Cadillac Repair: 96 Cadillac Deville Transmission Problem, cadillac deville, transmission problem

Question
i have a 96 cadillac deville, i have first and second gear which shift fine. i also have passing gear. there's no hard shifts, but i can't get third or drive. the vin# is 9

Answer
IS or HAS the CHECK ENGINE light ever illuminated while driving the vehicle and or has any other lights illuminated or any messages from the message display center ?.

What work or diagnostics of ANYKIND WHAT-SO-EVER have been performed on the vehicle trying to fix this problem ?.