CAN COMMUNICATION SYSTEM(w/o 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 "CAN Bus Check" screen of the GTS 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 branch line or connector

  • Power source circuit of main body ECU

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

  • Main body ECU (Multiplex network body ECU)

WIRING DIAGRAM

A005D14E30
A005D14E35

CAUTION / NOTICE / HINT

Note


  • Before measuring the resistance of the CAN bus, turn the power 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 (-) auxiliary battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.

  • After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work Click here.

  • 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.

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

  • DTC check procedure: Turn the power switch on (IG) and wait at least 20 seconds.

  • 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 power 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 FOR OPEN IN CAN BUS LINES (MAIN BODY ECU BRANCH LINE)


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

    2. A005E2BE02
      Text in Illustration
      *a

      Front view of wire harness connector

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

      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
      L7-14 (CANH) - L7-13 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (MAIN BODY ECU)

    OK

  2. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)


    1. A005BOOE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Instrument Panel Junction Block Assembly)

      Disconnect the instrument panel junction block assembly connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      2B-6 (GND1) - Body ground Cable disconnected from negative (-) auxiliary battery terminal Below 1 Ω

    3. Connect the cable to the negative (-) auxiliary battery terminal.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      2C-18 (BECU) - Body ground Power switch off 11 to 14 V

    OK

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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)