CAN COMMUNICATION SYSTEM(w/o Central Gateway ECU) 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 of the GTS

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

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  • ECM main line or connector

  • Power source circuit of ECM

  • ECM ground circuit

  • ECM

WIRING DIAGRAM

A01D3WSE05
A01D5XYE05
A01D4OZE02
A01D4CLE03
A01D463E03

CAUTION / NOTICE / HINT

Note


  • 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 negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.

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  • 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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  • 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 20 seconds or more, and then drive the vehicle at a speed of 20 km/h (12 mph) 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.

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Tech Tips


  • Operating the ignition switch, any other switches or a door triggers related ECU and sensor communication on the CAN. This communication will cause the resistance value to change.

  • 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 VEHICLE TYPE


    1. Check vehicle type.

      Result
      Result Proceed to
      for 1NR-FE, 1ZR-FAE, 1ZR-FE or 2ZR-FE engine A
      for 1ND-TV engine B
      for 1AD-FTV engine C

    B

    CHECK FOR OPEN IN CAN BUS LINES (ECM MAIN LINE) Click here

    C

    CHECK FOR OPEN IN CAN BUS LINES (ECM MAIN LINE) Click here

    A

  2. CHECK FOR OPEN IN CAN BUS LINES (ECM MAIN LINE)


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

    2. A01D54FC17
      *a

      Front view of wire harness connector

      (to ECM)

      Disconnect the A50 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A50-13 (CANH) - A50-26 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Result
      OK
      NG

    NG

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

    OK

  3. CHECK ECM POWER SOURCE CIRCUIT


    1. Check the ECM power source circuit.


      Result
      Result Proceed to
      OK (for 1NR-FE engine) A
      OK (for 1ZR-FAE engine) B
      OK (for 1ZR-FE engine) C
      OK (for 2ZR-FE engine) D
      NG E

    A

    REPLACE ECM Click here

    B

    REPLACE ECM Click here

    C

    REPLACE ECM Click here

    D

    REPLACE ECM Click here

    E

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

  4. CHECK FOR OPEN IN CAN BUS LINES (ECM MAIN LINE)


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

    2. A01D6GKC09
      *A for LHD
      *B for RHD
      *a

      Front view of wire harness connector

      (to ECM)

      Disconnect the A101 ECM connector.

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

      Standard Resistance (for LHD)
      Tester Connection Condition Specified Condition
      A101-3 (CANH) - A101-4 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Standard Resistance (for RHD)
      Tester Connection Condition Specified Condition
      A101-3 (CANH) - A101-4 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Result
      OK
      NG

    NG

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

    OK

  5. CHECK ECM POWER SOURCE CIRCUIT


    1. Check the ECM power source circuit.

      Click here

      Result
      Result
      OK
      NG

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

  6. CHECK FOR OPEN IN CAN BUS LINES (ECM MAIN LINE)


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

    2. A01D68EC02
      *a

      Front view of wire harness connector

      (to ECM)

      Disconnect the A118 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A118-7 (CANH) - A118-6 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Result
      OK
      NG

    NG

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

    OK

  7. CHECK ECM POWER SOURCE CIRCUIT


    1. Check the ECM power source circuit.

      Click here

      Result
      Result
      OK
      NG

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)