. The break light and transmission interlock are usually combined into one unit behind the brake pedal. Not sure if it was that way in the 2000, but it's a relatively easy DIY repair if it is. The part should be less than $20.00, even at a dealer. There's a chance your brake lights are not functioning properly also if the unit is failing. I wouldn't wait too long to fix it. It's only likely to get worse, and then you won't be able to shift at all. There should be a manual override in the console somewhere, if it absolutely wont come out of park.
Bob