2021 RAM 2500 - 68RFE With P0871 Code?

[abafify1990]

Hello everyone, I have a 2021 RAM 2500 that I've bought brand new.

It was tuned since 500 miles, currently at 52,000.

I had installed a BD diesel plate kit to get my line pressure up to 250 when I first tuned the truck; the truck ran perfectly fine for the past 3threeyears.

I recently decided to get a full billet VB from ATS with a new solenoid pack.

I did not have the time to swap it out myself, so I took the VB to a local shop for the swap.

Now, I'm getting the P0871 code that comes on when I take off from a stop light.

I've never had this code come up, and the shop that did the installation is trying to tell me my transmission pump is going out and that it's time for a new transmission.

I need some opinions on what you guys think.

I've seen posts here that had the code come up, and their solution was to replace the valve body, so I'm not sure why I'm getting the code on mine with a new VB installed.

Any thoughts on what it could be?

Do you think the shop might've messed up during installation, causing the codes?

I appreciate any help you can provide.

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[Corkey]

The PCM is detecting low voltage from the pressure switch "C."

Edit: Check the fluid level in the transmission.

It can also be generated from low to high pressure, which the VB from ATS could be a tuneless option, as it's now popping a code from the higher line pressure.

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[AK Bob]

See the attached troubleshooting information for the P0871 trouble code.

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[abafify1990]

@Corkey I checked the fluid the same day I picked it up from them, and when warmed up, it was up around the hot marker.

My CTS edge shows that line pressure goes up to 250 just fine when getting on it and idling around 120.

@AK Bob, thanks

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[abafify1990]

The PCM is detecting low voltage from the pressure switch "C."

Edit: Check the fluid level in the transmission.

It can also be generated from low to high pressure, which the VB from ATS could be a tuneless option, as it's now popping a code from the higher line pressure.

Sorry, can you dumb it down for me?

What do you mean by a tuneless option?

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[Corkey]

Sorry, can you dumb it down for me?

What do you mean by a tuneless option?

I would go with what Bob had supplied for you.

I was trying to toss out ideas on a quick search related to the code you have.

Some valve bodies are tunable, and some are not.

The ones that are not are done in-house at ATS.

If you have transmission tunes applied over the stock or pre-programmed valve body, you could experience some oddball behaviors.

This code didn't appear until after installing the new ATS VB, so I tossed out a theory.

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[Jwaller]

Hi, I did some research on Google about this, as I’ve had some weird trans codes on my 2021 too.

Common things that can cause the P0871 could be a pressure sensor, filter blockage, or it needs a relearn, which u can do with Alfa OBD.

I’m gonna follow this cause the trans in the 5th Gens makes me nervous!


Sent from my iPhone using Tapatalk

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[m00n]

Ironically, I remember this video popped up on my feed a few days ago.

I'm not sure if it is applicable here, but good info nonetheless and might help others in the future.



Hope ya get your issue figured out and that it's nothing serious!

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