I've been having this issue for months but never bothered to post about it. I'm guessing mine is loose from when i got my new tranny (which is already f-ed up) I've wondered about that butt6on before, i always thought it would lock the tranny so it couldn't be shifted (like a kid proof type thing) it really should be the 'tranny unlock button"
So do i press it and just shift and drive on or do i need to press the button again?
yay and i thought the only temp fix was starting the car holding my breath and telling my car "good girl" when it shifts and revving it and saying "come on girl" till it shifts.