Speedometer is not working. I changed the VSS. Still Nothing. My SES light is on and the codes that came up were PO502 and PO503, they are both speedometer codes. I checked the plug at the VSS with a test light and it did not light up the bulb. All fuses in the car are good. I am curious if I need to check the plug in with a MULTIMETER if it is low voltage? Any help would be appreciated. I really do not want to take it to the shop and get raped for diagnosing the problem.