CAN COMMUNICATION SYSTEM(for LHD) Open in One Side of Bus 4 Branch Line

DESCRIPTION

If an ECU or sensor is not displayed on the "CAN Bus Check" screen of the GTS and some ECUs and sensors repeatedly appear and disappear from the screen when the CAN main bus lines are normal (there is no open, short, short to +B or short to GND in the main bus lines), there may be an open circuit in either wire of one pair of CAN branch wires.

Tech Tips

If some ECUs and sensors repeatedly appear and disappear from the "CAN Bus Check" screen, communication between the normal ECUs (sensors) and the GTS may be affected by the incomplete signals that are output from the ECU that has an open circuit in either of its CAN branch wires. In this case, the CAN branch wires for the ECUs and sensors that repeatedly appear and disappear from the screen are normal and the ECU that is not displayed on the screen may be the main cause of the problem (this ECU may have an open circuit in either of its CAN branch wires).

Symptom Trouble Area
2 or more ECUs and/or sensors do not appear on the GTS "CAN Bus Check" screen.

One side of CAN branch wire is open, or output signals are incomplete.


  • Brake actuator assembly (skid control ECU)

  • Roll rate and vertical acceleration sensor (yaw rate sensor)

  • Driving support ECU assembly*1

  • Torque vectoring differential ECU assembly

CAUTION / NOTICE / HINT

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.

    Click here

  • 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), wait at least 60 seconds, and then drive the vehicle at a speed of 40 km/h (25 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.

    Click here

Tech Tips

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 ONE SIDE OF BUS 4 CAN BRANCH WIRE


    1. Based on the vehicle equipment and specifications, confirm the systems that use CAN communication.

      Click here

    2. Using the GTS, select and perform "CAN Bus Check"

      Click here


      CAN Bus Check

    3. Observe the screen for approximately 2 minutes to check the ECUs and sensors that are not displayed on the screen and also those that repeatedly appear and disappear from the screen.

    4. Check the applicable communication stop mode for the ECU or sensor that is not displayed on the screen.

      Result
      Proceed to
      NEXT

    NEXT

    GO TO CORRESPONDING COMMUNICATION STOP MODE Click here