Have you received the recall notice for the underhood wiring harnesses? I had problems some time ago with my ABS and TC lamps going on/off so the dealer changed the LF harness after working on it for a week and the problem went away. A couple of years later, I needed the underhood harnesses changed because all the insulation was falling off. In the process of doing the work the mechanic blew up 2 ABS units. My ABS unit is a newer model, doesn't make that self test sound and reacts far better than the original.