I finally took the ride to the dealer and they diagnosed that I need a new TOD module and front and rear speed sensors. I'm just curious if it's common to have all three of these things go bad at the same time. Are they all part of the same system? Or does it just sound like a con? Total cost will be $1000 plus labor. I asked, and they absolutely won't use reconditioned/refurbished parts. Are these things I absolutely need?