check if the part number of the main body ECU (multiplex network body ECU) installed on the vehicle is correct.

OK:

The part number is correct.

NG

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 03/2019]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2019 - 09/2022]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL

OK

2.

CHECK DTC

(a) Clear the DTCs.

Body Electrical > Blind Spot Monitor Master > Clear DTCs

Body Electrical > Blind Spot Monitor Slave > Clear DTCs

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

Body Electrical > Blind Spot Monitor Master > Trouble Codes

Body Electrical > Blind Spot Monitor Slave > Trouble Codes

Result

Proceed to

No DTCs are output

A

DTC U1331 is output ("Blind Spot Monitor Master")

B

DTC U1331 is output ("Blind Spot Monitor Slave")

C
A

USE SIMULATION METHOD TO CHECK

B

REPLACE BLIND SPOT MONITOR SENSOR LH

C

REPLACE BLIND SPOT MONITOR SENSOR RH