Hello and welocome.
This code is described as "Maximum adapts and long shifts"
Basically the transmission has a late shift that it is trying to compensate for.
It gets to a point where it connot compensate enough to get the correct shift time. youm may not even feel it. It looks for a shift time of less than .65 seconds. Eventually you will notice late shifting.
This can be casued a faulty pressure control solenoid, valve body problem, accumulator problem, or any one of the clutches. All of which are internal to trans.
A fliter and fluid change may help.
would need a Trans. tech to drive it with a scanner on the computer and watch many different parameters to determine where the problem is.
Black fluid is a sure sign of one or more clutches failed.
IF the dealer replaced fluid, it very well can go burnt / black within 16,000 because something has failed.
If there was nothing wrong internally, then the fluid would still look red.
With the fluid being that bad, the quote was probalby because the possible cost of any fialed parts may exceed the cost of a new trans.
When one part fails to cause the fluid to be that bad, it more than likely has affected many other parts.
Maybe got a little confused. Thought you meant the dealer changed it before you got it...
"so if the dealership had replaced the fluid upon thetre inspection there shouldnt have been any reason why the fluid was that dirty or burnt smelling... right? "
Then back to my earlier reponse of the things that can cause this code.
Something has caused the fluid to be black when your hubby changed fluid.
Any one of the things in precious post can cause this except the pressure control valve solenoid. Again, a scan tool looking at data would be needed.
I might suggest going to a GM dealer and having them run a diagnostic on it before have the trans. shop just put in a new trans.
The GM tech will know exactly what data to look at be able to determine if this trans. is repairable or needs replacement.
Good luck. Get the trans thoroughly checked out buy a trained transmission Tech.