Last Modified: 08-21-2023 6.11:8.1.0 Doc ID: RM100000001B1XN
Model Year Start: 2019 Model: Avalon Prod Date Range: [04/2018 -           ]
Title: PARK ASSIST / MONITORING: BLIND SPOT MONITOR SYSTEM (for Gasoline Model): U1331; Software Incompatibility with Body Control Module "B"; 2019 - 2022 MY Avalon [04/2018 -        ]

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.

Blind Spot Monitor Master

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 RH

Blind Spot Monitor Slave

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

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 Registration.

    w/ Smart Key System: Click here 2019 - 2020 MY Avalon [04/2018 - 08/2020]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): REGISTRATION 2021 - 2022 MY Avalon [08/2020 -        ]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): REGISTRATION

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) 2019 - 2021 MY Avalon Avalon HV [04/2018 - 08/2021]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL 2022 MY Avalon Avalon HV [08/2021 -        ]; 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 RH

C

REPLACE BLIND SPOT MONITOR SENSOR LH