Ram Transmission Control Module (TCM) users and results

mass-hole · **Posted:** Wed Mar 30, 2016 8:19 pm

95Z28A4 wrote:

f5hunter wrote:

I picked up a Ram TCM a few weeks ago and pretty much concur with what others are saying. It has shown me how much I hate the F37 flash. I really like the how it shifts quickly into 5th and locks up the converter as well as the firm and responsive shifts. I could live with the higher RPM from 1st-2nd as well as the inability to use full throttle if it was just myself driving...however I am very hesitant to let somebody else drive this without them understanding how this TCM works. It is just too easy to be heavy on the pedal and rev it over 4000 RPM's. I am pretty sure I am going to send my F37 TCM to GDE to be programmed and will put this one up for sale in the next week or so in case anybody is looking to buy one.

GDE can tune the Ram TCM to work with your CRD. Last year, I purchased a 2003 Ram TCM and a spare 2006 CRD TCM. I sent both of them to GDE. I sent the Ram TCM for Keith to retain and experiment with and the CRD ECM for an ECO tune. I am currently running the GDE ECO TCM tune and am very pleased with it. Keith has since loaded the CRD ECO tune in the Ram TCM and tested it in their CRD. He has told me (via email) that the Ram TCM took the ECO tune and works in the CRD without issue.

Personally, I would have the Ram TCM tuned and keep the CRD ECM as a spare. I kept my original CRD TCM as a spare.

GDE was unable to flash my RAM TCM with their tune so it would not say that this applies to all RAM TCMs. They were able to flash it with the CRD's factory pre-F37 tune but then could not get it to take the changes from their tune. I ended up having to send out my stock CRD TCM to them after they sent my RAM one back with the Factory tune on it. So the Ram tcm now functions as a normal CRD tcm just without the GDE Eco tune.

Mine was P/N: P56029053AE

WWDiesel · **Posted:** Thu Mar 31, 2016 4:17 pm

WWDiesel wrote:

Anyone know the year model spread on the Ram TMC's that can be reprogrammed and used in the Jeep CRDs??? :?:

Got this answer from a friend that might be of some interest to others looking to pick up an extra TCM to be reprogramed? :wink:

Quote:

The TCM is identical in hardware for Jeep Grand Cherokee, Ram Pickup and Liberty's for several year models, differing only in the code installed.

The years I found that would work were 2002-2003, 2004 and 2005. The Ram Hemi switched to an integrated ECM/TCM in 04 or 05 IIRC, but the TCM from 2003-2004 GC should work in the Liberty.

Another interesting fact is that the 2002 - 2004 TCM's have the shift maps for several different vehicle already loaded into them. The TCM queries the ECM on power up and loads the correct shift map. The exceptions would be for vehicles not yet introduced, say a CRD shift map on a 2002-2004 GC or Ram Hemi TCM, since the 2005 CRD was the first US model with that shift maps.

flash7210 · **Posted:** Sun May 29, 2016 7:19 pm

I bought a Ram TCM off eBay for $25. It arrived yesterday and I installed it today.
Definitely shifts a lot differently. Gonna take some getting used to.
Having the transmission in 5th with TC locked at 48 mph is interesting.

Jett · **Joined:** Fri Apr 17, 2020 12:07 am **Posts:** 250

Wow nobody tried this in 4 years? Got mine today in the mail. Pins were rusty so cleaned them up a little and slammed it in. Interesting so far. Didn’t do any high speed or hard take offs yet. One thing that will hopefully smooth out is the jolt putting it into gear from park. It’s quite a thud. But I like the feeling of forcing the shifts with a throttle foot lift. That’s exactly how I try to drive all autos and most of them don’t appreciate the help.

WWDiesel · **Posted:** Sun May 24, 2020 1:36 am

Jett wrote:

Wow nobody tried this in 4 years? Got mine today in the mail. Pins were rusty so cleaned them up a little and slammed it in. Interesting so far. Didn’t do any high speed or hard take offs yet. One thing that will hopefully smooth out is the jolt putting it into gear from park. It’s quite a thud. But I like the feeling of forcing the shifts with a throttle foot lift. That’s exactly how I try to drive all autos and most of them don’t appreciate the help.

Be real careful, I remember some warnings about the engine being able to over rev above the red line when down shifting under power with the Ram TCM. :juggle:

Jay ne Ohio · **Joined:** Sun Dec 12, 2010 5:49 pm **Posts:** 216

Jett wrote:

Wow nobody tried this in 4 years? Got mine today in the mail. Pins were rusty so cleaned them up a little and slammed it in. Interesting so far. Didn’t do any high speed or hard take offs yet. One thing that will hopefully smooth out is the jolt putting it into gear from park. It’s quite a thud. But I like the feeling of forcing the shifts with a throttle foot lift. That’s exactly how I try to drive all autos and most of them don’t appreciate the help.

It sounds like you need to do a transmission quick learn to calibrate the TCM to the clutch volumes. Yes it will eventually learn it, if you don't burn up a clutch first........ Find someone with a scantool to do the quick learn.

