Bucking in 2nd gear

[Jcrawford]

So my 2020 ram 2500 Cummins on warm days, say about 70-75 degrees plus domes some weird stuff. When you start it up and pull out of a parking lot or away from a stop sign and give it only a little throttle to accelerate up to 15-20mph and then let off it starts surging and bucking. You can watch the tac swing from 900 to 1300 up and down rapidly for several seconds as the truck lurches. You pop it in neutral and it stops bucking you gear limit it to first it stops bucking. Doesn’t do it in the fall or winter, noticed it last year but it’s kinda intermittent and honestly forgot about it till it did it again this spring. Doesn’t matter if the exhaust brake is off or on or if your in tow haul mode. Am I right in thinking torque converter lock up? Once it’s out of 2nd gear into 3rd it doesn’t do it untill you come to a complete stop and take off again. I have no idea what to tell the dealer lol cus idk how often I can replicate it it, but it’s fairly regular when I leave work for lunch or at the end of the day on warm/hot days. I’d really appreciate any thoughts or theories to at least narrow it down.

 

[elephantrider]

are all recalls taken care of? light throttle surging is a known complaint.

 

[Jcrawford]

Nope I don’t think so. You know the recall? Only ones I’ve seen were cp4 and I thought one for seat belts or air bag. I’ll see what I can find

 

[Rooster Bob]

Any update on this? My truck started doing the exact same thing when it got above 90F in NJ this past week. It does it for about 10-15 minutes from start up then stops doing it completely after that. I just dropped it off at the dealer but got a less than enthusiastic response from the service tech about possible solutions/causes... As a note, it never did this before I had the HPFP recall performed three weeks ago.

 

[Jcrawford]

Nope and that doesn’t bode well for me. I’m getting the fuel pump recall in a few weeks and was hoping after the flashes it would solve my issue.

 

[elephantrider]

there were a few flashes early on that apparentlstatus. to address that issue. that's why I was asking about recall status.