CRD Transmission Modulator Can't Be Fixed

ohitsbrittany · **Joined:** Fri Aug 31, 2012 5:56 pm **Posts:** 4

Has anybody had a problem with their Jeep Liberty CRD's Transmission modulator going out? I have been having problems with my '06, a few months ago when I was driving it would suddenly lose all power, my engine would rev to 3k rpm but would not shift, this would happen at random times during a commute and would take forever to get up to speed. Restarting the vehicle would fix the problem temporarily so I figured it was a computer problem. When I took it to a repair shop, they could not find anything wrong with it. Eventually my car broke down on my way home, this time my vehicle would speed up to 40 mph and die out, this time my check engine light came on. I took it to the auto shop again and they said that 1. the transmission modulator went out 2. the crank position censor went out and 3. the fuel filter needed to be replaced. It was a brand new fuel filter probably only 400 miles on it. They did not have the program for the transmission modulator so they sent it to a Jeep dealership. Jeep was having problems with the modulator accepting the program so they sent it to Chrysler's main repair shop. Chrysler finally determined that the new modulator was a lemon and replaced it, the second new one accepted the program. Today I was supposed to pick my Liberty up and it broke down on its way to the auto shop from Chrysler. The same issue, all power being lost, only speeding up to 40mph. Does anybody have any clue what may be the problem?

Big Montana · **Posted:** Fri Aug 31, 2012 7:33 pm

What's the modulator? Is that the TCM or is it the "heart" of the transmission that controls all of the fluid flow and pressure? My "heart" went out around 30k, and I didn't even stall out. I just had a check engine light and that's what they replaced.

I'm not even sure if what I said makes sense. I just remember telling my brother, the Chrysler transmission calibrator, that they replaced a part on my trans under warranty and he said "oh that's quality. That's like the heart of your transmission."

Big Montana · **Posted:** Fri Aug 31, 2012 7:36 pm

Oh, I forgot the point of my question. Have you done any fluid changes to your trans lately? Could you have messed up the mechanics or do you think that this is all electric?

It seems strange to me to have three systems affected at once. Fuel, trans, and crank sensing? Are they just searching?

ohitsbrittany · **Joined:** Fri Aug 31, 2012 5:56 pm **Posts:** 4

They told me that the transmission modulator was the computer that controls the transmission. I have not done any fluid changes to my transmission lately, I do believe it is electrical. But then again I'm only 19 and have very little car experience and knowledge, just based on restarting the vehicle alleviated the problem makes me think it was computer/ electrical.

Dennis MacGyver · **Posted:** Fri Aug 31, 2012 9:37 pm

IF the stock TCM (transmission control module)(part # 56044737AI) is bad, the high mileage guys here would say to replace it with one out of an '03 Dodge Ram 1500 with a 5.7 liter engine. My current TCM is fine (has F37 up-grade) in my '06, but I'm changing mine out to aforementioned one this weekend. The part number is 56029053AD. They can be bought on Ebay for about $70 with no core charge. Shift points are lower with 5th lock-up at 47 mph, IF you behave yourself.

PM racetracer or warp2diesel for more info on this TCM swap-out. Racetracer is so impressed with his that he's selling or sold his GDE upgaded, stock, TCM

ohitsbrittany · **Joined:** Fri Aug 31, 2012 5:56 pm **Posts:** 4

They replaced my TCM at Chrysler, as they were driving it back to the autoshop I sent it to begin with it broke down once more and now they have no clue what is wrong with it. They have had my vehicle for almost a month now.

Kgeisler2010 · **Joined:** Sun Sep 04, 2011 9:56 pm **Posts:** 66

i have a tcm from a 03 ram for sale that i had on crd for awhile if ur interested

ohitsbrittany · **Joined:** Fri Aug 31, 2012 5:56 pm **Posts:** 4

they just installed a new tcm

Billwill · **Posted:** Sun Sep 02, 2012 4:47 am

ohitsbrittany wrote:

they just installed a new tcm

TCM stands for Transmission Control Module.

As far as I know....I do not have an auto but have read a lot about them....the PCM needs to "learn" the state of the transmission but I doubt that would cause a major problem such as you have.

Sounds like you have a mechanical problem with the transmission....may just need a flush, filters replacing, new correct fluid and a re-learn of the transmission. Or the transmission needs to be overhauled or replaced.

striperman36 · **Posted:** Sun Sep 02, 2012 10:26 am

Kgeisler2010 wrote:

i have a tcm from a 03 ram for sale that i had on crd for awhile if ur interested

Why are you selling it?

