Greetings! I recently sent a PCM for a 2006 Mercury Mariner and had it repaired. The initial problem was that it was throwing P0352, P0353, and P0355 codes and was misfiring badly. I've gotten the repaired PCM and have re-installed it but now I'm getting a P0354 code for the 4th cylinder. I've replaced all of the plugs and all of the coil packs. I've moved coil packs around and the problem persists as a P0354 error after clearing and starting the car again. The PCM was replaced in the car with the battery disconnected as recommended. Connectivity in the wiring harness has been traced and tested using a multimeter to look at continuity, looking for broken wires. None have been observed. Prior to the PCM being repaired, there was no P0354 error.
Suggestions for what I can do next?
Thanks for reaching out, please confirm if cylinders 2, 3, and 5 are now working properly. A coil pack swap with another is a good way to troubleshoot and it seems like you already did that. Please check the spark on the spark plug and the gap as well. If still having issues we can take another look under warranty. Call or email us so we can assist you further.