CAN COMMUNICATION SYSTEM ECM Communication Stop Mode

DESCRIPTION

Detection Item Symptom Trouble Area
ECM Communication Stop Mode

Either condition is met:


  • Communication stop for "ECM (Engine)" is indicated on the "Communication Bus Check" screen of the GTS.

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

  • Power source circuit of ECM

  • ECM main line or connector

  • ECM

WIRING DIAGRAM

B001N4NE27

CAUTION / NOTICE / HINT

Note


  • 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 power 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 turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work.

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  • 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.

Tech Tips


  • 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)


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

    2. B001MJGE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to ECM)

      Disconnect the A60 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A60-13 (CANH) - A60-5 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (ECM MAIN LINE)

    OK

  2. CHECK ECM POWER SOURCE CIRCUIT


    1. Check the ECM power source circuit.


      Result
      Result Proceed to
      OK (for 2ZR-FXE) A
      OK (for 5ZR-FXE) B
      NG C

    A

    REPLACE ECM Click here

    B

    REPLACE ECM Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)