Last Modified: 05-08-2025 6.11:8.1.0 Doc ID: RM100000002PY4I
Model Year Start: 2024 Model: RAV4 Prod Date Range: [10/2023 - 11/2024]
Title: NETWORKING: CAN COMMUNICATION SYSTEM (for Gasoline Model): Bus Buffer ECU Communication Stop Mode; 2024 MY RAV4 [10/2023 - 11/2024]

Bus Buffer ECU Communication Stop Mode

DESCRIPTION

Detection Item

Symptom

Trouble Area

Bus Buffer ECU Communication Stop Mode

Any of the following conditions are met:

  • Communication stop for "Accessory Gateway" is indicated on the "Communication Bus Check" screen of the Techstream.

    Click here 2022 - 2025 MY RAV4 [12/2021 -        ]; NETWORKING: CAN COMMUNICATION SYSTEM (for Gasoline Model): PROBLEM SYMPTOMS TABLE

  • Communication stop history for "Accessory Gateway" is indicated on the "Communication Bus Check (Detail)" screen of the Techstream. (The Lost Communication Time value for "Accessory Gateway" is 6 or more.)

    Click here 2022 - 2025 MY RAV4 [12/2021 -        ]; NETWORKING: CAN COMMUNICATION SYSTEM (for Gasoline Model): PROBLEM SYMPTOMS TABLE

  • Communication system DTCs (DTCs that start with U) that correspond to "Bus Buffer ECU Communication Stop Mode" in "DTC Combination Table" are output.

    Click here 2024 - 2025 MY RAV4 [10/2023 -        ]; NETWORKING: CAN COMMUNICATION SYSTEM (for Gasoline Model): DTC COMBINATION TABLE

  • Option connector (bus buffer ECU) branch wire or connector
  • Option connector (bus buffer ECU)

WIRING DIAGRAM

CAUTION / NOTICE / HINT

CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.

NOTICE:

  • Because the order of diagnosis is important to allow correct diagnosis, make sure to begin troubleshooting using How to Proceed with Troubleshooting when CAN communication system related DTCs are output.

    Click here 2019 - 2025 MY RAV4 [11/2018 -        ]; NETWORKING: CAN COMMUNICATION SYSTEM (for Gasoline Model): HOW TO PROCEED WITH TROUBLESHOOTING

  • Before measuring the resistance of the CAN bus, turn the ignition 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 10 minutes or more before measuring the resistance.
  • After turning the ignition 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 2019 - 2025 MY RAV4 RAV4 HV [11/2018 -        ]; INTRODUCTION: REPAIR INSTRUCTION: PRECAUTION

  • Some parts must be initialized and set when replacing or removing and installing parts.

    Click here 2024 - 2025 MY RAV4 RAV4 HV [10/2023 -        ]; INTRODUCTION: REPAIR INSTRUCTION: INITIALIZATION

  • After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output again.

    DTC check procedure: Turn the ignition switch to ON and wait for 1 minute or more. Then operate the suspected malfunctioning system and drive the vehicle at 60 km/h (37 mph) or more for 5 minutes or more.

  • After the repair, perform the CAN bus check and check that all the ECUs and sensors connected to the CAN communication system are displayed.

    Click here 2024 MY RAV4 [10/2023 - 11/2024]; NETWORKING: CAN COMMUNICATION SYSTEM (for Gasoline Model): DIAGNOSIS SYSTEM

HINT:

  • Before disconnecting related connectors for inspection, push in on each connector body to check that the connector is not loose or disconnected.
  • When a connector is disconnected, check that the terminals and connector body are not cracked, deformed or corroded.

PROCEDURE

1.

CHECK OPTIONS

(a) Check whether dealer installed options that support CAN communication are installed.

Result

Proceed to

Installed

A

Not installed

B
B

GO TO STEP 3

A

2.

CHECK FOR OPEN IN CAN BUS WIRE (OPTION CONNECTOR [BUS BUFFER ECU] BRANCH WIRE)

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

(b) Disconnect the option connector (bus buffer ECU).*

*: When a dealer-installed option is installed

*a

Front view of wire harness connector

(to Option Connector [Bus Buffer ECU])

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

G127-2 (CANP) - G127-1 (CANN)

Cable disconnected from negative (-) battery terminal

54 to 69 Ω
OK

CHECK DEALER-INSTALLED OPTION
NG

REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR

3.

CHECK FOR OPEN IN CAN BUS WIRE (OPTION CONNECTOR [BUS BUFFER ECU] BRANCH WIRE)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

*: When a dealer-installed option is installed

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Central Gateway / Utility / Initialization.

Body Electrical > Central Gateway > Utility

Tester Display

Initialization

(e) Enter the following menus: Body Electrical / Main Body / Utility / Initialization.

for Type A:

Body Electrical > Main Body > Utility

Tester Display

Initialization

for Type B:

Body Electrical > Main Body > Utility

Tester Display

Initialization

(f) Enter the following menus: Body Electrical / Main Body / Clear DTCs.

for Type A:

Body Electrical > Main Body > Clear DTCs

for Type B:

Body Electrical > Main Body > Clear DTCs

(g) Enter the following menus: Body Electrical / Main Body / Trouble Codes.

for Type A:

Body Electrical > Main Body > Trouble Codes

for Type B:

Body Electrical > Main Body > Trouble Codes

Result

Proceed to

DTC U1117 is not output from main body ECU (multiplex network body ECU)

A

DTC U1117 is output from main body ECU (multiplex network body ECU)

B
A

END
B

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)