Most autozone type scanners are only gonna pull engine codes, if your luck there is a P700 that tells you there is a tranny code but not what the code actually is.

Those trannies are very reliable, one of the most common problems I have seen is the filter in the pan seperating plastic from metal at the seam and then it sucks air and does all kinds of weird stuff. This problem can be magnified if the fluid is even a tiny bit low and covered up slightly if the fluid is slightly high, THAT IS NOT THE SOLUTION! But it can be a helpful diagnostic tool. Even if the tranny is actually toast they are very cheap to buy good low mile used ones because the engine is usually condemned due to timing chain noise nobody wants or knows how to fix.