Last Modified: 12-11-2024 6.11:8.1.0 Doc ID: RM1000000028ABT
Model Year Start: 2023 Model: GR Corolla Prod Date Range: [11/2022 -           ]
Title: NETWORKING: CAN COMMUNICATION SYSTEM (for Gasoline Model): Bus Buffer ECU Communication Stop Mode; 2023 - 2025 MY Corolla Corolla Hatchback GR Corolla [11/2022 -        ]

Bus Buffer ECU Communication Stop Mode

DESCRIPTION

Detection Item

Symptom

Trouble Area

Bus Buffer ECU Communication Stop Mode

Communication stop for "Remote Engine Starter" is indicated on the "Communication Bus Check" screen of the GTS.

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  • 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.

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  • 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 the ignition switch is turned off, there may be a waiting time before disconnecting the negative (-) battery terminal.

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  • When disconnecting and reconnecting the battery.

    HINT:

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

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

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  • 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.

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  • 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.

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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 (-) 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 (-) 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)

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