Odd transmission problems 2014 ram 1500 8hp70

[Mattv]

I have a 2014 ram 1500 5.7 with 8hp70. When the truck is idling and in park, the digital speedometer says 1mph. Then when I put it into drive and go above 5mph it puts itself into park and stops me. I tried pulling the lever to keep it out of park and it does a similar thing where it revs up and stops and makes me shift into park to go back into drive. It throws an engine code (P1db3-00) when I looked it up it said it means tcm/ecu reset attempted. Trans gets up to normal temp and stays there when idling. Replaced pcm with no luck. The dealer diagnosed it as a valve body and quoted $6k. Any ideas to what could cause these problems? My best guess is the tcm which is part of the valve body but I’m not sure. Thank you for any help.

 

[star_deceiver]

Weird. You can buy a used trans for a lot less than $6k.

 

[Mattv]

Exactly. So I’m hoping I can find a solution without pulling the trans, if not I’ll find a used one to put in

 

[crackerjack1957]

Sounds like they are quoting a new transmission & install

 

[Wild one]

Exactly. So I’m hoping I can find a solution without pulling the trans, if not I’ll find a used one to put in

Be forewarned the only 8 speeds that are a direct swap into your 14 are the early 13 and 14 ones,they changed the tcm in 15,and you'd have to pull your old tcm out and re-install it in the newer transmissions.

 

[rickjkline]

Be forewarned the only 8 speeds that are a direct swap into your 14 are the early 13 and 14 ones,they changed the tcm in 15,and you'd have to pull your old tcm out and re-install it in the newer transmissions.

I had my 2014 trans changed out with a 2017 trans and they did not use the 14 tcm, it works just fine with one caveat, I dont have access to using the shift buttons on the steering column anymore.

 

[Wild one]

I had my 2014 trans changed out with a 2017 trans and they did not use the 14 tcm, it works just fine with one caveat, I dont have access to using the shift buttons on the steering column anymore.

So it doesn't work "fine" then.I don't consider that a properly working transmission there bud
If you'd swapped in your original TCM then it would work "fine"
The 8 speed with-out access to the shift buttons leaves a bit desired especially when towing .

 

[RamDiver]

I had my 2014 trans changed out with a 2017 trans and they did not use the 14 tcm, it works just fine with one caveat, I dont have access to using the shift buttons on the steering column anymore.

I'm a big fan of the ERS buttons and would likely pay more money to keep them functional.

.

 

[rickjkline]

So it doesn't work "fine" then.I don't consider that a properly working transmission there bud
If you'd swapped in your original TCM then it would work "fine"
The 8 speed with-out access to the shift buttons leaves a bit desired especially when towing .

Splitting hairs I think. not saying it was the correct action but it does in fact work. The shop that installed the trans said it didn't need swapped out. When I noticed the issue the shop had already disposed of the TCM. I didn't want to spend more money on a feature I didn't use.

 

[jeremyschneider]

If you pull the chrysler part numbers for the complete trans with tcm they are now all superceded to the same part number im sure. I just swaped a 13 into an 18 with zero issues i was skeptical as all my used parts contacts say they dont, the dealer looked up both replacement transmissions by vin and superceded to the same part number. I have run into tcm issues from year to year with ecodiesels though.

Just my 2 cents