Help with rough idle and code P0356

[goldengreenXLT]

Hi there, my name is Seb. I am new to this forum so thank you in advance for your patience and expertise in this matter. I hope I am posting in the correct sub forum as well.
* Background:
I recently purchased a used 2012 ford Explorer XLT 4WD with 115000 miles on it from a private seller. It appeared that the previous owner had done some kind of tune up on the SUV. It looked like coil packs, I am assuming spark plugs, were changed. The car ran fine for a little while and one morning, on my way to work I lost power and had to stop. finished the rest of the way at 10 MPH and back home the same way. Brought it to my local mechanic. He said the the coil pack on Cylinder 2 completely burnt out. In the process destroyed the PCM. He had no communication with the PCM after changing the coil. Took the car home and proceeded to purchase a used PCM and had it re-flashed. (I installed it myself and called locksmith for the flashing). ran ok but with a severe shaking in the engine around 1500 RPM. Above and below, it drove ok with a rough idle. I still have the problem as of now.
* What I have tried so far:
-reset the PCM. I bought For Scan and the OBD cable for my laptop. when the locksmith reset it I had a P160A code. no more code after reset.
-now I have a P0356 code (coil F primary/secondary circuit). purchased a Master craft coil, replaced it and still have the same code. removed new and reinstalled old one.
- tested both coil packs with meter and got same Ohm reading.
-tested all 4 VVT solenoids with meter and got the same Ohm reading, none of them appeared damaged.
-took apart and tested the evap. canister valve (blew in it to see if it was closed and not leaking) I think it's good.
-checked wiring harness visually and did "wiggle test", appears ok.
- took apart the air intake, clean plastics and filter. Filter was a little old and some oil was present in filter. looks like it's coming from the tube leading to the valve cover.
-with engine running tried all vacuum tube and breather tubes to air intake, appears to have no vacuum leaks.
- ran a full tank with Seafoam high mileage and injector cleaner.
-ran a full tank of premium gas.
* Questions:
- what is my next step?
-what other test can I do to trouble shoot?
-could I have a more serious vacuum leak?
I know it's a lot, but I wanted to be thorough. Thank you again.

 

[ProjectSHO89]

The P035x DTC indicates a circuit fault related to the #6 COP. It has to be either a faulty COP, a loose/poos connection, a wiring fault back to the PCM, or the PCM itself.

Nothing else will cause that fault code.

Include your engine identification so proper references can be looked up.

 

[goldengreenXLT]

Hi there. Thanks so much for your response.
Vin: 1FMHK8D87CGA95935
V6 3.5l 4WD
Trim: XLT
Note: the used PCM keeps coming back as a Ford Edge vvti when I plug it in to ForScan with a different VIN. Only the PCM. The rest is my VIN.

update:
I switched the coils around from 6 to 5 and I still have the same code coming up...

 

[peterk9]

Hi there. Thanks so much for your response.
Vin: 1FMHK8D87CGA95935
V6 3.5l 4WD
Trim: XLT
Note: the used PCM keeps coming back as a Ford Edge vvti when I plug it in to ForScan with a different VIN. Only the PCM. The rest is my VIN.

Welcome to the Forum.

Peter

 

[goldengreenXLT]

The P035x DTC indicates a circuit fault related to the #6 COP. It has to be either a faulty COP, a loose/poos connection, a wiring fault back to the PCM, or the PCM itself.

Nothing else will cause that fault code.

Include your engine identification so proper references can be looked up.

so it could be something in the wiring, you said. would it be worth changing the wiring harness or part of it?

 

[ProjectSHO89]

It would be worth TESTING the wire associated with the specific fault code for opens or shorts to ground or power.

Guessing is expensive.