Number 1. Its a test feature to make sure that you have a safe driving experience. Brakes that work are always a good thing to have on our fast 3's I'm a little confused. The check rear light comes on every time I start the engine but off once I tap the brakes. Is this because: 1. it is made to test the brakes every time? 2. needs new brake light switch? 3. 3rd light is going bad? (all others have been replaced) Thanks