CAN COMMUNICATION SYSTEM(for LHD) Open in One Side of Bus 3 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 wires are normal (there is no open, short, short to +B or short to GND in the main bus wires), there may be an open circuit in either of the wires 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 wires in its CAN branch. 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 the wires in its CAN branch).

Detection Item 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.


  • Multi-media module receiver assembly

  • Telematics transceiver*

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.

  • 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 (-) auxiliary battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.

  • After turning the power switch off, waiting time may be required before disconnecting the cable from the auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the auxiliary battery terminal notice before proceeding with work Click here.

  • 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.

  • 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.

Tech Tips


  • Operating the power 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 ONE SIDE OF BUS 3 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 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