A speed sensor sends information to the car's sensor about how fast the car's engine is spinning at any moment. This is done by the sensor by recording how fast the crankshaft of the vehicle is spinning. To test if the speed sensor of your car is working, you must take your vehicle into the local shop and run a computer diagnostic on it. After you know for sure what is wrong with your vehicle, you can decide which specialty repair shop to reach out to. To buy or take a look at speed sensors, you can find the best of them on eWorldTrade.com. Our business to business ecommerce portal has made it its priority to provide you with high quality products and services at the lowest wholesale rates available. Our manufacturers are some of the best from around the world so you be sure that you are getting the best there is out there. For any inquires, you can directly contact the manufacturer and for feedback or additional help, you always have our customer support available to you.