Hi All,
I was recently driving my 09 Tahoe hybrid and it just stopped moving in forward or reverse. I had the truck towed to the nearest chevy dealership and they replaced the auxiliary trans pump and the exterior control module attempting to resolve the issue, but it did not fix it. The truck is showing 8 codes and they recommended to replace the transmission to the tune of 5600 dollars. The transmission would come with a 3yr/100k warranty and the transmission alone would cost 4000. I have looked online and found a few used transmissions, but I have lots of questions. Can I use a "2x4" transmission for my 4x4 Tahoe? I spoke with the dealership about it and they said their is only one type of transmission for this truck and I need the M99 model (basically there is no difference between the 2x4 and 4x4 models except I have a transfer case in my truck). My next question is does the internal module have to be swamped or can the used module be programed to my vehicle? Any advice or if someone has a used transmission for sale for a decent price, please let me know. Thanks in advance.

 

What are the codes? There have been wiring issues that may lead to a very expensive fix when it is a nicked wire.


You can convert the 2WD to 4, need to swap tail end parts. You can swap the internal computer as well.


Do the homework on those codes FIRST.

 

So they replaced two expensive parts and it didn't resolve the issue? I would be skeptical of their ability to accurately diagnose the problem. Sure replacing the transmission will resolve the problem and make you happy but is it indeed necessary?

I would suspect that if the transmission was damaged beyond repair, there would be bits of metal, Clutches, Etc. in the roasted transmission fluid...sort of hard to miss.

As Hillbilly said, the truth is in the codes and the ability of the technician to interpret those codes.

I recently had a similar issue, multiple transmission codes & stuck in limp mode(it still drove but barely), they accurately diagnosed the issue & replaced the internal transmission computer and valve body(mine is also an 09).

I am fortunate to have access to a Chevy dealer with a hybrid/electric expert technician & a lot of Hybrid/electric cars to service, they even service those VIA Motors cars.

I would find a competent hybrid technician and get a second opinion , may save you thousands of dollars.