Check the DLC3

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

HINT: If your display shows UNABLE TO CONNECT TO VEHICLE when the cable of the hand-held tester is connected to DLC3, the ignition switch is turned to ON and the tester is operated, there is a problem on the vehicle side or tester side.
- If communication is normal when the tester is connected to another vehicle, inspect DLC3 on the original vehicle.
- If communication is still not possible when the tool is connected to another vehicle, the problem is probably in the tester itself, so consult the Service Department listed in the tester's instruction manual.