Had another guy at the shop get a 98 2.0 Contour come in running poorly and barely stays running. Tech does a multitude of basic tests and finds the coil at fault and no spark on cylinders 2 and 3. Tech finds and fixes a few vacuum leaks and saves the coil for the next day. Ticket gets handed off and another tech throws a coil in but still has no spark on 2 and 3. So 2 more new coils later and still only spark on 2 cylinders. Tech replaces coil pigtail due to being a common issue yet no change. Known data is that tech verified power at coil and both ground triggers from PCM coil drivers us in a test light (outlined as test procedure per Identifix). At this point I hook up my DSO (Hantek brand Picco knockoff) and find dropouts in trigger waveform in suspect 2 wastespark cylinder trigger . I had a screenshot saved but unfortunately lost it. So to make absolute sure of the findings we switched the 2 and 3 trigger wires with 1 and 4 trigger wire and cranked car and spark moved to other 2 cylinders. Condemned 1 of 2 PCM coil driver failure due to coil shortage creating a voltage spike back through the driver in the PCM. But the biggest point being that it still showed signal on a test light. Hope this is able to help someone with the same issue.

Sean Mellon
Technician
Bobby and Steves Autoworld
Minneapolis, Minnesota, USA