I've Something odd going on with my 95 T100 3.4 automatic.

I had a check engine light came on + My O/D off light was flashing (it was in O/D and that hasn't happened again) and I put an OBD2 reader on it, came up with Shift solenoid, OK well I figured I'd reset and drive until the check engine light came back on just to make sure.

It finally came back on, Seems to come up doing 50-60 MPH, It came back on just after I put cruise control on and then I wanted to see if use cruise control was triggering it.

I disconnected the battery, it went away and it came back on after I braked pretty hard at a changing light.
Here's where It gets weird, I tapped the glass in front on the check engine light to see if maybe the shock of stopping flipped it on.
AND IT TURNED OFF, I tap it again and it turns back on!
I also found out that thumping the dash with my hand does the same thing.

I'm pretty much completely stumped, I did a quick Google search and didn't find anything.

My plan is to take the truck to O'Reillys and hook it up to an OBD2 and see what comes up again, if the solenoid code it still there, I'll probably replace all 3 and see of it makes the check engine like stop coming on.

Any ideas?
It seems like it'd be a loose plug or something like that, I'm assuming the two issues aren't going to be connected but you never know!

 

Bump.