I was getting the warning light off and on in my 06 RL (Tech). I tried a few things but what turned out to work was replacing the Brake light warning switch under dash at pedal. Been about 6 months now and so happy damn light is gone. Took about 10 mins to fix.

Video here "2005 Acura RL Sometimes Won't Come Out of Park"

Part from Amazon: Wells SW6271 Brake Light Switch