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2017 Ram 2500 Megacab, Rambox, Factory air suspension, modified by adding factory fifth wheel prep
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Discussion Starter · #21 ·
Frustrating. Might also be a bad filter too. I don’t really have enough knowledge to offer any real advice, but agree really odd that it started after the service. Hard to believe it is just a coincidence.


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White Lightning
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Frustrating. Might also be a bad filter too. I don’t really have enough knowledge to offer any real advice, but agree really odd that it started after the service. Hard to believe it is just a coincidence.


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I know... Hopefully they can get it figured out.

Thanks again
 

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Use the last link in my signature to go to the page where you can make your own signature for your truck, with all the info, year, transmission, and any mods/add-ons, which makes it easier for us to help you.
 

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I hope i am asking this in the right place.
Ok so i have a 2012 Ram 2500 with the 6.7 Cummins and a 68RFE trans.
I had my MIL come on and it was throwing 2 codes P0087 and P0868. The only abnormal driving behavior was it would spike coolant temp and run for a few minutes with reduced power before returning to normal.
I took it to my local dealer and paid for a diagnostic. They told there was a bad coolant sender causing a false spike on the dash gauges. They said the P0087 was due to a leaking pressure limiting valve which needed replacement. Finally they told me my transmission was shot and needed to be replaced at a cost of $7500 for a reman trans installed. According to them when they dropped the pan they found excessive clutch material and "what appeared to be aluminum." The tech concluded that meant internal failure requiring replacement and wasn't worth trying to rebuild.
The total cost for repairs came to $11,000. When i scoffed at that the tech said they would button the trans back up and not charge me for the new filter or refilling it with fluid. Great guys huh?
Thoughts?
Is it likely that the trans is no good or should I take it to a trans shop for a rebuild attempt?
I do have a trusted mechanic that doesn't do trans work but will install a jasper trans for me for $5500. The other problems he can fix as well or I can for significantly less than the dealership so thats easy but the trans really concerns me. The truck has 145000 miles on it and only tows occasionally.
Appreciate any thoughts in advance!
 

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How often do you get the P0868 code? Do you notice any issues with the trans (weird shifting, slippage, etc.)?
P0868 is Line Pressure Low, so that is the transmission fault. I'm guessing P0087 must be a coolant temp sensor fault (judging from your description). Sounds like they got the codes mixed up, thought P0087 was the trans fault, and tried to blame it on the "leaking pressure limiting valve". I guess they must be referring to the T/C Limit valve (which indeed limits pressure to the torque converter when the TCC is unlocked), although that valve is inside the pump, so without pulling the trans and tearing it down, there's no way they could have looked at it. On top of that, I seriously doubt whether that valve would cause a P0868 fault even if it was "leaking".
I would just keep an eye on things for now. Low line pressure (lower than the target pressure) is not a big problem (on its own), unless the pressure falls so low that you start getting clutch slippage. If that happens, you'll start setting Gear Ratio Error faults like P0735 (which will also put the trans in "logical limp-in" where it starts off in 1st gear and then shifts directly to 4th and stays there until you come to a stop again. So operation is limited to 1st and 4th gears only (when in Drive; Reverse would still work OK). Since it sounds like you're NOT getting of these more serious symptoms, I would just drive it. See if you're only setting the P0868 under certain conditions (only when hot, only when in 4th, 5th, or 6th gear, etc.). That might provide a clue as to why the code is setting. Also, do you have a scan tool that can display Line Pressure and Desired Line Pressure? I'd be interested to see what those look like, and whether the actual line pressure is staying within a few psi of the Desired Line Pressure reading. If not, when does it happen, how low does the LP go, and how long does it stay there?
 

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Wow thanks so much for your answer. So the code P0087 is for low fuel rail pressure. I think the pressure limiting valve they are referring to in the paperwork is the fuel rail relief valve a lot of folks replace with those rail plugs. They are indicating the two problems fuel and and trans are unrelated. I did not see any codes for gear ratios or other trans issues. As far as weird driving behavior, when accelerating it would throw the code and feel like less power than normal. It seems to shift fine but i have noticed it not wanting to go into reverse when first started. Almost like its parked on a hill when its sitting on flat ground if that makes sense. This is very intermittent though.
 

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Yes sir they did. "Engine coolant temp sending unit faulty." And your correct, the coolant did not set a code, just affected the gauges. They said it wasn't actually running hot. No leaks or low coolant in the system. They seemed to indicate that they didnt think the faults were related. Basically they checked the codes, found the low line pressure trans fault and then dropped the pan and found metal, but i didn't see it and they didnt take a picture before cleaning it up.
 

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Also since it wasn't actually running hot, the reduced power on acceleration and feel of just not wanting to move right may be from the trans issue. I never felt any slipping in the trans but i don't push it much either. The sluggishness could be the beginning of slipping clutches I suppose. And i dont think i mentioned that its on 35 inch tires. No modifications to the driveline or gears. Deleted egr but otherwise pretty stock motor and not run hard at all. The heaviest I've towed was a boat at about 10k however, the previous owner pulled a 5er with cars.
 

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Again, if your clutches were slipping you should be getting Gear Ratio Error faults. Since that's not happening (and trans is not going into limp-in mode), I'd still say just continue to drive and monitor it.
 

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2017 Ram 2500 Megacab, Rambox, Factory air suspension, modified by adding factory fifth wheel prep
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Discussion Starter · #33 ·
So for a second time in a few months I got the P0868 code and again after a couple of days it cleared itself.

Like the other times this has happened there was no physical sign it happened other than the the Check Engine light coming on.

This time I was accelerating to pass at about 70 mph in northern Nevada after about 8 hours and 500 miles of driving that day and NOT towing or hauling.

I have now realized that the few times this has happened I tend to be at altitude and only after long days of driving.

I don’t know whether to ignore the issue or bring it into the dealer again so they can keep the truck for a long time and not diagnose it again. I worry a little that it might continue to get worse and the power train warranty may or may not cover it and my extended warranty may run out.

Again, the tranny acts fine and shifts great but that CEL scares me.

Does anybody have any thoughts on this?

@TransEngineer I still see you around from time to time and would really appreciate any thoughts you might have.

Thanks


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Sounds like the problem only happens when the trans is unusually warm (after long drive, at altitude, so I'm guessing you've been running a lot of uphill grades which will bring the temp up). This probably means you have some wear in the pump and/or valve body, which gives you some leakage of line pressure, which will naturally get worse when the trans is hot (and fluid is thinner). But yeah, if it only happens like once a month, at altitude, then the dealer won't be able to duplicate it, so they likely won't be able to address it. I would just continue to monitor it until it becomes more prevalent. Good news is that it's not bad enough to cause slippage in the trans, and it's not bad enough to be a problem at normal operating temp.
 

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I have been battling this issue as well. Only happens when towing the 5er. I live in Colorado and have had the light come on starting on a flat road outside of Alamosa . Most of the time though it happens low speed on hills though. First year took I took it to the dealer and they upgraded the software. Second year I didn’t have time to take it in also only happened once and cleared Third year dealer did valve body only. This year light comes on again on first trip. Like everyone else I would have no idea there is even an issue. Taking it to auto nation on Friday. Wonder if the pump is covered under the drivetrain warranty as the valve body was.
 

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Discussion Starter · #36 ·
Sounds like the problem only happens when the trans is unusually warm (after long drive, at altitude, so I'm guessing you've been running a lot of uphill grades which will bring the temp up). This probably means you have some wear in the pump and/or valve body, which gives you some leakage of line pressure, which will naturally get worse when the trans is hot (and fluid is thinner). But yeah, if it only happens like once a month, at altitude, then the dealer won't be able to duplicate it, so they likely won't be able to address it. I would just continue to monitor it until it becomes more prevalent. Good news is that it's not bad enough to cause slippage in the trans, and it's not bad enough to be a problem at normal operating temp.
Thanks for the response as always. Whenever I drive I always monitor temps on the EVIC and trans is almost always at 168. It only seems to increase when towing heavy at lower speeds and when ambient temps are hot which I assume is attributable to insufficient airflow. Once I gain speed the trans temps always drop to 168. Engine temps are a different story and will rise under load on a grade but drop right down when the fan engages or when I crest a hill.

The funny thing is the last few times this has happened I was not towing and was at speed with normal trans temps. But yes, it was after several hours of driving.

Not sure if you recall my history or if you saw my earlier posts that you gave me advice on but this trans has already had valve body and pump replaced and that seemed to work for a couple of years but this is now back apparently.

I think I will do my best not to worry about it and see if and when it happens again.

Thanks again.


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Got the check engine light and P0868 code for the first time last week pulling my 5er at about 8000 ft. There's a service bulletin on this now, at least for the 2018 RAM 2500. PCM needs to be flashed with an update. Worked for me, so far. Thanks Desert Sun Chrysler Dodge Jeep RAM in Alamogordo for getting me in and out in under an hour on short notice!
 

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Discussion Starter · #38 ·
That’s really interesting that your issue happened at high altitude too. Even more interesting to find out about the service bulletin. How do I find out of it applies to my 2017? I guess I can call the dealership tomorrow.

Thanks.


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Discussion Starter · #39 · (Edited)
Stopped by the dealer today and no bulletin on my 2017 2500. There was a flash required right after purchase in 2017 but nothing since then.


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