I just had this issue, same as the other posters. 08 MDX Tech has 63k. No prior trans issues (coils, but that is OT for this thread). There was "indecision" at about 40 mph with the truck being driven gently. One hill nearby would show this indecision well, with odd shifting up hill and "grabbing" gears downhill. This is mama's car, so she'd often tell me "it doesn't feel right". We've had manual trans cars for the last 10 years, so I had no comparisons.
While driving at 30 mph very gently, the Satnav goes off and tosses P0847. I get to the dealer next day, who diagnoses it as "replace 3rd gear pressure switch". After $170.00 non powertrain warranty dollars, I'm on my way. Apparently a switch attached to the powertrain is not part of the powertrain. (Acura's idea of warranty is much different than BMW's idea of warranty-also OT for this thread).
The trans now shifts cleanly. I think it may also have been reset or reprogrammed, as it now holds high gear longer than before...this is not a problem, just an observation. The shift points and feel are different now other than just the 3rd gear thing.
I hope this isn't an ongoing thing. I dread my dealership and have a good independent who knows Honda, but some things you still need the stealership for.