Several articles in Import Service have discussed the effectiveness of an oscilloscope as an automotive diagnostic tool. Many of you have already taken the initiative and are using an oscilloscope to ride the waves. But there are still some technicians who get thrown for a loop if they can’t find a sample or “known good” waveform for a particular circuit on a particular car. They feel they must have this information to determine whether the waveform traced on their scope is good or bad.