Jett · **Joined:** Fri Apr 17, 2020 12:07 am **Posts:** 250

WWDiesel wrote:

Jett wrote:

Wow nobody tried this in 4 years? Got mine today in the mail. Pins were rusty so cleaned them up a little and slammed it in. Interesting so far. Didn’t do any high speed or hard take offs yet. One thing that will hopefully smooth out is the jolt putting it into gear from park. It’s quite a thud. But I like the feeling of forcing the shifts with a throttle foot lift. That’s exactly how I try to drive all autos and most of them don’t appreciate the help.

Be real careful, I remember some warnings about the engine being able to over rev above the red line when down shifting under power with the Ram TCM. :juggle:

I’ve read some things mentioning this too however they said things like 4500 rpm which for an over rev I don’t think that would really be bad for a small diesel like this. It’s well beyond the operational rpm but that has more to do with the power curves and efficiency windows of any diesel than it does for the mechanical limitations. I think these engines should have no problem doing quick stints above 5k or even more without any risk of damage don’t you? I just don’t see what would break on a diesel vs any other engine really in terms of over speed. It’s unfortunate that these modules all take so long to learn, makes back to back testing a little difficult.
So if any TCM is removed from car it will be reset and need to learn in again correct? This makes the concept of switching TCMs based on the needs of the day a little less likely. My thought was the f37 TCM might actually be good for towing for instance, and could be swapped in without much trouble when needed, but if each time it takes two weeks of driving carefully then that may be a no go. If I can make the hemi tcm work for towing then it might be ideal however. And for 25$ it’s a fun experiment anyway.

Also, regarding over rev, aren’t the engines protected from over rev by the ECU anyway?

WWDiesel · **Posted:** Sun May 24, 2020 5:31 pm

I plugged in a used TCM I bought in mine and there was no "relearn" required, it did not happen.

As for over revving, the ECM cannot protect it from a slingshot effect of a sudden downshift under power.
The reason diesel engines don't like and are not designed for higher rpm's, they are generally long stroke engines and have longer rods then their gaser counterparts.
Over revving with long rods (rotating mass) can have devastating results.
I very rarely ever even allow mine to rev to over 3k.
A diesel engine generally makes its peak torque (power) at lower rpms and therefore does not need to rev to higher rpm's just to make HP.
In some cases, revving to higher rpms can actually hurt you on actual performance.

Could not find a torque/HP chart for the VMI 2.8, but found one for the GM 2.8 diesel.
this shows how rpms can affect performance as rpms increase. Torque drops off quickly.

TURBO-DIESEL-FREAK · **Joined:** Sat Apr 17, 2010 3:29 pm **Posts:** 1167

FOLLOWING...

Jett · **Joined:** Fri Apr 17, 2020 12:07 am **Posts:** 250

That’s true about the stroke but this is a pretty high performance diesel and it has a stroke of 3.95” and when compared to a Toyota Tacoma 2.7 engine they are 3.75 stroke so only 2/10” longer. I just don’t see spikes to 4500 for a few seconds being detrimental but I’ll be watching for them. I know I saw upper 3’s today and the engine was very smooth and calm actually. That counterbalance assembly does a good job. My last car was a Suzuki 2.0 and it was a racket that sounded like it would blow up at those revs lol.

So how can I tell a f37 from a original factory tune? I need to figure out if this other spare tcm is a f37 or not. It seems to shift into top gear a little lower but I can’t tell.

flash7210 · **Posted:** Mon May 25, 2020 5:47 am

Quote:

but this is a pretty high performance diesel

Now that I’ve regained my composure...

It’s less about stroke an more about rotating mass.
And there’s a lot of it in the VM 2.8.
I’m sure it could handle a few short blips up to 4500. Just don’t make a habit of it.

There is no relearn for the Ram TCM.
Rather, YOU relearn how to operate your CRD.
It’s not bad. I’ve driven mine for years with the Ram TCM.
Over flat land it’s not a problem.
But if you regularly drive through hills and mountains you might hate it.
You will learn the threshold of throttle position vs downshifting.
You will learn to think ahead about what gear to be in when passing or approaching a hill.
You will learn to drive with OD-off more frequently than before.
Or maybe that’s all just me.

In any case, it you hate it you can always switch back.
Just be careful when loosening the bolt on the TCM connector. A few here have stripped the threads.

Jett · **Joined:** Fri Apr 17, 2020 12:07 am **Posts:** 250

flash7210 wrote:

Quote:

but this is a pretty high performance diesel

Now that I’ve regained my composure...

It’s less about stroke an more about rotating mass.
And there’s a lot of it in the VM 2.8.
I’m sure it could handle a few short blips up to 4500. Just don’t make a habit of it.

There is no relearn for the Ram TCM.
Rather, YOU relearn how to operate your CRD.
It’s not bad. I’ve driven mine for years with the Ram TCM.
Over flat land it’s not a problem.
But if you regularly drive through hills and mountains you might hate it.
You will learn the threshold of throttle position vs downshifting.
You will learn to think ahead about what gear to be in when passing or approaching a hill.
You will learn to drive with OD-off more frequently than before.
Or maybe that’s all just me.

In any case, it you hate it you can always switch back.
Just be careful when loosening the bolt on the TCM connector. A few here have stripped the threads.

