CAN COMMUNICATION SYSTEM(w/ Central Gateway ECU) Bus Buffer ECU Communication Stop Mode

DESCRIPTION

Detection Item Symptom Trouble Area
Bus Buffer ECU Communication Stop Mode

Any of the following conditions are met:


  • "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 are output correspond to "Bus Buffer ECU Communication Stop Mode" in "DTC Combination Table"

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  • Bus buffer ECU CAN branch wire or connector

  • Bus buffer ECU

WIRING DIAGRAM

B001GTFE55
*a Dealer-installed Option
*b No. 5 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 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.

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  • DTC check procedure: Turn the ignition switch to ON, 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 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 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 (BUS BUFFER ECU CAN BRANCH WIRE)


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

    2. B001DCVC04
      *a

      Front view of wire harness connector

      (to Bus Buffer ECU)

      Disconnect the bus buffer ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G199-2 (CAN+) - G199-1 (CAN-) Cable disconnected from negative (-) battery terminal 54 to 69 Ω

    OK

    REPLACE BUS BUFFER ECU

    NG

    REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR