P0871 not valve body

[kjg26]

I've posted about this issue before but it is still unresolved. I have code p0871. 2016 ram 2500 with 68RE transmission. The valve body has been replaced twice now with the solenoid pack and everything else. Internal the transmission looks spotless. I'm told it could now be a PCM or wiring issue. Where would I start tracking the wires? Troubleshooting PCM issue?

 

[HEMIMANN]

Trans. issues and P0871

www.cumminsforum.com

Did they replace the valve body block? Sounds like an issue with the main plunger being in the wrong position - so could be the bore or plunger concentricity or actuator / wiring.

"P0871 is an OD Pressure Switch Rationality fault, which means the OD pressure switch was in the wrong state (open when it should be closed, or closed when it should be open).

How many miles on your truck? If 90K+, then you likely have a worn solenoid switch valve (SSV) bore in the main valve body. This is fairly common at high mileage, and allows fluid to leak into (or out of) the OD clutch circuit. First sign is usually this fault code. Fix would be to replace the entire VB assy (not just the solenoid) with a new Mopar valve body. Part number is RL033980AC and list price is $463. The new service VBs are all anodized to resist this wear. The Mopar part number is a "reman" number (so they can get your old VB back for core), but the parts are actually brand new assys, not reman.

There are other things that can cause the P0871 fault (like a bad wiring connection), but if you're at high mileage I'd recommend replacing the VB assy. That is likely the problem."

 

[kjg26]

The valve body assy has been replaced, twice now. The problem is intermittent and seems to be no rhyme or reason as to when it decides to toss the code. This time I was accelerating from a stop light without any load on the truck.

 

[kjg26]

Truck has 206k miles on it. Has had an easy life as far as these trucks go.

 

[Burla]

Was this the original code as well, before they others were replaced? Did you replace VB or did a mechanic? Did the Vb's end this for a while? This issue comes from the VB, I don't know what else to say. Your saying the code showed up in early gears from a stop sign, like 1,2 or 3rd?

 

[kjg26]

Same code has been there. P0871. Lost OD. Then to mechanic. He replaced the valve body. Relearned the trans. Drove fine for 1 week. Kicked same code. Lost OD. It reset itself after sitting for 12 hours while I was at work. Drove home. No issues. Mechanic couldn't find any issues. Kicked again and would high Rev and hard shift up to 4th gear. Wouldn't go into 5th or 6th. Replaced with another valve body. Relearned trans. No issues for 4 days. Just Kicked it again. Hard shifting and don't have 5th or 6th. It seems to reset itself after sitting for a while and then drives fine.

 

[kjg26]

Today when it kicked the code again I was maybe doing 25 mph and coming off a light.

 

[yoda]

Check for spread terminals on that circuit at the solonoid and PCM first.
Hard to do without a pin fitment gauge.

If ok, Not an easy task, but if you could get a hold of a wiring diagram, swap the O.D pressure switch circuit with another pressure switch circuit at the solonoid pack and at the PCM, actually pull pins out of connectors is the best, then you eliminate a possible pin fitment issue also.

If the same DTC resets its not a wiring issue. PCM is defective or Since valve body has been replaced twice your getting cross leakage somewhere internally in the Trans. (rare and not easy to find) you may want to go with a trans assembly

If it sets a DTC for the circuit you swapped it to, its a wiring issue in that circuit.

 

[kjg26]

Where is the PCM located? Also where is the wiring harness for the solenoid on the transmission?

 

[yoda]

The PCM is bolted to the drivers side of the Engine Block.
The Wiring plug for the transmission is on the drivers side of the trans.

 

[ZombiePanda]

I know this is an old thread. My 2018 Ram 2500 with the 68RFE has very similar symptoms as OP. Something mine is doing (or rather not doing) that OP didn't mention is my +/- buttons on my shifter do absolutely nothing. They just don't work. Other than that, my symptoms are almost exactly the same as OP. Local shop wants $10k to replace the entire transmission. I haven't tried to replace the valvebody yet. I'm trying to determine if the valvebody is the issue before spending money on it. If the problem is indeed inside the trans, then that $1500 is just wasted. @yoda you mentioned a pin fitment gauge. Any idea where I could get one?

This is my first diesel truck, and I mostly daily drive it with occasional towing. Definitely not into max HP/TQ. I bought the truck T&D'd but leave the switch in the #1 position.

 

[Boltrounder]

I’ve just dealt with this maddening issue with my 2007 Ram 1500 4.7L 2WD 545FRE at 186,000 miles. Threw a P0871 code repeatedly, even AFTER new trans AND new OEM valve body & solenoid… Suspecting a wiring problem, they went hunting (for 3 days) and found a short in the wiring harness, according to the mechanic. I’ll find out exactly where and which wire in the morning when I pick it up, and I’ll pass along the details then… I hope this helps some folks a bit of time, a LOT of hassle, and especially the cost ($6000 for me!!)…
I’ll follow up in the morning…

 

[Boltrounder]

To anyone with the P0871 code who is in the same situation as some of the folks in this thread– I MAY have an answer… I just went through this whole nightmare with my ‘07 Ram 1500 2WD, 4.7L, 545 RFE trans, with 187,000 miles on it…
My trans was burned because I kept driving my truck while I was trying to figure out the code issue. So it cost me $6K for a new one… When I got my truck back, I was elated, except a couple days later, BOOM!…
There it was again. “P0871”… WHAT?! Did I just WASTE $6000?!?… So this time it went right back to the shop, and they were very surprised and chagrined about it. They ordered a brand-new OEM valve body & solenoid unit, installed it, and not only did the code pop right back up, but it seemed to be getting worse… So the shop put 4 guys on it, tracing every single wire and circuit for two days, and FINALLY— just as they suspected, it WAS a wiring harness problem. On my truck the part of the harness connected to the trans travels along my right bank of cylinders, then drops down behind the engine to connect to the trans.
RIGHT WHERE it turns the corner to drop down, at the back of the engine, the harness has been rubbing on the back of that right (passenger) side cylinder head, where there’s a sharp edge from the casting– and after 19 years, it finally wore through that plastic wrapping they bundle the harness in, through the wire insulation, and caused a tiny little short circuit in that wire, causing the error message and the valve body to stick CLOSED at all times…
Once they patched that, and secured the harness away from the engine block with ties, then took it for a very long test drive (1/2 tank of gas), the problem is “cured.”
I hope this helps save somebody some time, frustration, and maybe the $6000 that I had to spend…

 

[olyelr]

Good to know, thanks for posting!