i have a friend with a 02 TL with about 53K miles on it.
the cars was having trouble going from D to P, it stops at N and would not go to R unless i put it back in D and then go up again, i helped him replace the whole shift assembly along with the shift interlock solenoid and still same thing, then i replaced the neutral safety switch and still same problem,
any help guys?

 

is the brake light switch working?
Does it feel mechanical stuck, or wont engage?

otherwise I would think something is wrong with the 3 micro switches that run the shifter- they are under a plastic plate below the shifter- if evidence of soda spill in the cup holder- lift the middle out of the cup holder- any residue there?
May have dripped right onto the delicate electronic controllers, remove center console for access- a few hours work- switches a reasonably cheap

 

the brake lights do come on and the 3 micro switches came with the shift assembly so they are new also, and yes there was coffee on the old assembly

 

Look for any signs of damage to the shifter cable. Remove it from the trans and see if you still have problems. If not its something in the trans.