Advice?

[Jesusplusnothing]

Our 8spd transmissions are known to run hot regardless, and if you're towing and/or hauling heavy, they can get even hotter. As I'm sure you know, heat kills transmissions

Plus, the existing thermostat valve in the transmission cooler is a known issue and if it seizes you'll cook your transmission.

@caulk04 is a highly respected member of this community, and his designed trans cooler bypass valve is fantastic. I have one, my stepdaughter has one, my buddy has one, too. We all immediately got the benefits of the reduced trans temps.

Many on in this community utilize his product and have nothing but great things to say about its benefits.

Reach out to him and he will get you sorted

You're giving me lots of helpful information thank you very much. I was wondering why it never did it when the trans was cold. Interesting I shall reach out to him thank you again!

 

[caulk04]

Thanks all! For anyone else reading, check out this website for bypass valves: https://yourautohuckleberry.com

 

[Sherman Bird]

Thank you for that information. Maybe I can use that to argue my dealer into turning the mds off lol.

you can do that if I recall correctly.

 

[Jesusplusnothing]

you can do that if I recall correctly.

Turn it off myself?

 

[Tulecreeper]

The 2019 and up do not have the ability with a tuner to turn off the MDS. The only way to turn off the MDS in the 2019 and up 5.7 Hemi's, is by replacing the ECM,ECU,PCM. On average a new ECM costs around $650.00....**However the moment you do that, you VOID your manufacturer warranty** So give it serious thought before you do, unless your filthy rich and don't care about no warranty.
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The cut off is 2015+. I used my Diablo tuner I had for my 2011 300C for our 2014 RAM 1500. When we got the ‘18 I discovered the Diablo no longer worked without an unlocked PCM.
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MDS - fix it or turn it off

Recently my truck started to make what has been described as a ratcheting sound off throttle ECO light on, goes away in neutral and if selecting a gear or giving more throttle... did lots of research and based on when it happens and how I can get it to go away it is the MDS. I have 150,000...

www.ramforum.com

 

[Jesusplusnothing]

The 2019 and up do not have the ability with a tuner to turn off the MDS. The only way to turn off the MDS in the 2019 and up 5.7 Hemi's, is by replacing the ECM,ECU,PCM. On average a new ECM costs around $650.00....**However the moment you do that, you VOID your manufacturer warranty** So give it serious thought before you do, unless your filthy rich and don't care about no warranty.
---------------------------------------------------------------------------------------

The cut off is 2015+. I used my Diablo tuner I had for my 2011 300C for our 2014 RAM 1500. When we got the ‘18 I discovered the Diablo no longer worked without an unlocked PCM.
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MDS - fix it or turn it off

Recently my truck started to make what has been described as a ratcheting sound off throttle ECO light on, goes away in neutral and if selecting a gear or giving more throttle... did lots of research and based on when it happens and how I can get it to go away it is the MDS. I have 150,000...

www.ramforum.com

DiabloSport 32456 Pulsar XT for Ram 1500

Pulsar XT is an all-new take on drivability and calibration for your 3.6L and 5.7L Ram 1500. Unlike any other device on the market, Pulsar XT is an innovative inline module engineered to keep your factory PCM untouched, with no PCM swap or unlock required. This is the most advanced and easiest...

www.holley.com

I haven't watched any videos on install but given what you sent I'm assuming this effects the ecm some how?

 

[turkeybird56]

Like many have said, this points to the awful MDS system inherent in our vehicles that affects our 8spd transmissions. Some feel it more than others, but it's a defined aggravation IMHO.

I also feel that it can't help ones transmission kicking in and out, shuddering and feeling like it's stumbling as it's trying to engage the transmission to get into the right gear for the applied load and speed.

These transmission feelings are also more pronounced at low speeds like in-town driving and traffic.

In 4.5 years of ownership I never use the MDS, and it's marginal at best that it saves any fuel whatsoever. So little that I don't care to utilize this useless technology as my driving enjoyment far outweighs any perceived benefits that MDS is purported to provide.

Put it in 8 and enjoy your new Ram ownership experience

DITTO !!!!!

 

[Jesusplusnothing]

DITTO !!!!!

So would you cancel an appointment for a possible 3 day diagnostic they wanna do at my dealer?

 

[turkeybird56]

So would you cancel an appointment for a possible 3 day diagnostic they wanna do at my dealer?

I am not the one who has just bought a 50-75K brand new 2024 truck, that is a decision only U can make. I know on MY 19, which is one of the first built trucks in April 2018 I do not hear any thud. BUT I try to always hit ERS to 8th gear in town. On highway, at the speeds around here, I would never notice as average slow speed is 80 MPH. Just being honest. I live rural with only a small town near. Any "big" town is 1-2 hours away.

 

[DanAR]

Does the ECO light coming on indicate the motor has engaged the MDS deactivation of cylinders? When it goes off, all cylinders reactivate?

 

[Tulecreeper]

Does the ECO light coming on indicate the motor has engaged the MDS deactivation of cylinders? When it goes off, all cylinders reactivate?

Yes, that is my understanding. But you can stop that ECO light from coming on in your Settings menu, even if you choose to leave the MDS as it is.

 

[Jesusplusnothing]

Does the ECO light coming on indicate the motor has engaged the MDS deactivation of cylinders? When it goes off, all cylinders reactivate?

I'm assuming that's the case?

 

[DanAR]

OK - then in that case it does engage at very low speeds. That’s nuts.

 

[Tulecreeper]

OK - then in that case it does engage at very low speeds. That’s nuts.

Yes, mine engages in stop-and-go traffic in town. You can't convince me that switching between 4-cyl and 8-cyl at random speeds every couple of minutes is good for it, so I just fixed that issue by engaging my ERS every time I get in.

 

[CanuckRam1313]

^^^ This!

 

[DanAR]

I purposely engage my ERS (-8+) as soon as I put it in gear - which disables the MDS - and I have had zero issues. I can't imagine when I would ever want my truck to run on 4 cylinders. Besides, when the MDS kicks in I hear this "growling" sound from behind the firewall and there is a change in my throttle pedal and that bugs me.

Can you elaborate on this process a little more. What does ERS stand for in this case?

 

[Wild one]

Can you elaborate on this process a little more. What does ERS stand for in this case?

Electronic range select,if you have an 8 speed,it's the Up/Down buttons on the right side of your steering wheel. Pushing the buttons till you see "8" on your evic,disables the MDS,but allows the transmission to still shift up and down through all the gears

 

[jr27236]

I know and I'm gonna. Just more wondering what I could tell the dealer to start looking at. From reading a thread about it from 2019cthere is no "fix" just it may go away it may not. Seems to be a software thing in the transmission. No dealer around my city has ever heard of it before though so idk.

Love when the dealers say "they never heard of this" lmao. They are all clowns

 

[Jesusplusnothing]

Love when the dealers say "they never heard of this" lmao. They are all clowns

I can't disagree with that. I took it for a drive today. I wonder if it's getting softer or whatever the more miles I put in it. I didn't feel it once today with mds on.

 

[Musky Mike]

FWIW, on my 2019, sometimes I don't notice the MDS disengaging and sometimes I hear the "thud". I will say that I only leave MDS engaged on the highway as I find it annoying going in and out all the time the when I'm in town or on the country roads. On the highway MDS does add 1-3 mpg because it says engaged long enough to make a difference. Oh, and it has nothing to do with the transmission, when I hear the "thud" the transmission never changed gears, RPM never changed.