Vehicle Speed Sensor: Description and Operation

The VSS is a pulse generator mounted in the transaxle. A reluctor ring rotates near a magnetic pickup which produces a varying voltage signal in the pickup coil. This voltage signal varies in proportion to vehicle speed and is sent to the PCM, where it is converted to mph.

The PCM uses VSS information for fuel economy calculations, cruise control, idle speed control, transaxle shifts, and to control fuel under certain conditions. A faulty VSS may cause various transaxle and engine driveability conditions and will set a PCM DTC. Refer to Transmission/Transaxle for diagnosis.