CAN COMMUNICATION SYSTEM(for RHD without Central Gateway ECU) Main Body ECU Communication Stop Mode

DESCRIPTION

Detection Item Symptom Trouble Area
Main Body ECU Communication Stop Mode

Either Condition is met:


  • "Main Body" is not displayed on the "Bus Check" screen Click here.

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

  • Main body ECU (multiplex network body ECU) CAN branch wire or connector

  • Power source circuit of main body ECU (multiplex network body ECU)

  • Power source circuit of cowl side junction block LH

  • Main body ECU (multiplex network body ECU) ground circuit

  • Cowl side junction block LH ground circuit

  • Main body ECU (multiplex network body ECU)

  • Cowl side junction block LH

WIRING DIAGRAM

B001Z4OE12

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 (MAIN BODY ECU CAN BRANCH WIRE)


    1. B001Y5HE01
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Main Body ECU [Multiplex Network Body ECU])

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

    2. Disconnect the main body ECU (multiplex network body ECU) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E118-14 (CANH) - E118-13 (CANL) Cable disconnected from negative (-) battery terminal 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO MAIN BODY ECU (CANH, CANL)

    OK

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


    1. B001WOTE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Main Body ECU [Multiplex Network Body ECU])

      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. Remove the main body ECU (multiplex network body ECU) Click here.

    3. Reconnect the cowl side junction block LH connectors.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A-31 (BECU) - Body ground Always 11 to 14 V
      A-30 (ACC) - Body ground Ignition switch ACC 11 to 14 V
      A-32 (IG) - Body ground Ignition switch ON 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A-11 (GND1) - Body ground Always Below 1 Ω

    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

    NG

  3. CHECK HARNESS AND CONNECTOR (COWL SIDE JUNCTION BLOCK LH - BATTERY AND BODY GROUND)


    1. Disconnect the cowl side junction block LH connectors.

      B001X2SE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Cowl Side Junction Block LH)

      		 - -

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      2H-19 - Body ground Always 11 to 14 V
      2G-1 - Body ground Always 11 to 14 V
      2J-18 - Body ground Ignition switch ACC 11 to 14 V
      2I-18 - 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
      2J-1 - Body ground Always Below 1 Ω

    OK

    REPLACE COWL SIDE JUNCTION BLOCK LH Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR