My check engine came on, giving the code for faulty EGR valve. After disconnection, of the OBDII, my speedometer quit working. I then got a code for a vehicle speed sensor. I replaced both the EGR valve and the speed sensor. The speedo still does not work, however when I plug the OBDII into the recepticle as if testing, the speedometer operates. What could be going wrong?
Mar 13, 2010 at 5:16 PM