Hey everybody, I've used this sub a lot since getting my Ram but this is my first time posting. I'm in a real pickle and would love some advice on how to try and fix this issue. Buckle up, it's a long story.

So, I recently bought my 2010 Ram 1500 from my uncle in-law. He had a stoke a few years back and isn't supposed to drive anymore. So, the truck had been sitting for probably about 2 years (not great, I know). He said he would sometimes take it for a spin around the block against the doctors orders and would sometimes run it just because he liked to hear the exhaust. Otherwise he had always taken really good care of it. But everything hit the fan once I became the owner...

Chapter 1: The cliche "everything is perfect.. maybe too perfect" introduction

I drove it 4 hours from VA from the uncle's to NC where I live and it needed an alignment but otherwise ran like a kitten. Then, my wife and some friends wanted to surprise me for my birthday with a weekend cabin in the mountains. Sounds great, lets take the truck! This was when I realized the truck was only 2wd. The uncle gave us such a good deal that I just said yes immediately without getting all the details. Anyways, there was a steep hill that the truck struggled to get up. I had to get a running start and she spun some and I certainly had the rpm's higher than they had been in years (not enough to make me concerned about causing damage, but still). We make it to the top and the check engine light pops on. @#$%. I get out and check the engine and the truck cuts off. Won't start up. Middle of scenic nowhere. Happy birthday! Anyways, I left the truck where it was and came back the next morning. Still wouldn't start. So I checked all the fuses and the ASD (auto shut down) fuse was blown. I swapped it out with the windshield wiper fuse and it fired right up. I turned around and started to take it straight home. Shortly after the engine light flashed at me so I stopped. I was getting a misfire code for cylinder 7 and an ignition coil code. So I thought, "great, I'll get a new coil and swap it out." I did just that and nothing changed. Thinking the new coil may possibly be bad, I moved it to cylinder 3. The misfire followed it BUT I still had a misfire on #7, which now had the old #3 coil on it which previously didn't have any issues. So now I have two misfires. Lots of YouTube later I felt like the issue might be the PCM. Other people had very similar issues. My theory was that something was fried in the PCM which then ended up frying the coil #7. So when I moved it, the coil was already done for. And when I put a working one in, it just fried it right away too.

Chapter 2: The Curse
I called Dodge to see about getting a new PCM. I tend to avoid getting things from the dealer because I'm poor but this seemed like something that might be worth having the proper part for. Gave them a call. Turns out computer chips are still hard to find and apparently there is a strike going on so the part is on backorder until who knows when. Great. I guess I'll try something else. So, I found a shop on Ebay that repairs PCMs. I talked with them and they said they have seen the same issue before with Dodge. It was $200 some bucks so I figured why not. Packaged it up and sent it off with UPS. A few days later I checked in with the shop to see when I could expect the part back. They didn't have it.. Turns out UPS lost the package. Awesome! But it's ok, they gave me $100 for my troubles. Good thing a new PCM is $1500 and not available anyways, so that works out nicely. Now I have no PCM.

I ended up finding a shop that takes a used PCM out of a similar vehicle and reprograms it to fit your vehicle. I was a little skeptical but didn't really have any other option. So I bought one for $500. Just to be safe I got all new coils and plugs and swapped them out first. Didn't want a bad coil to fry my new PCM. Then I got the new PCM which was not lost in the mail (brownie points for FedEx). I put it in, fired the truck up, and @#$% yeah! It worked! I let the truck run for about 20 mins in my driveway just to see if everything was actually working. Ran and sounded great the whole time. The next step was to take a short test drive. I was overdue on my usual visit to the dump to drop off our trash so that seemed like a good test drive. It's less than 10 minutes away. So I load up the trash and hit the road. Once I get the the dump the check engine light flashes. You can image how excited I was! I could tell the engine started misfiring. As soon as I got it up the dumpsters, it cut off. Just like the first time in the mountains. Very upset but also slightly amused at the irony of my luck that I actually broke down at the dump, I thought "well, that's ok at least I know I can swap out the ASD fuse and take it back home." Nope. I guess there's something to do with the heat that made the ASD fuse blow immediately when I swapped it out on a hot engine. Four more times in fact! Fortunately (sarcasm again in case you haven't noticed a theme), the dump was about to close and all the old ladies throwing away their garbage asking if I needed help were very nice. I ended up having to call the tow truck. The dump people were nice and kept the place open late so the truck could get in. So, Benji (my mini aussie pup that I should not have brought) and I had to wait alone at the dump for over an hour. The tow truck driver was also very nice and happened to live pretty close to me. Anyways, add another $100 to my ongoing money pit. The check engine code was the same as before, misfire and bad coil in cylinder #7. After closer inspection, the brand new coil pack in cylinder #7 had melted a little bit..

At this point, I'm really struggling to find humor in the situation. So, I call Dodge and set up a diagnostics test. I felt sure I'd be able to drive the truck once it cooled down like last time on the mountains. I was right. Still misfiring and beeping at me regularly on my way to the dealership, but she made it. So I sit at Dodge for 3 hours waiting for them to make all my troubles disappear by telling me exactly what I needed to fix. The tech comes in and says "you've got a bad PCM." Who would've thought! Add another $200 for the diagnostics. He said he checked everything else and didn't see any issues other than the PCM. Wires are all fine, etc. Since the part isn't available anyways, he sent me on my way with my broken truck. He actually recommended getting a used one reprogrammed. Wish I had thought of that! Oh wait.. It was refreshing to have a dealership actually recommend such a thing though.

So this got me wondering.. The used PCM I got worked for a little while. Is there something in the truck causing the PCM to fry? Or is it a very strange coincidence that the same exact thing would happen? Same cylinder and everything? I really don't want to buy another one just to have it fry on me too. But, I'm not sure what else to do at this point.

So thus concludes the book on the unfortunate adventures of my life the past month and a half. So, having nowhere left to turn, I'm hoping that a Gandalf/Dumbledoor/insert other wizard name of Dodge issues can come to my rescue before I no longer have hair left. Does anyone have any thoughts? I am beyond stumped.

Things I did:
- checked the cam sensor (fine)
- changed all coils and plugs
- tested for power between PCM and coils (all were getting power)
- test for control between PCM and coils (#7 was the only one not getting control. #3 also lost control when I moved the #7 to #3, while #7 cylinder still also had no control).
- there's more but I cant remember it all after writing this book

Other random note: There are aftermarket LED headlights in the truck. The left light started to flicker some before any of these issues started. It still does it and the right started doing it too. I can't think of any correlations unless something is shorting out back to the PCM and frying it?

Truck Info: 2010 Ram 1500 2wd SLT Quad Cab 5.7 Hemi.

Help me Dodge Forum, you are my only hope.
Greg

 

Do you know if the tech at the dealership connected an oscilloscope to the #7 coil trigger to confirm whether or not it's getting a good trigger? I'd struggle to condemn a PCM without confirming whether or not there is a good signal to both the #7 coil and fuel injector.

Also, at any time did you confirm the coil that was on #3 originally was bad after you moved it to cylinder #7? If the fuel injector on cylinder #7 is actually the problem, or there is some mechanical issue with the cylinder, putting a good coil on that cylinder is still going to have a misfire but would not necessarily damage the coil.

I'd also suggest you take a careful look at the connector to the coil and fuel injector for cylinder #7, especially since you mentioned the coil looked slightly melted (assuming you were referring to the connector). There's not much I can think of that would enable a bad coil or other cylinder issue to cause damage to the coil driver transistor in the the PCM (especially 2 PCMs) unless there is an intermittent connection that is causing the current draw in the circuit to spike, or some other wiring issue that allows too much current to flow through the driver transistor.

-Rod

 

Hey Rod, thanks for helping out!


Do you know if the tech at the dealership connected an oscilloscope to the #7 coil trigger to confirm whether or not it's getting a good trigger? I'd struggle to condemn a PCM without confirming whether or not there is a good signal to both the #7 coil and fuel injector.
I'll admit I'm not great with electrical issues so bear with me.. I'm not sure if the tech used an oscilloscope on coil #7. He did say that he checked the connection/wiring between the coil and the PCM and it ultimately led back to the PCM as being the issue. That said, when they initially came and told me it was the PCM I asked if they were sure and questioned if they found any issue with the coil #7 (which the top portion that gets bolted on and holds both the boots was melted (see pics), so I was surprised they didn't find any issue with it). They went back "to check" and came back another hour later saying it was definately the PCM.

Before taking it to the dealer I tried to check this myself. I back probed the coil wire connectors and used a test light. When I connected the light to the positive and negative terminals of the battery (don't remember in which order) I was able to see that all the coils were getting power (the test light lit up bright and stayed on). But, when I switched terminals on the battery all but coil #7 gave a dim pulsing light, which according to youtube was showing that coil #7 was not getting control from the PCM. I don't know if there could be other reasons for this happening. I just don't know enough about this stuff. My memory is failing me a little but I think I tried the same thing for the injectors and all had power and all had control.

