When the key is in "on" position and the engine is running, I can't shift out from park. When the key is in "accessories", I can shift to all other gears from park. If I turn the key to "accessories", I can start the engine and shift to any gear. . But the second I put it into park, It's stuck there. I checked the brake lights.. all OK.
Any help would be very appreciated.

 

I would suspect the brake interlock switch is either bad or not getting any power to it from the brake circuit.