Check DLC3

Inspect the DLC3
The vehicle's ECM uses the ISO 9141-2 for communication.
The terminal arrangement of the DLC3 complies with the SAE J1962 and matches the ISO 9141-2 format.

Standard:

HINT: If the display shows "UNABLE TO CONNECT TO VEHICLE" when you have connected the cable of the hand-held tester to the DLC3, turned the ignition switch ON and operated the hand-held tester, there is a problem on the vehicle side or the tool side.

If the communication is normal when the tool is connected to other vehicle, inspect the DLC3 of the original vehicle.

If the communication is still impossible when the tool is connected to other vehicle, the problem is probably in the tool itself, so consult the Service Department listed in the tool's instruction manual.