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missfire on a 2004 Chrysler pacifica


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Ok. So I'm banging my head on the concrete for this one.

 

I have a P0356 ("F" Primary/Secondary Ignition circuit) and P0355 ("E" Primary/Secondary Ignition circuit) codes being thrown on my chrysler.

 

Naturally, I replaced the spark plugs - installed NGK laser platinum (near OEM). and at one point it deliberatly said missfire on cyl 6. Now i only have those 2 codes. It has a coil on plug setup so i moved the #6 pack to #3 to see if the problem would move - It did not. I still have the same codes and it drives like bat crap.

 

The hardest part is GETTING to the spark plugs.. I have to take apart most of the intake to get to it..

420562_10152269115475727_671992737_n.jpg

 

Ideas? I'd hate to say it but i was thinking PCM :-/

 

-Justin

Edited by crazyman03
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I'm afraid I didnt get too far with that.. I ohmed the C.O.P.'s and noticed they were slightly different than each other.. 3 at .78 and 3 at .3ish..

 

I ended up taking it into a shop because the ECU IS in fact under warranty but one of their shops have to do the repair.

 

I dropped it off tuesday night, and after calling them today, they've apparently been banging their head on it too. They are thinking it to be some wiring gremlins.

 

Uugh, it was 50$ to diag. (which is a load of BS because all they did is hook a ODBII reader to it and verify what i already left in my "what is it doing" section) and another 65 for them to remove the "plenum" to get to the southern 3 coil packs. Which, to me, is crap because a "diagnosis of the problem" should be - "hey, here's the problem, and here's how to fix it." Not, "hey, I plugged my reader into your car and it says there's crap wrong.. you want me to look to see what crap is wrong?"

 

The sad part, is they are at the same place I was at before I dropped it off.

 

 

..... This is exactly why I do my own repairs. Just unfortunately, I was out of my league with books, knowledge and time to be able to completely diagnose this problem.

 

One part that kinda scares me a bit is - Here is Chrysler's "fix" for the P0306 and missfiring codes: http://www.aa1car.com/library/misfire_chrysler.htm Which is a code I did get at one point. Luckily, I havent gotten that one again after i put some (very concentrated) seafoam in the gas.

 

 

 

 

-Justin

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The ECU is probably seeing higher resistance on the wiring to the E and F ignition coils. (for cylinders 5 and 6)

I'd look into chewed/chaffed wires and poor connections, follow wiring back to any large junctions and disconnect, clean, and re-fit them.

Check and clean the contacts in the ECU connector as well.

 

 

Something I notice in the picture, How old is that alternator? Is it a Chrysler unit or reman?

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Something I notice in the picture, How old is that alternator? Is it a Chrysler unit or reman?

 

Probably OE---- OEM.. haha.. there's only 125k on it.. and as far as power, its running pretty strong. I did replace the battery with a larger one (closer to the right size mind you ) - simply because the battery that was in the car when i bought it was too small (about ~400CCA too small)

 

charging system is good.. and the battery is brand new. I did, briefly look at wires to see if there was any chafed wires but didnt find too much.

 

 

I am a little miffed about that.. I bought the car only 7 or 8 months ago at the most and if they think that I'm going to pay for (at least) half of this crap is BS. Its hard enough to make the monthly payment.. I'll just as soon as take the dam* car back and lump it in my bankruptcy.

 

In hindsight, I should've waited a bit like i wanted to and then bought the Subaru they had on the lot a week or so later - at least I would've been able to work on it, or, at least, had some input on how to work on it..

 

 

 

-Justin

Edited by crazyman03
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Well, I got news back from the shop.. it WAS the ECU/PCM. It IS under warranty, and through all the dinking around with the car, I only have to pay my 50$ "diagnosis" fee and not the other random BS that they tried to tack on just to diagnose it.

 

The guy also mentioned that the Injectors for cyl 5 and 6 were "missfiring" as well. Which, to me, what are the odds that the 2 coil packs and the injectors are missfiring?

 

Now, all I have to do is wait for the part to come in :-/. Hopefully it comes in today and it fixes the problem.

 

 

-Justin

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So.. I called the shop on Thursday, after i took the car back; after it took them a week to meter and trace wires and eventually (at first) find that it in fact was the PCM. Now they said that the problem is a Motor mount, is causing the wires to tug on the motor/frame and causing it to misfire?

 

Does this sound legit? on tuesday i drove the car practically all the way home without a problem about 7 miles. Up and down hills, stop lights (from 58th and Garrison to Golden (Map link this was my actual route )) and didnt have a problem, then suddenly it threw a CEL at a stop light just off of simms and 8th??

