I have a 2000 acura RL. My battery died and I went thru hell to get it started again. When I finally got the car started,I could not shift from park into drive while pressing the brake pedaluntil i pressed the lockshift mechanism located on the right side of the gearshift guide. I know I neednew brakes in the front,maybe even new rotors!Why is this happening? Any help or suggestions would be greatly appreciated!

wow old post.sorry this took so long to get back to you.

the brake light switch also tells the ECM to unlock the shifter.

it is very common for that switch to go bad.

it can also leave your brake lights on when you NOT stepping on the brakes. causing a battery drain.

I concur... It can also make your brake lights NOT work.
This is the most common cause for this kind of problem.
Have someone step on your break pedal while you stand behind and see if the lights come on. if not replace that break switch.