Vehicle speed sensors send electrical pulses to the computer, pulses which are generated through a magnet that spins a sensor coil. When the vehicle's speed increases, the frequency of the pulse also increases. Symptoms of failure include hesitation, surging, improper shifting, loss of cruise control, loss of speedometer. Recommended service is to check connections for proper output signal. Walker Products Vehicle Speed Sensors (VSS) are designed and manufactured to meet or exceed OE Spec, fit, form and function. Walker Products began supplying the fuel system and engine management needs of the automotive industry since 1946. Today, As an ISO 9001: 2015/TS16949 certified company, we continue our commitment to supplying the highest quality products. Fit: Ford F-150 2003-1999, Ford F-150 2008-2005, Ford F-150 Heritage 2004, Ford F-250 1999, Ford GT 2006-2005, Ford Mustang 2014-1999