Your car's warning lights can let you know when something needs immediate attention, and a circle with an exclamation mark is ...

causing this warning light (or one saying "Parking Brake") to glow. A more troubling culprit could be worn brake pads, low brake fluid levels, or a problem with the anti-lock braking system (ABS).

This causes the brake pads to press inward against the rotors ... There is also a parking brake warning light that lets you know if the parking brake is engaged. Applying the parking brake ...