ChooChooman74 · **Posted:** Sun Sep 02, 2012 10:28 am

I just bought one off a 2500 ram. Should be in by next week.

Sent from my DROID BIONIC using Tapatalk 2

striperman36 · **Posted:** Sun Sep 02, 2012 10:34 am

ChooChooman74 wrote:

I just bought one off a 2500 ram. Should be in by next week.

Sent from my DROID BIONIC using Tapatalk 2

Your'e killin me :jester:

racertracer · **Posted:** Sun Sep 02, 2012 6:15 pm

The TCM I procured came from a donor 03 Hemi RAM.

It requires a strong TC and it will need to re-learn the pressures of the CRD.

To do that quickly, take it on the freeway ramps every chance you get. The more you drive, the quicker it learns the proper shift points.

It shifts quickly and reaches final gear at 47mph..... kind of makes the CRD feel like an italian sports car.

What I don't particarly like about it is that it revs past 2000 rpms from 1st to 2nd.

I plan on sending the this TCM to Keith at GDE for a review and observation.

Dennis MacGyver · **Posted:** Sun Sep 02, 2012 7:11 pm

ChooChooman74 wrote:

I just bought one off a 2500 ram. Should be in by next week.

Sent from my DROID BIONIC using Tapatalk 2

Do you know the Dodge part number for the one you bought?

racertracer · **Posted:** Sun Sep 02, 2012 8:21 pm

03 DODGE TRANSMISSION COMPUTER UNIT - TCM 56029053AD OEM

Word to the warning:

1. Test drive this TCM at your own risk, because it may destroy a weak Torq Converter.

2. When going through the process of training the shift points, be cautious, don't rev your engine past 3800 rpm.

Dennis MacGyver · **Posted:** Sun Sep 02, 2012 8:43 pm

racertracer wrote:

What I don't particarly like about it is that it revs past 2000 rpms from 1st to 2nd.

I plan on sending the this TCM to Keith at GDE for a review and observation.

Will this TCM eventually "learn" to shift at a lower rpm from 1st to 2nd ?

racertracer · **Posted:** Sun Sep 02, 2012 8:45 pm

Dennis MacGyver wrote:

racertracer wrote:

What I don't particarly like about it is that it revs past 2000 rpms from 1st to 2nd.

I plan on sending the this TCM to Keith at GDE for a review and observation.

Will this TCM eventually "learn" to shift at a lower rpm from 1st to 2nd ?

It hasn't yet, and the reason why I am having Keith look it over.

Maybe Warp2Diesel can answer this question since he's been using it in his CRD for over a year now.

Kgeisler2010 · **Joined:** Sun Sep 04, 2011 9:56 pm **Posts:** 66

striperman36 wrote:

Kgeisler2010 wrote:

i have a tcm from a 03 ram for sale that i had on crd for awhile if ur interested

Why are you selling it?[/q

my torgue coverter was weak and it was disegaging making my engine rev over 4500 rpms. i was going to put it back on once i got the suncoast tc but i traded in the liberty for something a little bigger before i got to that

racertracer · **Posted:** Mon Sep 03, 2012 7:30 pm

I just removed the RAM TCM and reinstalled the OEM TCM.

I can't wait for this thing to learn, 1st to 2nd shift is a killer and life is good again.

Dennis MacGyver · **Posted:** Tue Sep 04, 2012 12:15 am

racertracer wrote:

I just removed the RAM TCM and reinstalled the OEM TCM.

I can't wait for this thing to learn, 1st to 2nd shift is a killer and life is good again.

I've had my Ram TCM a few days now, and yes at first, the shift from 1st to 2nd took place at about 2200 rpm's. But I am a "feather footer" and it seems to be coming down quite a bit. On the last little grade I pulled just tonight, it went from 1st to 2nd at 1800 rpm's. I'll keep an eye on it but it seems the trick is to be consistent with your throttle foot.

If your life dictates city or stop & go driving, and you're constantly going into and out of 2nd gear, the Ram TCM may not be the best for that situation. I know what it's like to have the a**hole behind you riding your a** pushing you to accelerate faster because he/she is in a hurry to get to the next red stop light, not an easy position occupy AND to try and be a feather foot.

But should your driving mostly entail highway driving the shift from 1st to 2nd would only happen in a small amount of time in relation to the time you spend in 4th and 5th gears, hence this is where the Ram TCM will allow you to gain more MPG in the 50 to 63 mph range.

CRD Transmission Modulator Can't Be Fixed

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