CAN COMMUNICATION SYSTEM(w/o Central Gateway ECU) Open in One Side of CAN 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 of the lines in a CAN branch.

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 the lines in its CAN branch lines. In this case, the CAN branch lines 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 the lines in its CAN branch).

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 line is open, or output signals are incomplete.


  • Certification ECU (smart key ECU assembly)*1

  • Steering sensor (spiral cable with sensor sub-assembly)*2

  • Radio and display receiver assembly*3

  • Airbag sensor assembly

  • Power steering ECU assembly

  • Air conditioning amplifier assembly*4

  • Clearance warning ECU assembly*5

  • Engine stop and start ECU*6

  • Brake actuator assembly

  • Main body ECU (multiplex network body ECU)

  • Headlight leveling ECU assembly*7

  • Headlight swivel ECU assembly*8

  • Driving support ECU assembly*9

  • Pre-crash safety city sensor*10

  • Telematics transceiver*11

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 ignition switch to ON and wait at least 31 seconds, and then drive the vehicle at a speed of 20 km/h (12 mph) 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.

    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 V BUS BRANCH LINE


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

      Click here

    2. Using the GTS, select and perform the 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