Hello , long time gm owner recently purchased a 2010 expeditionEL (100k miles) . So far I've been real happy with it, except one issue bothers me. Frequently when I am coming to a stop the trans downshift hard from 2 to 1 It can get especially annoying if I get stuck in stop and go traffic . So far I've tried ...
flushed trans by dealer. Original fluid looked ok and did not smell burnt.
left battery cables off to reset adaptive learn trans
drive in tow/haul mode.
nothing seems to effect the issue, any suggestions?
I'm considering a chip / tuner anyone resolved this issue with one? Any recommendations on brands

 

Are you sure it is the transmission? There is a driveshaft bump that plagues the F150 at stopping/starting time, may be similar on the Expedition, I don't know.

 

It's definitely the trans downshift. Rpms jump up when it happens