CAN COMMUNICATION SYSTEM(for RHD without 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 "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

B001ZX2E11
B001Z15E10

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 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.

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. for 1UR-FE, 1GR-FE:


      1. B001WC3E02
        Text in Illustration
        *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
        Tester Connection Condition Specified Condition
        A52-10 (CANH) - A52-11 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω

    2. for 1VD-FTV:


      1. B001X0IE02
        Text in Illustration
        *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
        Tester Connection Condition Specified Condition
        A52-41 (CANH) - A52-49 (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. for 1UR-FE, 1GR-FE:


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

        B00202OE01
        Text in Illustration
        *a

        Front view of wire harness connector

        (to ECM)

        		 - -

        Note

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

      2. Disconnect the ECM connector.

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

        Standard Voltage
        Tester Connection Condition Specified Condition
        A52-1 (BATT) - Body ground Always 11 to 14 V
        A52-3 (+B) - Body ground Battery positive (+) voltage applied to terminal A52-34 (MREL) 11 to 14 V
        A52-2 (+B2) - Body ground Battery positive (+) voltage applied to terminal A52-34 (MREL) 11 to 14 V
        A52-28 (IGSW) - Body ground Ignition switch ON 11 to 14 V

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        A52-31 (EC) - Body ground Always Below 1 Ω
        C46-42 (E02) - Body ground Always Below 1 Ω
        C46-43 (E01) - Body ground Always Below 1 Ω
        C46-82 (ME01) - Body ground Always Below 1 Ω
        C46-81 (E1) - Body ground Always Below 1 Ω
        C46-23 (E04) - Body ground Always Below 1 Ω
        C46-21 (E05) - Body ground Always Below 1 Ω

    2. for 1VD-FTV:


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

        B001ZSDE01
        Text in Illustration
        *a

        Front view of wire harness connector

        (to ECM)

        		 - -

        Note

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

      2. Disconnect the ECM connector.

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

        Standard Voltage
        Tester Connection Condition Specified Condition
        A52-20 (BATT) - Body ground Always 11 to 14 V
        A52-2 (+B) - Body ground Battery positive (+) voltage applied to terminal A52-44 (MREL) 11 to 14 V
        A52-1 (+B2) - Body ground Battery positive (+) voltage applied to terminal A52-44 (MREL) 11 to 14 V
        A52-28 (IGSW) - Body ground Ignition switch ON 11 to 14 V

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        A52-32 (EC) - Body ground Always Below 1 Ω
        C46-21 (E02) - Body ground Always Below 1 Ω
        C46-22 (E01) - Body ground Always Below 1 Ω
        C46-81 (E1) - Body ground Always Below 1 Ω
        C46-44 (E04) - Body ground Always Below 1 Ω
        C46-23 (E05) - Body ground Always Below 1 Ω
        Result
        Result Proceed to
        OK (for 1UR-FE) A
        OK (for 1GR-FE) B
        OK (for 1VD-FTV) 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