I have a 2005 Mustang Coupe with an automatic trans and during the winter the speedometer acts up. It will register way up in speed (60-100mph)when you are only going 20 or 30 mph. It usually starts to work correctly after the weather warms up, however today it is warm but the speedometer was reading over 100mph when I was going 20 mph. Has anyone out there experienced this problem and if so what was done to correct it?

 

bad speed sensor. Good luck...

 

Thanks for the information. It appears that I would need to drop the tranny down a little to get to the sensor, since there is not much room around it.