CAN COMMUNICATION SYSTEM (for RHD) 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 one pair of CAN branch lines.

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 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 its CAN branch lines).

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

  • Skid control ECU assembly

  • Front steering control ECU*

  • Air conditioning amplifier assembly

  • Power steering ECU assembly

  • Network gateway ECU

  • Spiral with senosr cable sub-assembly (steering angle sensor)

  • Yaw rate sensor

  • ECM

  • Main body ECU (multiplex network body ECU)

  • Combination meter assembly

  • Center airbag sensor assembly

  • Parking brake ECU assembly

  • Multi-media module receiver assembly

  • Power management control ECU

INSPECTION PROCEDURE

Note


  • 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, 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.

  • 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: Allow the radar cruise control system (vehicle control mode) to operate for 1 second 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 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 "CAN Bus Check" Click here.

    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.


    NEXT

    GO TO CORRESPONDING COMMUNICATION STOP MODE Click here