THE BEECHMONT CREST AUTOMOTIVE LEARNING ZONE
SPEEDOMETER
A speedometer is a type of vehicle instrumentation. The speedometer indicates the traveling speed of the vehicle. There are two types of speedometers: mechanical and electronic.
A mechanical speedometer indicates vehicle speed by reading the speed at which a speedometer cable gear is turning. The speedometer cable gear is driven by a drive gear located on the transmission or transaxle output shaft. The rotating speedometer gear in turn spins a metal speedometer cable, which is connected to the speedometer itself.
An electronic speedometer does not have a mechanical cable and gear mechanism. In vehicles equipped with an electronic speedometer, a vehicle speed sensor located on the transmission or transaxle sends a signal to a control module, which is then converted into a readout on a speedometer display.