 

Am i crazy?

 

Any Input would be nice if you could. They are trying to stick me with a 250$ bill because the motor mount wasnt covered under the warranty and you know as much as I do how stinking easy (usually) to replace a mount. I call B.S. because I'm thinking the mount would've had to completly busted to cause the wires to tug because there should've been plenty of slack on the wires. Along with that, they should've found that problem a week and half ago when they were looking at the wires, tracing and such, and went "hey, this doesnt have a whole lot of slack"

 

sorry for the rant.. I'm just trying to get a prospective on it. I tried an actual chrysler forum but sadily, a subaru forum has replied to this topic (see here)

 

edit: I called Go Chrysler/Dodge's service dept. and the guy there even called B.S. on it. saying they are just throwing parts at it.

 

-Justin

Edited by crazyman03
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Motor mounts = BSing as they told you.

 

Ok, since I didn't read every post. The ECU was replaced, and probably not the issue. Did they check out the Coil pack/Igniter box (Or whatever this car uses for spark) Coil induction?

 

Are they sure its not a fuel delivery problem?

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Well, got the car back and the wife turned around and drove it back agian. :dead:

 

 

I figured as much since it was a motor mount they said was to fix the problem - though, i saw the old one and i already knew it needed replacing. I popped the hood to look at the wire harness and, of course, there's plenty of slack. The biggest problem i have is the shop is the "dealer" shop for warranties and they were the only one that did PCM/ECU troubleshooting.

 

Apparently, I P-O'd the shop because I called and ripped the guy a new one. eff this, eff that, get your effing car out of here... I did call back and apologize for doing that and worked the situation back down.

 

I got the car back home and looked at the harness a bit and got the C.E.L. to go away, somehow.. it worked its way out. I'm thinking something wasn't fully "clicked" in when they installed the new PCM.

 

 

edit: the new CEL was P0355 which is coil primary/secondary circuit for cyl 5. this is the same code I had (along with P0356 same code but for #6) when i took the car in in the first place

 

::facepalm::

 

-Justin

Edited by crazyman03
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Well.. I ripped that wire harness apart and found probably 7 or 8 wires that needed to be fixed.. I soldered and heat-shrunk them back new.

I did get a C.E.L. again though (P0355). Hopefully the other codes dont return since a couple of those wires should've fixed a couple codes, one was a signal wire to coil #6.. Here's hoping!

*prays to the car gods* *goes outside and provides a burnt offering*

 

A few pictures..

 

374932_10152323646090727_1658030465_n.jpg

598698_10152323784515727_190589438_n.jpg

 

 

-Justin

Edited by crazyman03
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I'll have to take a picture of where/how the harness comes from the block to the PCM...

 

Picture in your mind, the engine - Side to side with the crank on the passenger side (left), the harness comes from the #5 cyl on the right, moves towards the radiator ish, then strait down. meets with the front most motor mount, goes under it, then (inside the wheel well) goes up, and into the bumper. Why the bumper you ask? because the PCM is behind the fog light :-/

 

 

Chrysler-Pacifica_2004_800x600_wallpaper_08.jpg

yea, its behind the little reflector.

 

 

-Justin

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Those things are so gawdawful ugly.

 

Anyway...

So you're sure all connections are clean and tight (did you know they have pin testers to see how tight the grip is for these finicky plugs now?), you've swapped the E & F coils to other locations, and still have the codes after replacing the PCM?

 

Some googling says: http://www.permoveo.ltd.uk/tabid/122/OBD-Error-Code/P0355/Diagnostics/Chrysler/Default.aspx

 

Possible Solutions

 

Is the engine misfiring presently? If not, the problem is likely intermittent. Try wiggle testing the wiring at the #3 coil and along the wiring harness to the PCM. If manipulating the wiring causes the misfire to surface, repair the wiring problem. Check for poor connection at the coil connector. Verify the harness isn't misrouted or chafing on anything. Repair as necessary If the engine is misfiring presently, stop the engine and disconnect the #3 coil wiring connector. Then start the engine and check for a driver signal to the #3 coil. Using a scope will give you a visual pattern to observe, but since most people don't have access to one there's an easier way. Use a Voltmeter in AC Hertz scale and see if there's a Hz reading of between 5 and 20 or so that indicates the driver is working. If there is a Hertz signal, then replace the #3 ignition coil. It's likely bad. If you don't detect any frequency signal from the PCM on the ignition coil driver circuit indicating the PCM is grounding/ungrounding the circuit (or there is no visible pattern on the scope if you have one) then leave the coil disconnected and check for DC voltage on the driver circuit at the ignition coil connector. If there is any significant voltage on that wire then there is a short to voltage somewhere. Find the short and repair it. If there is no voltage on the driver circuit, then turn the ignition off. Disconnect the PCM connector and check the continuity of the driver between the PCM and the coil. If there is no continuity repair the open or short to ground in the circuit. If continuity is present, then check for resistance between ground and the ignition coil connector. There should be infinite resistance. If there isn't, repair the short to ground in the coil driver circuit NOTE: If the ignition coil driver signal wire is not open or shorted to voltage or ground and there is no trigger signal to the coil then suspect a faulty PCM coil driver. Also keep in mind that if the PCM driver is at fault, there may be a wiring problem that caused the PCM failure. It's a good idea to do the above check after PCM replacement to verify there won't be a repeat failure. If you find that the engine isn't misfiring, the coil is being triggered properly but P0353 is continually being reset, there is the possibility that the PCM coil monitoring system may be faulty.

 

Which sounds like pretty sound diagnostic advice IMO. Only issue being you may want a wire diagram or PCM I/O pinout. And you definitely want to check this with a High Impedence DIGITAL meter if you decide to try the DVOM method. Computers don't like analog meters for the most part.

 

Much more helpful than the Schysler forum.

http://www.chryslerforum.com/forum/chrysler-pacifica-15/p0305-code-p0355-code-2004-pacifica-14116/

 

Hopefully his name is not an indicator of occupation, "Chrysler Tech" says code P0355 doesn't exist.

 

I do still suspect that alternator as they can cause some crazy wacky issues, especially with that kind of mileage it may be beginning to go bad. You might try checking for AC ripple on the output lead.

 

Problems like this kinda remind me of the RF interference problems Lincoln had on the 04-06 LS. If one of the coil packs near the electronic throttle body went bad It would screw with the data signal sent out by the ECU and would confuse the ECU. It would set a code for the throttle body and go into Limp mode. Very strange occurance. Not sure how often it happens now since they had a campaign to replace the COPs on all of them.

 

:lol: :lol: I just read the thread you linked to! Too funny! :lol: :lol:

Edited by Fairtax4me
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Welp, pulled the harness out.. I went through every stinking wire on it and there arent any more breaks. Put it back in and got a p0355 - coil #5 error. for some odd reason I thought to put one of my original spark plugs in and the problem went away..........

 

....away to cyl 6.

 

I thought, well crap.. switch the spark plugs back to "OEM" which are champion double platinum. (which are GREAT lawn mower spark plugs).. problem stayed at #6.

 

 

I drove the car to another shop to see if they'd look at it. if this shop cant fix it, I'm taking it back to the dealer.

 

which brings me to my next topic. Anyone know of any cheap late 80's early 90's GL's? or maybe a 94ish impy?

 

 

pictures:

545501_10152345958170727_1676751569_n.jpg

 

 

 

-Justin

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Sounds like a fuster-cluck. Is there any other module that controls ignition on that car? Or do the coil wires go straight back to the PCM?

 

Seems odd for a spark plug to affect a coil pack issue. I honestly don't see how that's connected.

Are the wires to the coils shielded?

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no.. not shielded. I took it to another shop to diagnose it back to a PCM problem. they agreed and now I'm taking it back to the first shop to get it warrantied.. hopefully it fixes the problem, otherwise I'm taking the car back to the dealer :-/

 

 

-Justin

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Uuh.

 

1), I. Am. Never. Buying. A-car from. Drive time ever again!

 

 

2) ........ Or another Chrysler..

 

 

 

 

That aside. Drive time now wants the shop, the same shop that I had it at originally, to do everything they did the first time again before they'll warranty the pcm again. 250 out of pocket potentially.. Ugh..

 

 

-Justin

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Update,

Well, I re-inspected the wires and found nothing new. I even replaced the spark plugs to the "OEM" champion double plat.'s nothing new; even pulled the entire harness out to check...

545501_10152345958170727_1676751569_n.jpg

 

 

Took it to another shop, varified that the PCM is bad again. and ended up taking it back to the origional shop and had the PCM warrantied.

 

 

Well. Picked the car up last night - So far, so good. they replace the PCM again..

 

557573_10152359987225727_2033349764_n.jpg

 

aparently, they got a hellova deal on the PCM

 

I also decided to clean the inside. it pisses me off but, still such a slick car423092_10152361448030727_1664897573_n.jpg

 

542978_10152361916055727_1707632250_n.jpg

 

 

Next on the agenda, getting a drop down LCD for the back seat. I found how to splice into the video out of the 6disc changer to do video.. might do some creative splooging there..

 

 

-Justin

Edited by crazyman03
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