09 A50 TCM U0101 after full flash

[1fastws6]

Long story short, I've installed a new TCM in my 09 LMM GMC. I used EFI Live to read my original TCM and full flashed that to the new TCM. Now, I'm getting a constant U0101 code and intermittently cannot communicate with the TCM via the tune tool. I've re-flashed with my factory tune file, the original file from the replacement TCM, and a factory tune file from another truck with the same OS as mine from a friend of mine. No joy.

Anyone have any ideas?

[mpdtune]

Long story short, I've installed a new TCM in my 09 LMM GMC. I used EFI Live to read my original TCM and full flashed that to the new TCM. Now, I'm getting a constant U0101 code and intermittently cannot communicate with the TCM via the tune tool. I've re-flashed with my factory tune file, the original file from the replacement TCM, and a factory tune file from another truck with the same OS as mine from a friend of mine. No joy.

Anyone have any ideas?

You need to flash the TCM with a dealer scan tool first. The replacement TCMs are often different hardware than what was originally in the truck, especially with the A50s. This will load the correct base file from GM to start with.

[1fastws6]

Thanks for the reply! I was hoping to bypass the dealer, but it sounds like that is my next destination. Thanks for pointing me in the right direction.

[killerbee]

Please update your experience/findings. Lots of issues with TCM's that are a big mystery.

[1fastws6]

Good News! Took the truck to a dealer yesterday. They programmed the TCM with their scan tool (Tech2?). All's good now, and I can read and write to the TCM just fine. The good take away here is that I didn't brick the TCM by trying to write to it before GM programmed it.

Just for informational purposes, it would appear that my TCM failure was at least partially temperature dependent. The failed TCM would work fine until engine temperature warmed close to operating temp. Sitting still also seemed to make it worse. This makes me believe that ambient engine bay temperature was at least partially responsible for the failure.

Also, for anyone with similar issues, the TCM is available from amazon for just north of $250, and my dealer programmed the TCM for $125. Just over $375 to get back up and running.

[RedmondLBZ]

I have a 2006 lbz I had EFI Live programmed into the truck I loaded my stock file onto my truck. After I did so u0101 DTC came on, if I reflash my truck will it go out or what are the steps to take to see if it's in the wiring or my TCM itself?

[rcr1978]

That's weird I went through this last year with good luck on a 2011 TCM replacement. Must have got lucky;)