Last Modified: 08-22-2025 6.11:8.1.0 Doc ID: RM10000000259OW
Model Year Start: 2023 Model: Corolla Prod Date Range: [09/2022 -           ]
Title: NETWORKING: CAN COMMUNICATION SYSTEM (for HV Model): ECM Communication Stop Mode; 2023 - 2026 MY Corolla Corolla HV [09/2022 -        ]

ECM Communication Stop Mode

DESCRIPTION

Detection Item

Symptom

Trouble Area

ECM Communication Stop Mode

Communication stop for "ECM (Engine)" 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 - 2026 MY Corolla Corolla HV [11/2022 -        ]; NETWORKING: CAN COMMUNICATION SYSTEM (for HV Model): DIAGNOSIS SYSTEM

  • ECM main line or connector
  • Power source circuit of ECM
  • ECM ground circuit
  • ECM

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 - 2026 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 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 (-) auxiliary battery terminal.

    Click here 2023 - 2026 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 - 2026 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 - 09/2024]; SETUP: WHEN REPLACING OR REMOVING/INSTALLING PARTS: WORK PROCEDURE 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2024 - 08/2025]; SETUP: WHEN REPLACING OR REMOVING/INSTALLING PARTS: WORK PROCEDURE 2026 MY Corolla Corolla Hatchback Corolla HV GR Corolla [08/2025 -        ]; 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 - 2026 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.

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 FOR OPEN IN CAN BUS LINES (ECM MAIN LINE)

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

(b) Disconnect the A46 ECM connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A46-9 (CFDH) - A46-10 (CFDL)

Cable disconnected from negative (-) auxiliary battery terminal

108 to 132 Ω

*a

Front view of wire harness connector

(to ECM)
NG

REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (ECM)
OK

2.

CHECK ECM POWER SOURCE CIRCUIT

(a) Check the ECM power source circuit.

Click here 2023 - 2026 MY Corolla Corolla HV [09/2022 -        ]; 2ZR-FXE (ENGINE CONTROL): SFI SYSTEM: ECM Power Source Circuit

OK

REPLACE ECM 2023 MY Corolla Corolla HV [09/2022 - 11/2022]; 2ZR-FXE (ENGINE CONTROL): ECM: REMOVAL 2023 - 2026 MY Corolla Corolla HV [11/2022 -        ]; 2ZR-FXE (ENGINE CONTROL): ECM: REMOVAL

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)