Code P0354 Circuit D Malfunction Solutions?

BigDaddyBabby

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01 V6 LS at 107k. Misfire on cylinder 4 throwing P0354 Primary Circuit D Malfunction. Seems to be a common issue as a search on here and Google yields many topics, but it seems no one returns to their threads to report what solved it, I assume they fix it and just don't report, or can't fix it and get rid of the LS.

Has anyone reading this experienced this and also solved it?

Quick background, car started running bad back in October. I did coils and plugs and am still having a misfire in cylinder 4. Swapped coil 4 to 5 and still missing on 4. it seems it could be a possibility of things such as not getting correct voltage to coil/injector, bad PCM, bad tensioner, etc.

I hope someone here has dealt with and solved this before I waste more money than I need to.

And on a side note, the misfire comes and goes. Sometimes it runs smooth, others I'm getting tossed back and forth in my seat while idling at a stop.

Thanks.
 
pretty sure it'll be traced back to a bad wiring harness/break in wire/corroded wire/high resistance OR a bad PCM. I'd just trace back the wiring to cyl. 4 and splice in a new wire to see if that'll solve the problem but that's just me since I'm comfortable doing so. If that doesn't work, pretty sure your PCM is toast from running on marginal/bad coils for a long time.
 
That's what I am thinking as well. Another concern of mine is I used cheap ass EBay coils back in October when I did them. Well the car has been siting and next week my mechanic is going to do OEM Motorcraft coils and new plugs, VC gasket, intake gaskets, and inspect injector 4 and wiring. Now, should I take it to the dealership before or after this work is done for a proper diagnostics?
 
That's what I am thinking as well. Another concern of mine is I used cheap ass EBay coils back in October when I did them. Well the car has been siting and next week my mechanic is going to do OEM Motorcraft coils and new plugs, VC gasket, intake gaskets, and inspect injector 4 and wiring. Now, should I take it to the dealership before or after this work is done for a proper diagnostics?

Before, in case the problem is a coil killing problem.
 
... it seems it could be a possibility of things such as not getting correct voltage to coil/injector, bad PCM, bad tensioner, etc....

If the code were P0304, you would be right. P0304 means misfire for cylinder 4. P0354 means that a fault in the primary wiring for coil 4 is detected. This causes the PCM to shut off cylinder 4.
As fudge12 says, it's going to be the wiring, the coil, or the PCM. It's possible that those money saving Ebay coils have cost you a PCM. It's also possible that you just have a broken wire or a defective connector.
 
It is also throwing p0304. Ok, so are we in agreement that I should take it to Ford before my maintenance work is done? Will they be able to tell me if its PCM, or wiring, etc?

Also this issue was evident before I did coils and plugs. I just thought that's what the issue was.
 
It is also throwing p0304. Ok, so are we in agreement that I should take it to Ford before my maintenance work is done? Will they be able to tell me if its PCM, or wiring, etc?

Also this issue was evident before I did coils and plugs. I just thought that's what the issue was.

Most likely, they will trace the wiring (if you are lucky they will actually do it) and say that it is the PCM if they don't find a problem in the wiring.
 
Oh wow. You think they'd actually trace my wires during a diagnostics? Isn't the intake in the way? I just want them to scan it and let me take it home. I don't want them doing the repairs. Too expensive for me.
 
"Scanning" it isn't going to accomplish any more than the two codes that you already have. To do correct diagnosis, they will have to charge you for whatever labor is required to trace the wiring. Removing the any of the intake would only happen if a wiring problem was found and you wanted them to fix it. "Tracing the wiring" will be unplugging coil 4 and the harness at the PCM. Test continuity between the negative coil pin and the correct pin on the PCM connector, and check continuity between the positive coil pin and the COP fuse. (Of course, they would also test for any current leakage to ground.)
 
I thought they could scan for leaks and unmetered air? Another possibility.

Not a possibility for code P0354. (You may have such problems, but you also (or only) have an electrical problem with the #4 ignition circuit. I would want to resolve the problem I knew I had before I went looking for other problems.)
 
Ok. So then it ultimately seems like I should do what I know needs to be done, PCV, PCV elbow, VC gaskets, intake gaskets, OEM coils and plugs, and see if that corrects my issue and go from there. My mechanic is going to check voltage at injectors and coils himself so I don't think I absolutely need to get it scanned at the dealership if my guy is going to do it himself.

If problem is untraceable and can't be fixed or found, then dealership.
 
This car cannot make up its mind. Car has been sitting for weeks. I get in it and turn the key, fires right up on all 6 cylinders. Nice smooth idle. But watch, I'll do this again tomorrow and it'll be rocking back and forth from misfire instantly. It seems if something is in dire need of being replaced then it would misfire all the time. Why just every now and then?!
 
This car cannot make up its mind. Car has been sitting for weeks. I get in it and turn the key, fires right up on all 6 cylinders. Nice smooth idle. But watch, I'll do this again tomorrow and it'll be rocking back and forth from misfire instantly. It seems if something is in dire need of being replaced then it would misfire all the time. Why just every now and then?!

What fuel are you using? How old is the fuel??
 
I have been running premium since I did coils in October, but up until then for a few months, I was running regular and mid grade at times. Yes, I know, big no no, and it won't ever happen again. I feel this may be a cause to my current issues as well. The mechanic originally said it seemed like water was in my tank, but I've since ran all premium and many bottles of HEET and still this issue.
 
I have been running premium since I did coils in October, but up until then for a few months, I was running regular and mid grade at times. Yes, I know, big no no, and it won't ever happen again. I feel this may be a cause to my current issues as well. The mechanic originally said it seemed like water was in my tank, but I've since ran all premium and many bottles of HEET and still this issue.


Running regular with bad coils may have done damage to the PCM; I believe, though may very well be wrong and invite a correction.


The OM for my new 535 not only "recommends" premium (it says super premium, AKI 89 or 91??), it says engine damage may result from running less than AKI 89/91. I have no idea the difference between AKI and octane......
 
there are a couple different ways that fuel octane is rated. AKI, or (r+m)/2 is how we do it in the USA.
so for Americans, AKI = fuel octane. europe for example, is different. they use RON i think.
 
Yeah that would make sense. I wonder if my misfire comes and goes because at some point in time after driving a bit, perhaps the PCM is shutting down cylinder 4 coil or injector. Maybe that's why today after sitting for weeks it fired right up.
 
There has been times, for example I was in a McDonald's drive thru, car was rocking, clearly missing, idle going from 500 to 900 rpms, bogging down, and it just kicked up to normal idle (800-900 rpms) and misfire gone. Grabbed my food and drove him misfire free.
 
Certainly sounds like a bad electrical connection or partially broken wire...
 
Certainly sounds like a bad electrical connection or partially broken wire...

FWIW I would agree. Had a few of those in my years; mainly the Christmas tree lights. I would double or even triple check the connector.
 

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