So hooked up the scan tool and the aux trans pump works, but it sounds dry. trans fluid is full any idea on what would cause that? Would that cause any other problems? and the temp sensors for the tcm and the transmission fluid both read -40 for some reason.

 

Not sure why those temp. sensors would read -40. The TCM reads those temperatures, so hopefully it's not a bad TCM.
Were you were able to properly plug in the two connectors?
About the Aux Fluid pump, when was the last time you replaced both the main trans. fluid and aux fluid pump filters? There's a chance the filter is restricted or has been dislodged. If the upper seal on the aux filter tube is bad, it could be sucking up some air instead of all fluid.

 

.
Fast idle could be something as simple as the throttle body is dirty and sticking open?
Did you just purchase the vehicle? It is rare that a transmission just dies without some warning signs.
Maybe some background data that includes mileage / past service history etc would help.
My 09 at 233k is still doing OK it has had its share of issues but nothing major that I have not been able to repair so far (knock on wood)

 

I got the bottom connector in no problem the top one seems like it needs to go another quarter turn but it wont move and I don't want to put a wrench on it. The fluids and filters were changed about 5000 miles ago. Going to drop the pan today and check that filter.

 

Bought the vehicle about a year and a half ago. haven't had any major issues till now. if i can get this problem fixed then i need to fix my oil leak problem on the engine. i am also having the issue of low engine oil pressure readings so i need to look into that screen that might need changed for the sensor. The idle issue isn't just fast idle. it will idle fine for 5 min or so then just go to 100% and stay there. Some times it does it right from the start.

 

Not sure how many miles on the transmission that is in there?
https://www.searchautoparts.com/moto...d-transmission

 

Not sure if its been changed. I bought the Tahoe used. 250000 on the odometer.

 

OK then yes at 250k it could be the transmission especially if it had never had a fluid change in 245k and you changed it you probably inadvertently killed it.
If this were mine I would pull the transmission pan plug and drain the fluid then screen the fluid through a filter and see what I find. If you find lots of metal particles then pull the pan itself and you may have a hand full mf metal pieces inside. Hope not, but that is the most likely outcome.
The 2ML70 is a good transmission based upon HD design from a bus transmission but if it is not serviced properly it will fail just like all others out there.

 

Pulled the pan. The filter is still in place and fluid looks good. I remember when I changed the filter there were fine metal particles in the bottom of the pan but haven't had problems till this one. Wouldn't it show symptoms right away if it was an issue? And thinking about it it might have been 10000 miles ago I think I changed the engine oil twice before this. if i remember correctly. anything else i can check or test to see if it is the whole thing? The engine sounds like it has a slight load on it when I put it into gear but it doesn't move. Sensor some where? Thanks for the help from everyone so far. Hard to find direction on what to look for when the dealership says its shot because the transmission "makes noise when we move it".

 

Welll..... Shoot.