2021 2500 6.4 new issue

[Redfour5]

I noticed that on two separate occasions when my wife was driving my truck and i was riding shotgun after I had a few drinks. Both times it was at a slow speed and it bucked/surged a handful of times. It was like being in one too high a gear and letting out the clutch.

I chalked it up the truck/trans mapping being accustomed to my driving and she was probably lighter on the fuel and it upshifted funny or something. I’m not 100% sure if that’s what happened but I’ve not experienced it from the driver seat.

I also have 30k miles over the last 4 years ownership.

I was going to say it might be the "mapping" causing it as you noticed it with your wife driving AND in different terrain the "learning module" was unfamiliar with. But two weeks in different terrain? I'm not sure how long it takes to adapt but that seems longish...

 

[william_beaux]

Old thread, but also experiencing this in a 2022 6.4 with 4.10s, 7000 miles on the truck

I have felt it consistently since day one. Light throttle acceleration about 30mph - 3rd and 4th gear - while MDS is bypassed with gear selection. If you have ever driven a manual transmission, it feels similar to being in too high a gear at too low an RPM, but it's very subtle.

In the same gear range, I can frequently feel my torque converter unlocking when coming to stop, so I have attributed the stutter to that as well. I also read on this forum of a flash being released in early 2023, but I don't believe that has happened. I was at the dealer last week and no mention of an update when I inquired.

 

[matemike]

Dealers are not going to know. They were trying to get my cargo camera fixed and saying my truck was on latest radio software...swore up and down I needed a new radio. I asked on here and found out I was two software versions behind. I then looked at my service dept papers closer and saw that they were investigating a 2019-2021 truck. Mine is a '22. I updated my radio with help from UConnect and fixed it myself. The dealership still won't admit that they were not even looking at the right stuff. And I showed them the cargo camera was working now and they said it always was. Like I was lying to them. They still insisted I swap the radio. I said no thank you.

Got a call a couple weeks later saying my new radio was in...I read them the riot act for not listening to me.

I asked about a trans flash middle of last year and they said it already came out and that they flashed my truck...wtf? WHEN? They hadn't had my truck in there for a year. They said they did it over the air. again, wtf, I cannot express my discern. Clueless people working at the dealerships.

 

[kevin588127]

Old thread, but also experiencing this in a 2022 6.4 with 4.10s, 7000 miles on the truck

I have felt it consistently since day one. Light throttle acceleration about 30mph - 3rd and 4th gear - while MDS is bypassed with gear selection. If you have ever driven a manual transmission, it feels similar to being in too high a gear at too low an RPM, but it's very subtle.

In the same gear range, I can frequently feel my torque converter unlocking when coming to stop, so I have attributed the stutter to that as well. I also read on this forum of a flash being released in early 2023, but I don't believe that has happened. I was at the dealer last week and no mention of an update when I inquired.

Waiting patiently to hear about this as well. Mine is like yours and if I didn't know better, I'd think the trans was slipping because that's what it feels like when operated in that range. I won't even bother with the dealer until I know it's a thing. I had to hold their hand to get a PCM update on my wife's 2015 town and country. Same deal, a simple programming change solved it's weird shifting problems. I actually brought it in told them about an update. They called and said their was no update, I gave them the TSB number that I got from all data and then they could find it.

 

[Mdim]

Mine does this when I first start driving. 6.4 hemi with about 100k miles on it. First mile or so if I am light on the gas it kind of surges a bit. Goes away as the trans warms up. Assumed was just cold fluid or something but definitely not something I've experienced in other vehicles.

 

[william_beaux]

Anyone have an update on the firmware update, or if Ram has acknowledged an issue? The issue has become much more noticeable - approaching the time to take it to dealer.

 

[psh717]

Disable HILL START ASSIST!!! I just disabled “HILL START ASSIST” in the vehicle menu & the transmission is shifting normal now. I was experiencing shuddering and awkward shift points where the transmission didn’t quite know if it wanted to shift or not, as well as some jerking. Disabling “HSA” appears to have FIXED the issue so I’d try this first before contacting a dealer. I have a 2022 Ram 2500 6.4 I just bought used with 15k miles. It has every update/patch as of April 2024. I inadvertently enabled HSA while playing around with settings and that’s when this weird shifting/shuddering mainly between gears 2-5 & weird downshifts. I was seriously thinking the transmission had to be a lemon but it appears Hill Start Assist is a defective setting that’s interfering with the transmission is a very bad way. Worth a shot. I’ll update this post/thread if the issue returns (w/ HSA disabled).

 

[Hunter11]

I just went out and disabled mine. I won't drive it again until next week but will see of I notice any difference. Thanks for the tip.

 

[matemike]

Thank you @psh717
I disabled my hill start assist (I must have turned on every possible feature the day I took ownership of my truck in May 2022 and have not revisited HSA).
I just now drove with it off for the first time. I went 38 miles...it was about 6 miles through town with stop lights and signs, 26 miles highway, then 6 miles back through town to get home. Everything in my truck's drive train feels a ton better.

If this was the fix all this time then I must admit I have a world of emotions right now.

I am ecstatic that my truck transmission and rear differential finally feel smooth.
I am Worried that I did damage by driving with the hill assist on for 27.5k miles.
I am aggravated that Ram service departments and manufacturers themselves have not sent out a circular or notice, nor scanned it off the software already.

However I’m still a tad skeptical because every definition of Hill Start Assist for Rams that I can find says it keeps the brakes applied while the vehicle is stopped and you transition from holding the foot brake to applying the throttle so the truck doesn’t start to roll down hill whilst the brakes were otherwise “not applied" during the foot transition. It has nothing to do with the transmission timing or "thinking". But I know it was said that it's a defective software issue causing transmission problems. Hope so. Hope ram will repair my truck if anything was damaged during this HSA time period on my truck.

I will run a few Saturday errands tomorrow and report back. Making 2 to 3 mile trips around town on a cold trans were always the worst experiences when describing my issue. So tomorrow will be a solid test for me.

If it runs smooth and to my liking all weekend then I will do my part and report back here as well as bring myself and my truck and show my local dealer techs in the service department this issue repair. Hopefully they take it to heart and can help others who have come in with wonky 8 spd transmission shifting.

Thanks again. @psh717 . you might be a hero

But you have to tell me; where did you find a '22 with 15k miles? I have almost double that on mine and we are a 4-vehicle family with only 2 drivers. I don't think I drive my truck a whole lot. lol

 

[matemike]

Yes Yes Yes is all I can say.

Deactivating the HSA has made my truck shift and drive much smoother. Happy customer again.

 

[whitexc]

I went out and disabled mine. I didn’t drive it and may not for a few days but interested in seeing the change if any. Thanks


Sent from me

 

[Rockcrawlindude]

I turned it off on my 19 and it didn’t seem to change anything. FWIW I’ve not had the complaints these folks are talking about I just wanted to see what this was about.

 

[whitexc]

I turned it off on my 19 and it didn’t seem to change anything. FWIW I’ve not had the complaints these folks are talking about I just wanted to see what this was about.

Pretty much where I’m at. I have noticed a few times the transmission gets a little wonky. Nothing terrible just confused on what it wants to do. We’ll see if it changes anything.


Sent from me

 

[Hunter11]

I drove mine today for the first time since turning HSA off and I have to say I did not notice any of the surging I have been dealing with. Could this be something that only effects the ZF transmissions as opposed to the previous models?