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 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.

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


  • Hybrid vehicle control ECU

  • Main body ECU (Multiplex network body ECU)

  • Brake booster with master cylinder assembly (Skid control ECU)

  • Spiral cable with sensor sub-assembly (Steering angle sensor)

  • Air conditioning amplifier assembly

  • Power steering ECU assembly

  • Airbag ECU assembly

  • Transmission control ECU assembly

  • Certification ECU (Smart key ECU assembly)

  • Radio and display receiver assembly*

*: for Radio and Display Type

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 Click here.

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

    DTC check procedure: Turn the power 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 Click here.

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.

    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