Before measuring the resistance of the CAN bus, turn the ignition 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.
After turning the ignition switch off, waiting time may be required before disconnecting the cable from the
negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative
(-) battery terminal notices before proceeding with work .
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
After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output
DTC check procedure: Turn the ignition switch to ON, wait at least 20 seconds 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 .
If the certification ECU (smart key ECU assembly) is replaced, refer to Registration
Operating the ignition switch, any other switches or a door triggers related ECU and sensor communication
on the CAN. This communication will cause the resistance value to change.
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.