Hello. I have a '96 4runner, 6 cyl. ,a/t.
Got in this morning, started fine. noticed red "A/T P" light on dash lights up when in Park. Shift in to any other gear light goes out
and nothing engages.
shift to neutral and engage 4Hi, shift back into D and I move.

Any ideas??

 

The light is used to indicate that "Park" is not engaged and usually comes on when the 4wd selector is in N.
So it was acting like your transfer case was in N which disengages the tranny and = no movement.
It is maybe possible that you hit your selector out of 2wd.
Have you turned the vehicle off and tried to duplicate the event?

 

Thank you for pointing out what should have been obvious!!!

 

No problem; The obvious tends to be the most obscure.