CAN COMMUNICATION SYSTEM Bus Buffer ECU Communication Stop Mode

DESCRIPTION

Detection Item Symptom Trouble Area
Bus Buffer ECU Communication Stop Mode

Any condition is met:


  • Communication stop for "Accessory Gateway" is indicated on the "Communication Bus Check" screen of the GTS.

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

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  • Option connector (bus buffer ECU) branch wire or connector

  • Option connector (bus buffer ECU)

WIRING DIAGRAM

B002JFQE68
*a Dealer-installed Option
*b No. 10 CAN Junction Connector
*c Option Connector (Bus Buffer ECU)

CAUTION / NOTICE / HINT

CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.

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.

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  • 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 or any 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.

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  • Some parts must be initialized and set when replacing or removing and installing parts.

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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 power switch on (IG) and wait for 1 minute or more. Then operate the suspected malfunctioning system and drive the vehicle at 60 km/h (37 mph) or more for 5 minutes 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 as normal.

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Tech Tips


  • Operating the power 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 OPTIONS


    1. Check whether dealer installed options that support CAN communication are installed.

      Result
      Result Proceed to
      Installed A
      Not installed B

    B

    CHECK FOR DTC Click here

    A

  2. CHECK FOR OPEN IN CAN BUS WIRE (OPTION CONNECTOR [BUS BUFFER ECU] BRANCH WIRE)


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

    2. B002JJKC06
      *a

      Front view of wire harness connector

      (to Option Connector [Bus Buffer ECU])

      Disconnect the option connector (bus buffer ECU).*

      *: When a dealer-installed option is installed

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I130-4 (CAN+) - I130-8 (CAN-) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω
      Result
      Proceed to
      OK
      NG

    OK

    CHECK DEALER-INSTALLED OPTION

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR

  3. CHECK FOR DTC


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

      *: When a dealer-installed option is installed

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Central Gateway / Utility / Initialization.


      Body Electrical > Central Gateway > Utility
      Tester Display
      Initialization

    5. Enter the following menus: Body Electrical / Main Body / Utility / Initialization.


      Body Electrical > Main Body > Utility
      Tester Display
      Initialization

    6. Enter the following menus: Body Electrical / Main Body / Clear DTCs.


      Body Electrical > Main Body > Clear DTCs

    7. Enter the following menus: Body Electrical / Main Body / Clear DTCs.


      Body Electrical > Main Body > Trouble Codes
      Result
      Result Proceed to
      DTC U1117 is not output from main body ECU (multiplex network body ECU) A
      DTC U1117 is output from main body ECU (multiplex network body ECU) B

    A

    END

    B

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) fro LHD: Click here
    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) fro RHD: Click here