So, I bought my escape used with 178k miles. So far, I'm not impressed. Everything was cool for a couple of days. Then it began intermittent misfiring. Throwing the codes P0352 and P0352 (Pending).

I knew all the plugs had recently been replaced (autolites). So, I bought a new COP and replaced it. No change. I took it to my mechanic yesterday and he said they had sold me a faulty COP, but had pressure tested and checked the injector which were all good. Told me the new COP had fixed it.

I drove it for about 5 miles, pulled into my parking lot and as I put it in reverse it began misfiring again. Same code. Remembering a fix that worked for one Escape owner, I disconnected the battery for a couple of hours. Reconnected and the misfire was gone. It did misfired (again when I put it in reverse) a short while later and I repeated my battery unplug and also disconnected the harnesses going to the PCM, inspected for damage or dirt, but didn't find any.

I've read the horror stories of replacing all coils, plugs, PCM and the problem still being there. I don't mind spending the money to fix it, but want to check all other possibilities before replacing PCM.

Does anybody here have any ideas or advice? Is it possible that my Crank Position Sensor is beginning to fail and causing this intermittent misfire? Or is it possibly some other sensor that I'm not thinking about?

Would this even be a problem if Ford used Mac for their PCM?

Any help will be VERY appreciated and I will update my posts in order to help others.

 

For years, Ford used the king of embedded processors, Motorola. The Mac used Motorola processors also.

But for everything else in your post, it would help others help you if you list your year and what engine you have.

 

Oh. Oops. It's a 2005 4 cyl. 2.3 L

Update: My wife drove it for around 12 miles today. Cranked it and turned off, used reverse and it hasn't come back...yet. I'd like to believe it magically went away, but realize its probably just a matter of time until it pops up again.

 

Get a new "mechanic" as this one doesn't seem to be up to speed.

P0352 is telling you that there is a fault in the cylinder 2 coil primary circuit. That runs from the PCM, through the harness, to the coil. It can also involve the power feed to the coil, which comes from the EEC relay. It has nothing to do with spark plugs or injectors.

You need to very carefully ohm out the related circuits. When you are absolutely positive the circuits are good (which is the cause of this code in virtually all cases,) then you are left with the PCM or the coil. Since you already replaced the coil twice, then that would leave only the PCM as suspect.

 

See TSB 10-18-10 for this vehicle.

 

In my mechanic's defense: He's a whiz with most vehicle repair, but maybe not in cases that require a degree in electronic engineering. I'll refrain from my rant about how sad it is that ANY car can misfire and have nothing to do with gas or spark.

I do appreciate this as the most helpful feedback that I've gotten. Just to clarify for my sake: Are you saying that it is more that likely a short in one or both of the wires that run to the COP? And if I replace both circuits, feel good about that repair and the problem persists, then the only thing left is that it's a problem in the PCM?

Thanks again.

 

Not a short but an open circuit. You prob have a wire that is broke but the insulation is holding it together and when the engine moves the 2 ends of the copper come apart causing the open circuit. With the engine running grab the harness and flex it back and forth to try to duplicate the open. Pay special attention to bends and places where the harness branches out. Ohming a wire will NOT tell you if its good because the broken ends could be touching by 1 strand and it will ohm good. You need to load test the wire with a test light. Once you find the break, cut open the harness and SOLDER and HEAT SHRINK a repair section. Crimp butt connectors will not last very long and you will get the same problem again.