I take it you don’t agree about the performance? I’m just basing that on the many diesels I’ve had in my life and this one is higher performing than all but maybe the 2.1 Mercedes in my van. Admittedly I’ve had some pretty old diesels. But even the venerable Cummins 5.9 was only 160hp in stock form. At over twice the displacement.

But that’s off topic anyway. I’m more concerned that you don’t think there’s a learn-in for the tcm. This is in direct conflict with everything I’ve read about them. Do you think there is no learning for any of them or just the hemi?

BTW you come off a tad socially inept when you laugh in someone’s face over an innocuous comment, just saying.

flash7210 · **Posted:** Mon May 25, 2020 2:20 pm

Sorry. Didn’t mean to be an A55.

The Merc 2.1L, with almost 100 HP per liter, fits in the high performance category.
It’s just when you dig into CRD engine and find all its shortcomings it’s just not that impressive. Both in performance and durability.
Hence why no one recommends revving it above 4000 rpm.

With the Ram TCM. I’ve tried the recommend “learning” procedure. The only thing that got learned was me.
I’m not knocking it. Been running with it for years.
But I never saw any increase in MPG. Probably because I do most of my driving at 60+ mph.

If you want your CRD to last a long time, go easy on it.
I’ve ran the hell out of mine and it has a ton of miles on it. But I can no longer consider it to be reliable transportation.

Jett · **Joined:** Fri Apr 17, 2020 12:07 am **Posts:** 250

flash7210 wrote:

Sorry. Didn’t mean to be an A55.

The Merc 2.1L, with almost 100 HP per liter, fits in the high performance category.
It’s just when you dig into CRD engine and find all its shortcomings it’s just not that impressive. Both in performance and durability.
Hence why no one recommends revving it above 4000 rpm.

With the Ram TCM. I’ve tried the recommend “learning” procedure. The only thing that got learned was me.
I’m not knocking it. Been running with it for years.
But I never saw any increase in MPG. Probably because I do most of my driving at 60+ mph.

If you want your CRD to last a long time, go easy on it.
I’ve ran the hell out of mine and it has a ton of miles on it. But I can no longer consider it to be reliable transportation.

No worries, I know we sometimes act differently online and don’t even realize it.
Well, I’m kind to my engines in some ways, however I want to be able to lean on them when needed, and this crd will be used to tow heavy at times so I have to keep that in mind. If it’s true that the modules don’t learn then that’s actually great news for my scope of use because I could potentially swap them around depending on if I’m towing or using in mountains and then swap back for city.
So after many miles you don’t consider it reliable, what are the main areas that you’ve found lacking? I know about the tyranny issues but they seem solvable with about 1200$ in parts, which isn’t too awful imo. I’ve read about a few thrown rods but the engine seems to be pretty solid after you get the silly stuff off it like EGR and the funky T stat.

WWDiesel · **Posted:** Mon May 25, 2020 3:48 pm

Jett wrote:

So after many miles you don’t consider it reliable, what are the main areas that you’ve found lacking? I know about the tyranny issues but they seem solvable with about 1200$ in parts, which isn’t too awful imo. I’ve read about a few thrown rods but the engine seems to be pretty solid after you get the silly stuff off it like EGR and the funky T stat.

The elephant in the room, the Exhaust Valves!
You can do every normal maintenance service and upgrades to this engine like timing belt, pulleys, idlers, water pump, rockers, intank lift pump, ProVent, and most anything else you can think of.
But if you like me are still running on original exhaust valves, it is a ticking time bomb. And you do not know if or when it might drop a valve. :grim:

Some have gone well over 200k with no reported dropped valves, and some have dropped one between 100k - 150k. Unfortunately here is no set age or mileage determined. :banghead:

Some have simply had to replace the head with new valves when this happens, and some have lost the head & piston, and some a head & piston and the piston liner, and a few worse case have had the valve go through the piston and then out the side of the block totally destroying the engine. $$$$$ :dead:

One reason I do not think it is good idea to routinely test or exceed the operational design parameters of this engine!
:5SHOTS:

flash7210 · **Posted:** Mon May 25, 2020 4:39 pm

Jett wrote:

flash7210 wrote:

I’ve ran the hell out of mine and it has a ton of miles on it. But I can no longer consider it to be reliable transportation.

So after many miles you don’t consider it reliable...

Its not reliable because of the high mileage, break downs are more frequent, and being down for weeks at a time waiting for parts.
Now, my wifes 06 CRD still has less than 100K miles and is purely a grocery getter.
By comparison it is much more reliable even though it has some worn suspension parts that need attention.

Mine has never had a serious transmission problem.
Its still on the stock torque converter and it will shudder, but I can manage that with the throttle.
It also has the common fluid drainback problem, but I can manage that my letting it idle for a minute to get the fluid pumped up.

Mine has never kicked a rod or dropped a valve.
The bottom end has been pretty solid.
However I did have a cracked head and therefore had to find a replacement head.
Then fuel system components started failing.
Then the busted oil cooler...
You get the picture.

Ram Transmission Control Module (TCM) users and results

Who is online