Speed Sensor
Since the early days of automobiles, a need to monitor
vehicle speed has evolved. At present the numbers 40 and 75 correspond
to the range of speed limits. Now how you will be able to know if the
vehicle you’re driving is approaching these speed limits? Well, it is
because a speedometer exists. The main purpose of a speedometer is to
allow the driver to accurately view the vehicle speed, possibly to
avoid a speeding ticket. Most of the speedometers operated off the rear
driveline but some used a front wheel as its input.
During those days, speedometers were optional equipments but became an
industry standard. But do you know where a speedometer gets its
reading? The device that measures how fast your fast is running is the
speed sensor. Today’s vehicles make use of this technology not only to
monitor vehicle speed, but also to monitor component position or rate
of speed change on virtually any moving part of a vehicle.
Speed sensors can be mounted on the different parts of the vehicle to
perform different tasks. An engine speed sensor is mounted on the
vehicle’s crankshaft and is usually where the speedometer gets its
data, whereas wheel speed sensors are located individually at each
wheel or axle generating a signal that changes with wheel speed. A
speed sensor signal that suddenly drops off indicates that one or more
wheels would lock up.
It is important that these two speed sensors are always in good working
condition to provide accurate data. If one of them gives the wrong
signal, control functions of the engine ECU and ABS ECU will be largely
compromised. So to have a long-lasting speed sensor, cleaning it every
now and then is necessary. Simply wipe off the grime it has accumulated
with a towel. Or it’s okay to carefully blow-dry it with compressed
air. Anyway, it does not need to be hospital-clean, it just needs to be
free from major debris and metal media.
