Just the Facts: Vehicle Speed Sensors What does a Vehicle Speed Sensor do? The Vehicle Speed sensor or VSS measures transmission/ transaxle output or wheel speed. The ECM uses this information to modify engine functions such as ignition timing, AF ratio, transmission shift points, and to initiate diagnostic routines. Where are these sensors located? The Vehicle Speed sensor is typically located at the transmission or transaxle. Will a malfunctioning Vehicle Speed Sensor illuminate the check engine light or affect vehicle operation? Yes, a faulty sensor can illuminate the MIL, and may cause numerous and varying drivability problems due to the number of tasks the sensor output is involved in. What are the common causes of failure? In addition to wear, these sensors may have metal contamination, gear damage, or exposure to water intrusion depending where the connector is located. How to determine if these sensors are malfunctioning. The PCM monitors the VSS for component malfunctions as well as circuit problems. The diagnostic codes range between P0500 and P0503. The VSS can be checked with a scan tool or undergo a resistance check. What makes BWD Vehicle Speed Sensors the best. As a basic manufacturer, BWD has complete control of the manufacturing process from componentry to finished product for a trouble-free product 100% environmental, endurance and end-of-line testing for signal amplitude and polarity ensures consistent product reliability and performance View our 21st Century Tune-Up® video video Back to Just the Facts