I have a 201 F150 EB 4x4 auto transmission. I bought it new and have 104,000 It recently started having an issue. This issue is only occasional and not a constant issue. I can be driving down the road and wrench lights up on the display and I lose my speedo and odometer. at that point the transmission will not downshift or upshift. If I slow down and stop. The transmission still stays in the same gear I was cruising in. I can stop, put the truck in park, and remove the key. Then I put the key back in and start the truck and everything is ok. I've racked my brain and can't figure this out and out of warranty.

 

output speed sensor, part of the internal transmission leadframe. very common issue on the 6r80 6 speed transmissions.

 

That was it! All fixed...