Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM10000000259R2
Model Year Start: 2023 Model: Corolla Prod Date Range: [09/2022 -           ]
Title: NETWORKING: CAN COMMUNICATION SYSTEM (for HV Model): Bus Buffer ECU Communication Stop Mode; 2023 - 2025 MY Corolla Corolla HV [09/2022 -        ]

Bus Buffer ECU Communication Stop Mode

DESCRIPTION

Detection Item

Symptom

Trouble Area

Bus Buffer ECU Communication Stop Mode

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

2023 MY Corolla Corolla HV [09/2022 - 11/2022]; NETWORKING: CAN COMMUNICATION SYSTEM (for HV Model): DIAGNOSIS SYSTEM 2023 - 2025 MY Corolla Corolla HV [11/2022 -        ]; NETWORKING: CAN COMMUNICATION SYSTEM (for HV Model): DIAGNOSIS SYSTEM

  • Option connector (bus buffer ECU) main line or connector
  • CAN compatible optional device
  • Main body ECU (multiplex network body 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 2023 - 2025 MY Corolla Corolla HV [09/2022 -        ]; NETWORKING: CAN COMMUNICATION SYSTEM (for HV 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 (-) auxiliary battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.
  • After the ignition switch is turned off, there may be a waiting time before disconnecting the negative (-) auxiliary battery terminal.

    Click here 2023 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2022 -        ]; SETUP: WHEN DISCONNECTING OR RECONNECTING BATTERY TERMINAL: BEFORE DISCONNECTING BATTERY

  • When disconnecting and reconnecting the auxiliary battery.

    HINT:

    When disconnecting and reconnecting the auxiliary battery, there is an automatic learning function that completes learning when the respective system is used.

    Click here 2023 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2022 - 11/2022]; SETUP: WHEN DISCONNECTING OR RECONNECTING BATTERY TERMINAL: AUTOMATIC LEARNING CHART 2023 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [11/2022 -        ]; SETUP: WHEN DISCONNECTING OR RECONNECTING BATTERY TERMINAL: AUTOMATIC LEARNING CHART

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

    Click here 2023 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2022 - 11/2022]; SETUP: WHEN REPLACING OR REMOVING/INSTALLING PARTS: WORK PROCEDURE 2023 MY Corolla Corolla Hatchback Corolla HV GR Corolla [11/2022 - 03/2023]; SETUP: WHEN REPLACING OR REMOVING/INSTALLING PARTS: WORK PROCEDURE 2023 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2023 - 08/2023]; SETUP: WHEN REPLACING OR REMOVING/INSTALLING PARTS: WORK PROCEDURE 2024 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [08/2023 -        ]; SETUP: WHEN REPLACING OR REMOVING/INSTALLING PARTS: WORK PROCEDURE

  • 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 as normal.

    Click here 2023 MY Corolla Corolla HV [09/2022 - 11/2022]; NETWORKING: CAN COMMUNICATION SYSTEM (for HV Model): DIAGNOSIS SYSTEM 2023 - 2025 MY Corolla Corolla HV [11/2022 -        ]; NETWORKING: CAN COMMUNICATION SYSTEM (for HV Model): DIAGNOSIS SYSTEM

  • Inspect the fuses for circuits related to this system before performing the following procedure.
  • Before replacing the main body ECU (multiplex network body ECU), refer to Registration.

    Click here 2023 - 2025 MY Corolla Corolla HV [09/2022 -        ]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): REGISTRATION

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 VEHICLE TYPE

(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 LINES (OPTION CONNECTOR (BUS BUFFER ECU) MAIN LINE)

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

(b) Disconnect the I174 option connector (bus buffer ECU) connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

I174-2 (CAN+) - I174-1 (CAN-)

Cable disconnected from negative (-) auxiliary battery terminal

108 to 132 Ω

*a

Front view of wire harness connector

(to Option Connector (Bus Buffer ECU))
OK

REPAIR OR REPLACE CAN COMPATIBLE OPTIONAL DEVICE
NG

REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (OPTION CONNECTOR (BUS BUFFER ECU))

3.

CHECK FOR DTC

(a) Initialize the ECU.

Body Electrical > Central Gateway > Utility

Tester Display

Initialization

Body Electrical > Main Body > Utility

Tester Display

Initialization

(b) Clear the DTCs.

Body Electrical > Main Body > Clear DTCs

(c) Read the DTCs.

Body Electrical > Main Body > Trouble Codes

Result

Proceed to

DTC U111787 is not output from main body ECU (multiplex network body ECU)

A

DTC U111787 is output from main body ECU (multiplex network body ECU)

B
A

END
B

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) 2023 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2022 - 11/2022]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL 2023 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [11/2022 -        ]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL