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-   -   2014 GC Summit code P0302 Cyl Missfire (http://www.jeepgarage.org/f77/2014-gc-summit-code-p0302-cyl-missfire-66244.html)

mmoreda 10-03-2013 09:33 PM

2014 GC Summit code P0302 Cyl Missfire
 
Hey Guys,

Hopefully you may be able to help me out with this. I have a 2014 Grand Cherokee Summit with a 3.6l V6 engine that has 2,495 miles on it. I purchased it in May.

About a day ago the check engine/MIL light came on while I was stuck in a traffic jam. I live pretty close to work so most of my driving is in stop & go situations.

About two weeks ago I went to the dealership to get the GC flashed with the latest transmission and ECM versions since the Jeep was shifting in a rough manner. Needless to say, they performed the flashes yet I continue to experience rough shifting at lower speeds (in sport mode and regular mode both with & w/o ECO mode).

I'm not sure if the aforementioned had anything to do with it but just wanted to mention it in case it helps. Point is, I ran an OBC code scan and found two codes. Both of them were P0302 which indicates a misfire on the #2 cylinder. I've read several threads mentioning that this is pretty common on the 2012 MY WK2. In some cases engine head replacements were the only solution.

Being that I have yet to find information regarding this issue in 2014MY Grand Cherokees, I would very much appreciate your input regarding the subject. Should I erase the codes and see if they come back? Or should I take it to the dealership and have them figure it out? Given that the solution seems to be a head replacement which, as others have mentioned, may take anywhere from 2 to 7, I'd also like to know if it would be ok to get through the weekend and turn the car in on monday.

I very much appreciate your help with this issue and will keep you posted regarding any updates.

Thanks,
MM

AZhiCntry 10-03-2013 11:48 PM

Re: 2014 GC Summit code P0302 Cyl Missfire
 
Shouldn't be a problem to take it in on Monday but do take it in and have them document the codes and diagnose the problem.. It may not be a head problem at all.

mmoreda 10-04-2013 02:23 PM

Re: 2014 GC Summit code P0302 Cyl Missfire
 
So I ended up taking the Jeep to the dealer this morning. Just got a call from them telling me they had run the tests and that nothing showed up. Moreover, the tech mentioned in his report that the Check Engine Light was off when he turned on the vehicle. They will apparently give me a copy of the scan report when I go pick it up in about an hour.

What's crazy is that I not only found one but two P0302 codes when I did the OBD2 scan. I made sure not to erase them so that they could read them at the dealership. Also, I am completely certain that the Check Engine Light was on when I turned the Jeep in.

This sounds somewhat strange but I guess that with their advanced equipment they should have been able to spot a misfiring #2 cylinder. Nonetheless, since the service rep that took in the vehicle only wrote down "customer indicates CEL is on" instead of also including the fact that the customer mentioned a P0302 code, the technician most probably didn't even care to look into a live read of the motor in search of the misfires. I'll just wait until I get the report and make sure they write down on the "closing documents" that I pointed out the codes in hopes that if anything ever happens I can hold it against them.

AZhiCntry 10-04-2013 02:47 PM

Re: 2014 GC Summit code P0302 Cyl Missfire
 
Quote:

Originally Posted by mmoreda (Post 904158)
So I ended up taking the Jeep to the dealer this morning. Just got a call from them telling me they had run the tests and that nothing showed up. Moreover, the tech mentioned in his report that the Check Engine Light was off when he turned on the vehicle. They will apparently give me a copy of the scan report when I go pick it up in about an hour.

What's crazy is that I not only found one but two P0302 codes when I did the OBD2 scan. I made sure not to erase them so that they could read them at the dealership. Also, I am completely certain that the Check Engine Light was on when I turned the Jeep in.

This sounds somewhat strange but I guess that with their advanced equipment they should have been able to spot a misfiring #2 cylinder. Nonetheless, since the service rep that took in the vehicle only wrote down "customer indicates CEL is on" instead of also including the fact that the customer mentioned a P0302 code, the technician most probably didn't even care to look into a live read of the motor in search of the misfires. I'll just wait until I get the report and make sure they write down on the "closing documents" that I pointed out the codes in hopes that if anything ever happens I can hold it against them.

If you didn't erase the codes they would be there and they should be noted by the tech that they were there when they scanned/checked the veh. Make sure that they have the codes found noted on the final report!

mmoreda 11-20-2014 10:12 AM

Re: 2014 GC Summit code P0302 Cyl Missfire
 
Hey guys,

I just wanted to update this old post in order to add new information which may be useful to MY2014 JGC owners. After the previous saga certain events happened leading up to the replacement of the left cylinder head. During the period, my GC went to the dealer at least 6 more times due to a reappearing CEL. Out of those 6 times, 4 times the dealer just proceeded to erase the code. I had to actually change repair shops in order to see any progress.

Once I started visiting the second dealer, the issue was taken more seriously. Initially they swapped out the Power Control Module since apparently the vehicle was not only displaying a P0302 code but also an additional code (I don't exactly recollect at the moment which one). Needless to say, this did not fix the issue although it might have fixed another issue which I'm not quite aware of. After the PCM swap, the CEL turned on again. I returned to the dealer where they proceeded to erase it. I informed them that this was the sixth time I had taken the vehicle to the dealer with a P0302 code and they said to come back next time it turned on. As it turns out, the CEL turned on within a week of leaving the dealer.

This final time, the dealer finally put the vehicle through a series of tests and concluded that they had to replace the cylinder head. Had they listened to me from the start, everyone would have saved a ton of time. I actually had to threaten legal action in order to get them to repair the vehicle (no lemon laws in Puerto Rico, which makes this relatively hard to accomplish). I am supposed to pick-up the vehicle today and, if anything else regarding this issue occurs, I will update this post.

In essence, the reason i wanted to update this post is to provide additional details to MY2014 JGC owners with a similar issue. From everything I've been able to find, it seems that this issue is most prevalent in MY2011-2013 Pentastar V6 engines. However, it seems some 2014 engines exhibit the same problems.

If you're vehicle starts repeatedly displaying a P0302 code, I would strongly advise you to push your dealer to perform pressure tests on the #2 cylinder. Why? because they will likely go to extremes to work around the problem. It usually starts out with erasing the code, then they check the spark plugs and erase the code; afterwards they will switch around spark plugs and see if the problem persists, then they will proceed to change the coils. If the problem persists, they may do additional things such as changing the PCM. All in all, you may be looking at multiple visits to the dealership. I believe that, and please correct me if I'm wrong, a pressure test may expedite the process by ruling out any of the aforementioned "fixes".

Finally, I do hope that this never happens to any of you. I love my Jeep, and it really hasn't had any problems other than this. It's a shame that the dealerships and Chrysler haven't figured out a way to respond to this specific issue in a more efficient manner.

mmoreda 11-26-2014 12:04 PM

Re: 2014 GC Summit code P0302 Cyl Missfire
 
Well apparently I was overly optimistic regarding the delivery time of my vehicle. I have yet to receive it. I get little if any information from the dealer. It has now been 7 full business days since the dealer received the replacement cylinder head. I have seen many threads regarding Jeep cylinder head replacement which were done in much less time.

It's kind of crazy to think that the tech has had approximately 48-56 hours to work on this and has yet to finish. This brings up a couple of questions I'd hope the Jeep Garage community can answer. First, is it normal for the vehicle to spend that much time at the dealer for this repair? If not, what can possibly be taking them this long? Can it be that they weren't able to fix the problem? They found additional problems?

Any input from you guys is greatly appreciated. This has gotten to a point where I almost wish they're unable to fix this in order to proceed to try and legally cancel the purchase agreement, possibly swap the JGC for a new one (long shot, I know).


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