My 96 gmc yukon wont move in revearse or park.
Vehicle did not move for 5 years. I bought fixed the
motor(ecm) was bad so i replaced it.went for a test drive
drove great for 4 miles, than stopped at a stop sign and
when i stepped on the gas to go it would not move. Push
home. Waited till it got cold again started it up put it in grar
and still wont move. So please any asistance will help.