CAN COMMUNICATION SYSTEM Bus Buffer ECU Communication Stop Mode

DESCRIPTION

Detection Item Symptom Trouble Area
Bus Buffer ECU Communication Stop Mode

Either 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 line or connector

  • CAN compatible optional device

WIRING DIAGRAM

B007300E05

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 engine 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 (-) battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.

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

    DTC check procedure: Turn the engine 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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  • Inspect the fuses for circuits related to this system before performing the following procedure.

Tech Tips


  • Before disconnecting related connectors for inspection, push in on each connector body to check that the connector is not loose or disconnected.

  • When a connector is disconnected, check that the terminals and connector body are not cracked, deformed or corroded.

PROCEDURE


  1. CHECK FOR OPEN IN CAN BUS LINES (OPTION CONNECTOR (BUS BUFFER ECU) BRANCH LINE)


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

    2. Disconnect the O97 option connector (bus buffer ECU).

      Tech Tips

      Disconnect any CAN compatible optional devices from the option connector.

    3. B0073SKC17
      *a

      Front view of wire harness connector

      (to Option Connector (Bus Buffer ECU))

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      O97-4 (CAN+) - O97-8 (CAN-) Cable disconnected from negative (-) battery terminal 54 to 69 Ω
      Result
      Result
      OK
      NG

    NG

    REPAIR OR REPLACE CAN BRANCH LINES OR CONNECTOR (OPTION CONNECTOR (BUS BUFFER ECU))

    OK

  2. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)


    1. B0073SKC18
      *a

      Front view of wire harness connector

      (to Option Connector (Bus Buffer ECU))

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      O97-7 (RGN1) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω

    2. Reconnect the cable to the negative (-) battery terminal.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      O97-1 (R+B) - Body ground Always 11 to 14 V
      Result
      Result
      OK
      NG

    OK

    REPAIR OR REPLACE CAN COMPATIBLE OPTIONAL DEVICE

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)