CAN COMMUNICATION SYSTEM(for LHD) ECM Communication Stop Mode

DESCRIPTION

Detection Item Symptom Trouble Area
ECM Communication Stop Mode

Either condition is met:


  • "ECM (Engine)" is not displayed on "CAN Bus Check".

    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


  • Power source or inside ECM

  • ECM CAN main wire or connector

  • ECM

WIRING DIAGRAM

A01GCGWE01
A01GAE3E02
A01GCGWE02

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.

  • DTC check procedure: Drive the vehicle for 50 seconds at a speed of 20 km/h (12 mph).

  • 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. A01GBX0C01
      *A for 2AR-FE, 3ZR-FAE, 3ZR-FE
      *B for 1AD-FTV, 2AD-FHV, 2AD-CCo, 2AD-DPF
      *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 2AR-FE, 3ZR-FAE, 3ZR-FE
      Tester Connection Connector Specified Condition
      A62-13 (CANH) - A62-26 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      for 1AD-FTV, 2AD-FHV, 2AD-CCo, 2AD-DPF
      Tester Connection Condition Specified Condition
      A61-7 (CANH) - A61-6 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    NG

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

    OK

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


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

      Note

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected.

      Click here

    2. for 2AR-FE:

      A01GDE6C20
      *a

      Front view of wire harness connector

      (to ECM)

      		 - -

      1. Disconnect the ECM connector.

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

        Standard Voltage
        Tester Connection Condition Specified Condition
        A62-1 (BATT) - Body ground Always 11 to 14 V
        A62-2 (+B) - Body ground Battery positive (+) voltage applied to terminal A62-46 (MREL) 11 to 14 V
        A62-3 (+B2) - Body ground Battery positive (+) voltage applied to terminal A62-46 (MREL) 11 to 14 V
        A62-37 (IGSW) - Body ground Ignition switch ON 11 to 14 V

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        B77-16 (E1) - Body ground Always Below 1 Ω
        B77-49 (E02) - Body ground Always Below 1 Ω
        B77-50 (E01) - Body ground Always Below 1 Ω
        B77-58 (ME01) - Body ground Always Below 1 Ω

    3. for 3ZR-FAE, 3ZR-FE:

      A01GDE6C24
      *a

      Front view of wire harness connector

      (to ECM)

      		 - -

      1. Disconnect the ECM connector.

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

        Standard Voltage
        Tester Connection Condition Specified Condition
        A62-1 (BATT) - Body ground Always 11 to 14 V
        A62-2 (+B) - Body ground Battery positive (+) voltage applied to terminal A62-46 (MREL) 11 to 14 V
        A62-3 (+B2) - Body ground Battery positive (+) voltage applied to terminal A62-46 (MREL) 11 to 14 V
        A62-37 (IGSW) - Body ground Ignition switch ON 11 to 14 V

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        B75-16 (E1) - Body ground Always Below 1 Ω
        B75-21 (E02) - Body ground Always Below 1 Ω
        B75-51 (E01) - Body ground Always Below 1 Ω
        B75-59 (ME01) - Body ground Always Below 1 Ω

    4. for 1AD-FTV, 2AD-FHV, 2AD-CCo, 2AD-DPF:

      A01GB27C04
      *a

      Front view of wire harness connector

      (to ECM)

      		 - -

      1. Disconnect the ECM connector.

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

        Standard Voltage
        Tester Connection Condition Specified Condition
        A61-2 (BATT) - Body ground Always 11 to 14 V
        A61-1 (+B) - Body ground Battery positive (+) voltage applied to terminal A61-45 (MREL) 11 to 14 V
        A61-20 (+B2) - Body ground Battery positive (+) voltage applied to terminal A61-45 (MREL) 11 to 14 V
        A61-25 (IGSW) - Body ground Ignition switch ON 11 to 14 V

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        B76-44 (E02) - Body ground Always Below 1 Ω
        B76-45 (E01) - Body ground Always Below 1 Ω
        B76-84 (ME01) - Body ground Always Below 1 Ω
        B76-109 (E1) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ECM for 2AR-FE: Click here
    REPLACE ECM for 3ZR-FAE: Click here
    REPLACE ECM for 3ZR-FE: Click here
    REPLACE ECM for 1AD-FTV: Click here
    REPLACE ECM for 2AD-FHV: Click here
    REPLACE ECM for 2AD-CCo, 2AD-DPF: Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR