Primary Wiring Diagram 2001 Ford Windstar Ignition Coil Ignition coils are integral car components that resemble high-voltage transformers made up of two coils of wire. The first coil is called the primary coil, and the. P Ignition Coil C Primary/Secondary Circuit Malfunction. OBD-II Trouble Code Try wiggle testing the wiring at the #3 coil and along the wiring harness to the PCM. P0351 FORD Pcm Pin Out Diagram: Electrical Problem 6 Cyl Two Wheel Electrical problem 6 cyl Two Wheel Drive Automatic 92000 miles Where can I get a pcm connector pin out diagram for my 2001 Ford Escape 3.0. Looking for the Pcm Pinout Chart: I Have An Active Code When you get a good resistance reading, that coil of wire can't go up in resistance from what it was because that requires the piece of wire to become longer or thinner. Neither of those can change. The resistance would go down if many loops in the coil were shorted together, but that only occurs from excessive heat buildup in high-power coils, then the varnish insulation burns off the wires.