I would like to know why my question has not been answered about my truck.

Is this an automatic or a manual transmission? Do other gears shift with difficulty or take some effort to get into proper gear? There is a pin that pops into position when in park to hold vechicle in place. Breaking this pin would cause this to occur and it is all mechanical so no trouble codes would appear. Check this http://auto.howstuffworks.com/automatic-transmission11.htm