speedometer fluxuration on 1993 Acura Vigor

Sometimes while driving the speedometer will show 40 mph when driving 30mph?

by in Marrero, LA on April 08, 2011
Get Your Car Fixed at a RepairPal Certified Shop.
We certify shops based on expertise, quality work, and verified customer reviews
1 answer
ANSWER by , April 08, 2011
It's funny I verify speedometer operation on customer's cars using my Garmin GPS system its pretty accurate. Usually speedometers read slightly over the speed you are doing. A professional grade scan tool reads live sensor data which would verify the operation of the engine/transmission Vehicle Speed Sensor (VSS) but the VSS is an a/c signal generator it would fail at all speeds. That would leave the speedometer head as being the problem.