2009 Tahoe transmission codes

[Pfrantz]

I have had the TCM reflashed at the dealer which solve many of my shifting issues I had. But did notice that shifting from 2-3 it would slightly hang up at about 3000 rpm before shifting on light acceleration. Today while slowing down Under 10 MPH I heard a loud rubbing vibration sound. Then notice the transmission was taking a while to accelerate and a check engine light came on. The transmission would not shift to 3rd and I was running 55MPH holding 2500 RPM. When I checked the codes I had two, one for P0700 and P0797. I think I need to change my TCM but I am not sure if this is the only issue.

 

[swathdiver]

I have had the TCM reflashed at the dealer which solve many of my shifting issues I had. But did notice that shifting from 2-3 it would slightly hang up at about 3000 rpm before shifting on light acceleration. Today while slowing down Under 10 MPH I heard a loud rubbing vibration sound. Then notice the transmission was taking a while to accelerate and a check engine light came on. The transmission would not shift to 3rd and I was running 55MPH holding 2500 RPM. When I checked the codes I had two, one for P0700 and P0797. I think I need to change my TCM but I am not sure if this is the only issue.

How many miles are on the unit and how many miles are on the fluid? What color is the fluid presently?

If it's just a P0797 and the fluid looks good, you might get away with rebuilding the solenoids and performing a Service Learn Adapts.

This exact thing and codes happened to our 2012 and the transmission was toast. Fluid turned black and metal went through the trans and converter.

GM Goodwrench Remans are on national backorder. A company called Teal Automotive in Indiana shipped a reman 6L80 and torque converter down to the dealership doing the work and it arrived today after a couple weeks. The truck has an aftermarket warranty that GM dealers offer with their used cars and they use Teal to get their transmissions from apparently.

Anyhow, I hope yours just needs rebuilding. My other daughter's Impala had a P0796, same thing but stuck on, and that transmission was toast as well.

Hopefully these kids learn to change their fluid every 40K miles like their dear old Dad had been telling them! It's not only cost them money, it's cost my wife and I as well! LOL

 

[Pfrantz]

How many miles are on the unit and how many miles are on the fluid? What color is the fluid presently?

If it's just a P0797 and the fluid looks good, you might get away with rebuilding the solenoids and performing a Service Learn Adapts.

This exact thing and codes happened to our 2012 and the transmission was toast. Fluid turned black and metal went through the trans and converter.

GM Goodwrench Remans are on national backorder. A company called Teal Automotive in Indiana shipped a reman 6L80 and torque converter down to the dealership doing the work and it arrived today after a couple weeks. The truck has an aftermarket warranty that GM dealers offer with their used cars and they use Teal to get their transmissions from apparently.

Anyhow, I hope yours just needs rebuilding. My other daughter's Impala had a P0796, same thing but stuck on, and that transmission was toast as well.

Hopefully these kids learn to change their fluid every 40K miles like their dear old Dad had been telling them! It's not only cost them money, it's cost my wife and I as well! LOL

The nice part is when my friend replaced the transmission a month ago he changed the fluid and filter. But the transmission was from a suburban so I had to a of shifting issues at first. Took it to the dealership and had then reflash the TCM which everything drove amazing except the 2-3 shift would hang up a little. So it has been about two weeks since the flash when all this issue happen. I checked the fluid when I got home and it was still reddish and did not smell burnt. During the 10 mile limo home the trans temp stayed about 190F. If I replace the TCM and have it reflashed will this potentially fix the issue? Are the solenoids part of the TCM that is just under the transmission pan?

 

[Joseph Garcia]

TCM is the Transmission Control Module (computer). The solenoids are electromechanical devices which are controlled by the TCM. They are accessible by removing the transmission's bottom pan.

 

[Pfrantz]

TCM is the Transmission Control Module (computer). The solenoids are electromechanical devices which are controlled by the TCM. They are accessible by removing the transmission's bottom pan.

But if I replaced the TCM, is the TCM and solenoids on the same unit?

 

[swathdiver]

You can either replace the TECHM (correct term for this TCM) or rebuild it. Don't buy a Dorman unit, they have a pretty high failure rate right out of the box.

You might take a shot at replacing the solenoids instead.

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There are several threads on here an on youtube showing you how its done. I would also consult the manual and make sure that code pertains to one of those solenoids and not one in the valve body, I do not remember and cannot look it up right now.

 

[skpyle]

Pfrantz, check out my thread on rebuilding the TECHM. It will show you the guts of what you are interested in:

https://www.tahoeyukonforum.com/thr...-flush-in-2013-escalade-esv-pic-heavy.130110/

Good Luck!