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Discussion Starter #1
Welp I knew it was coming as I read about it before. Happened to my wife today while she was out.

Car jerked when shifting into reverse and drive. Would rev up and slowly take off. From what I read it defaults to 3rd gear.

Drove 55 all the way home on the interstate for 15 miles. Checked the codes with my scanner. It shows U0101 which is " failed to communicate with TCM "

I took off the TCM which resides underneath the battery tray and attached to the transmission. Pins look clean and so does the connector. Apparently these heat up plus the added heat of transmission makes them go out.

Ive checked my local salvage yards and craigslist to see if anyone is parting one out. No luck.

There is a Ebay vendor that will repair this one or send you one of theirs for about halkf the cost of new with 1 year warranty. Good reviews.

Just wondering which route to take?
 

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I had mine changed out a few months ago and it sure felt like it was expensive (~$600) from amazon for a little palm sized computer! I think a repaired one is fine. I wish I had that option a few months ago. Good luck.
 

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Discussion Starter #3
I had mine changed out a few months ago and it sure felt like it was expensive (~$600) from amazon for a little palm sized computer! I think a repaired one is fine. I wish I had that option a few months ago. Good luck.
Thanks. The repaired / exchanged one from Ebay will be right at $325 with next day shipping. Im still holding out until tomorrow mid day to see if I can find one locally at the salvage yards. Only thing is that the part numbers need to match exactly.
 

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Discussion Starter #4
Update 11/9/15


Couldnt find one locally since most the salvage yards were too damn lazy to physically go out and see if they had the module I needed. So I purchased a refurbished one from a vendor on ebay. Goes by the name modulerepair.

It wound up costime $325 with express shipping. Plus a $100 core charge w hich I get back once my old one is shipped to them

Talked to the gentleman and he suggested to move the module away from the transmission by using zip ties and mounting on the firewall. Im going to fab up a aluminum bracket and mount it away from the transmission. Into more of open air. Its the heat that kills these things over time.

Once I get it back I will report on if my car works or not plus what I did to relocate the module.
 

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Discussion Starter #5 (Edited)
Got module in . Car is back up and running. Mounted the module on the brake lines on the firewall. Used a piece of rubber on the backside to assure the lines wont be rubbed through. Reason I did this is because it is the heat of the transmission that kills these modules. Car ran 20 miles so far with no issues t all.
 

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@atxjax, OP glad you were able to fix that! How has it been since?? I'm currently experiencing exactly the same issue with the same code. I've looked up the same repairer on eBay, I'll be taking my TCM out tomorrow and take a look of the number. REALLY hoping replacing the TCM will get her back running. Thank you for updating your result!!
 

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Discussion Starter #7
@atxjax , OP glad you were able to fix that! How has it been since?? I'm currently experiencing exactly the same issue with the same code. I've looked up the same repairer on eBay, I'll be taking my TCM out tomorrow and take a look of the number. REALLY hoping replacing the TCM will get her back running. Thank you for updating your result!!

All has been good. No issues whatsoever since I had it replaced and relocated the module on the firewall instead of on top of the hot transmission.
 

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All has been good. No issues whatsoever since I had it replaced and relocated the module on the firewall instead of on top of the hot transmission.
That is wonderful news! :) One last question, I found the same eBay seller modulerepair and they still have remanufactured TCM in stock. The only thing is what they offer is a L34T and mine was a L32E (L32E-18-9E1B is the whole number, I assume yours was very close to mine if not the same). The seller said "Originally L32E is not compatible with L34T, but our TCM's are adapted to fit all the vehicles listed and all the part numbers mentioned." I was wondering if you got a L34T as well.

Thanks again for your reply atxjax!
:D Cheers!
 

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Nevermind, I just got the part from modulerepair and installed it. Works like a charm. Nothing feels better than getting your broken car back on the road! :D :D :D :D
Thanks OP for sharing your story and experience.
I did the same thing you suggested and tied the TCM on the brake lines.

 

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Hi! I just bought a 2008 MS3 and was wondering if I should relocate my TCM before that issue occurs?
 

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My first post. I thought I'd pass along my experience.

Daughter has a 2006 Mazda3, 2.3L Automatic. Out of the blue, the car starts shifting funny and the check engine light come on. I read the codes and there is the code "U0101 Lost Communication with TCM". I have the service manual and dug around there. Also did some Internet searching. That's how I got to this thread. Seeing as the TCM is like $500, I checked a number of the non-TCM replacement possibilities. Swapped some fuses and swapped a relay, checked the continuity from the TCM to the PCM on the CAN bus. All looked fine. On the off chance it was a bad connection, put it all back together and test drove it. It would drive fine for several minutes and then mess up again. It might go back and forth from good to no good several times over the course of a 10 minutes test drive. Looked at TCM's on eBay and some places that claim they repair them. Bought a TCM from a local dealer that has an Internet parts business. Put that in and it fixed it.

Just for my own curiosity, I took the old TCM apart. The entire thing is potted in silicone or something like that. I don't see how anyone can disassemble them. Perhaps a simple repair like a pin repair from the underside is possible, but I'm skeptical.
 

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I'd like to add my experience with this issue as well. Hopefully it help another owner and point them in the right direction.

I have a 2008 Mazda 3 with a little over 70k miles on it. I had the same issues that others have stated:

-CEL light along with the AT light
-Clunky shifting from drive to reverse
-On the freeway/ highway, it would get stuck in 3rd.
-Sometimes I pull over onto the shoulder or street, turn the car off and the problem would go way...but it always came back.

Like others I used a code reader and got code: U0101

I did some research on the series of tubes they call the internets and found this excellent post:

https://www.mazda3club.com/mazda3-m...-mazda3-trans-problem-56278/page3/#post423330

The company others have referenced in this thread as well as the thread that I posted (Module Repair Pro) is based here in Los Angeles, so I was able to remove the TCM module and drive it down to them in person. The repair took less than 24 hours. I've got over 1000 miles post repair and have had no issues. They also replaced that resin backing that others have mentioned with some sort of heat shielding. They also added spacers to the bolt holes to add some distance between the module and the transmission.

Module Repair Pro INC

Lastly, I did not have to remove that one metal bracket piece that covers the module in order to remove the unit. I have rather small hands, so I am sure that helped me. Your experience may vary.
 

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Hello everyone...bought me a 04 mazda 3 2.3l. Well about a month ago it would not shift into 4th gear and halfway through 3rd it would just rev...the at and check engine light would come on. After reading all over the net. I looked at the tcm/pcm mounted next to the battery. It's obvious it's been opened. I opened it myself and the lady owner had written "stupid part" on the inside! So I went to a salvage yard and got another tcm/pcm. I had it reprogrammed. The problem still persists. Only now 3rd gear works till about 4000 rpm then the light comes on and it just revs. Any ideas on this problem? Possibly I bought another bad tcm/pcm? Thanks for any help. I'm still researching this constantly.
 

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Well even though this thread is dead. Id like to let ppl know that I bought 3 different tcms. All needing keys reprogrammed... And im still having problems.... The code on the newest one is . P0762 at shift solenoid... Comes up twice.... So in my case after lots of money down the drain. It was a different problem altogether.... I bought a tcm from a good reputation dealer called flagship one for 230. They program it to your VIN.
 
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