Your speed sensor affects the operation of multiple systems in your car. Not only does it help you stay within the speed limit, but it also helps your car react better and faster to your driving. So don't be reckless when choosing new sensors for your car. Here are some things you should take note of when buying speed sensors:
Types of vehicle speed sensors
There are basically two types of speed sensors, the engine speed sensor and wheel speed sensor. Although both types do the same job (a.k.a. read data and feed it to either the speedometer or anti-lock brake system), the type of speed sensor you need to buy will depend on the symptoms that you notice on your car. Does your car go through intermittent stops without stepping on the breaks? Then that means you need to change your wheel speed sensor. Is your speedometer reading incorrectly? Then a faulty engine speed sensor might be the cause. Before you go to an auto parts center to get a new speed sensor, be sure that you know which of the two types your car needs.
Optical speed sensor vs. Permanent magnet
After identifying which type of speed sensor to replace, another thing to consider when buying a new one is its material. The conventional style of speed sensor makes use of an optical VSS. This optical VSS is made up of a photo cell, LED, and a two-blade mirror reflector to generate electrical signal, which in turn electronically measures speed. This kind of speed sensor is commonly used and is available for almost all makes and models. But because of the optical speed sensor's moving parts, it is more prone to mechanical wear. If you're looking for a speed sensor that's more reliable, installing a permanent magnet speed sensor is a better choice. It detects speed, direction, and position more accurately than an optical sensor, and its non-contact with the target provides enhanced reliability and an extended life.
Tire size can also affect the efficiency of your speed sensors. If you've upgraded to a bigger tire size than your OE tires, it is advised to recalibrate your tires before installing a new speed sensor. The difference in tire sizes may cause the wrong speedometer readings, which can eventually affect your speed sensor signals.