Also, at any time did you confirm the coil that was on #3 originally was bad after you moved it to cylinder #7? If the fuel injector on cylinder #7 is actually the problem, or there is some mechanical issue with the cylinder, putting a good coil on that cylinder is still going to have a misfire but would not necessarily damage the coil.
I believe I took the #3 and put it on #7 and after it didn't work I put it back but the misfire followed it so I assumed that anything I put on coil #7 was going to ruin the coil. I also put all knew coils on with the new PCM and coil #7 melted.

I'd also suggest you take a careful look at the connector to the coil and fuel injector for cylinder #7, especially since you mentioned the coil looked slightly melted (assuming you were referring to the connector). There's not much I can think of that would enable a bad coil or other cylinder issue to cause damage to the coil driver transistor in the the PCM (especially 2 PCMs) unless there is an intermittent connection that is causing the current draw in the circuit to spike, or some other wiring issue that allows too much current to flow through the driver transistor.
I did look at all the wire connectors that connect to the coils and injectors. I didn't see any visual issues that would lead me to believe there was a problem. The dodge tech also said all the wiring was good. Not sure how in depth they look though. That's really why I ended up taking it to them because I don't know enough about electrical stuff and hoped they could at least rule some things out. What might cause an intermittent connection that leads to a spike? Someone else I talked to said something similar and felt like there had to be a short circuit somewhere. I just don't have any idea where to look and with dodge telling me all the wiring was fine, I'm even more stumped...

Thanks again for your help on this. I really do appreciate it.

 

I think you failed to upload the picture of the melted coil.

The fuel injectors and ignition coils have battery power via the ASD relay and the PCM controls the ground to the injector / ignition coil. If you used an LED test light the method would provide a good indication. I personally wouldn't have used a standard incandescent test light for fear of loading the circuit and because it would not necessarily be able to flash fast enough for the pulses, but whatever you used sounds like it worked well enough in your situation to indicate something is different with cylinder #7. What it wouldn't tell you is if the wire is good all the way between the PCM and the coil, but the dealership claims to have done that.

If the dealership did everything they said they did and you've had multiple PCMs that ended with similar symptoms, this is a stumper....

-Rod

 

Oops, yep here's the pics!

This is the brand new coil on the #7 cylinder. Ran for less than 10 miles and then melted. This was after I got stuck at the dump.

This is another one that is not melted for reference.

 

Yeah the test light I used was incandescent but I could see it pulsing and it was the exact same for all the coils except #7 which had no light whatsoever. I was really hoping Dodge was going to say there was a wiring issue so I was surprised when they said it all looked good.. It took them 3 hours to check everything so I'd like to think they were thorough but I guess you never know unless you can watch over them.

 

Havi g a similar issue

 

I'll give an update for anyone dealing with something similar.

Took it back to dodge. Wrote them a very detailed letter stating that I knew the PCM was bad but that there was some other root cause making the PCM go bad, and that it would just happen again if a new PCM was put in. Took them 3 weeks to look at it. They originally thought it might be the camshaft. After their master tech looked at it, he determined it was a short circuit in the wiring harness which was causing the PCM and ignition coil to short out beyond repair. They don't make the wiring harness anymore so going used is the only option. Dodge apparently had sourced one but when I checked it was not actually compatible with my truck.. Not sure where to source one now other than scouring the junkyard listings. The PCMs are shockingly back in stock, but considering I've had success with used ones at 1/3rd the price, I will not be going new. To fix the PCM and wiring harness, Dodge quoted $5,500. I said no thank you! They also tried getting me to pay for the PCM I got put on a waitlist for 5 months ago since it finally became available.. After a lengthy argument, I did not pay for it.

I can do the PCM myself ($500) and I found a shop that is willing to change the harness out (estimated around $1500 - 11+ hours of labor). They're going to take a look and see if the short is fixable before replacing the entire harness. Because Dodge further jacked up my PCM when diagnosing it, it no longer drives at all and now I have to have it towed. Thanks for everything Dodge! BTW, when I went to pick the truck up and drive it home after the diagnosis, Dodge let me pay, sent me out the door, said have a good day and said bye. Like I just mentioned, the truck doesn't drive now (I drove it to the dealer). So I had to go back in and tell them at which point they said "yeah, its not drivable anymore without a new PCM". So they sent me out there knowing full well the truck wasn't going to start. As you can imagine, that didn't sit too well with me.

Dodge has been a nightmare to deal with throughout the whole process. Not that anyone probably needs to hear this but, avoid the dealerships if you can...

Hopefully this shop can find the short and fix it. We'll see.