CAN COMMUNICATION SYSTEM ECM Communication Stop Mode

DESCRIPTION

Detection Item Symptom Trouble Area
ECM Communication Stop Mode

Either condition is met:


  • "ECM (Engine)" is not displayed on the "CAN Bus Check" screen Click here.

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

  • ECM CAN main wire or connector

  • Power source circuit of ECM

  • ECM ground circuit

  • ECM

WIRING DIAGRAM

A002PXOE02
A002P51E02

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 Click here.

  • 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, switches or opening or closing the doors. After that, disconnect the cable from the negative (-) battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.

  • After turning the ignition switch off, waiting time may be required before disconnecting the cable from the battery terminal. Therefore, make sure to read the disconnecting the cable from the battery terminal notice before proceeding with work Click here.

  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.

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

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

Tech Tips


  • Operating the ignition switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

  • Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below may help determine the cause of the malfunction.

PROCEDURE


  1. CHECK FOR OPEN IN CAN BUS WIRE (ECM CAN MAIN WIRE)


    1. A002O74E02
      Text in Illustration
      *A for 1ZR-FAE, 2ZR-FAE
      *B for 1WW
      *a

      Front view of wire harness connector

      (to ECM)

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

    2. Disconnect the ECM connector.

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

      Standard Resistance
      for 1ZR-FAE, 2ZR-FAE
      Tester Connection Condition Specified Condition
      A76-13 (CANH) - A76-26 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      for 1WW
      Tester Connection Condition Specified Condition
      A76-26 (CANH) - A76-25 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω

    NG

    REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO ECM (CANH, CANL)

    OK

  2. CHECK HARNESS AND CONNECTOR (ECM - BATTERY AND BODY GROUND)


    1. Connect the cable to the negative (-) battery terminal.

      Note

      When connecting the cable, some systems need to be initialized after the cable is reconnected Click here.

    2. for 1ZR-FAE, 2ZR-FAE:

      A002O7WE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to ECM)

      		 - -

      1. Disconnect the ECM connector.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        A76-32 (EC) - Body ground Always Below 1 Ω
        C111-26 (E04) - Body ground Always Below 1 Ω
        C111-28 (ME01) - Body ground Always Below 1 Ω
        C111-57 (E01) - Body ground Always Below 1 Ω
        C111-58 (E02) - Body ground Always Below 1 Ω
        C111-59 (E1) - Body ground Always Below 1 Ω

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

        Standard Voltage
        Tester Connection Condition Specified Condition
        C111-29 (+BM) - Body ground Always 11 to 14 V
        A76-1 (BATT) - Body ground Always 11 to 14 V
        A76-3 (+B2) - Body ground Battery positive (+) voltage applied to terminal A76-46 (MREL) 11 to 14 V
        A76-2 (+B) - Body ground Battery positive (+) voltage applied to terminal A76-46 (MREL) 11 to 14 V

    3. for 1WW:


      1. A002NFZE02
        Text in Illustration
        *a

        Front view of wire harness connector

        (to ECM)

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        A76-4 (E1) - Body ground Always Below 1 Ω
        A76-5 (E2) - Body ground Always Below 1 Ω
        A76-17 (E3) - Body ground Always Below 1 Ω
        A76-18 (E4) - Body ground Always Below 1 Ω

      2. Measure the voltage according to the value(s) in the table below.

        Standard Voltage
        Tester Connection Condition Specified Condition
        A76-15 (BATT) - Body ground Always 11 to 14 V
        A76-1 (+B3) - Body ground Battery positive (+) voltage applied to terminal A76-9 (MREL) 11 to 14 V
        A76-14 (+B2) - Body ground Battery positive (+) voltage applied to terminal A76-9 (MREL) 11 to 14 V
        A76-2 (+B) - Body ground Battery positive (+) voltage applied to terminal A76-9 (MREL) 11 to 14 V
      Result
      Result Proceed to
      OK (for 1ZR-FAE) A
      OK (for 2ZR-FAE) B
      OK (for 1WW) C
      NG D

    A

    REPLACE ECM Click here

    B

    REPLACE ECM Click here

    C

    REPLACE ECM Click here

    D

    REPAIR OR REPLACE HARNESS OR CONNECTOR