Hi, I've recently upgraded my front discs to a grooved and drilled one. I've also put on a set of OEM pads. The brake fluid was fully bled and refilled as well. However, the Brake pads warning lights came on. Can this mean faulty sensor? I don't really think its sensor though since it only came on after I changed the discs. Don't really know what's wrong unless Audi A8 doesn't like grooved/drilled discs? Can anyone please advice?