For Using Hand-Held Tester Or OBD II Scan Tool

Before using the tester, read its user manual thoroughly.
Connect the cable of the tester to DLC3, turn the ignition switch ON and operate the tester. If the tester cannot communicate with the ECU controlled system, there is a problem on the vehicle side or tester side.
1. If communication is normal when the tester is connected to another vehicle, inspect the diagnosis data link line (Bus (+) line) or ECU power circuit of the vehicle.
2. If communication is still not possible when the tester is connected to another vehicle, the problem lies in the tester. Perform the Self Test procedures outlined in the Tester Operator's Manual.