BMW Speed Sensor

A speed limit is the maximum speed allowed by the law for vehicles on the road. They are usually marked with a traffic sign which often appears near political borders and road intersections, and in some cases, they appear at regular intervals. What is the reason for this? Well, this is to remind drivers that they should stay within the boundaries of the prescribed speed limit to prevent collisions and other adversities that might come their way. Therefore, the speed rate with which vehicles run should be always watched out for. Drivers should be completely aware about the speed rate with which their vehicles are going.

Now, how will you know your vehicle’s speed rate? The device that measures how fast your BMW is running is the BMW speed sensor. Basically, speed sensors are of two types. One is the wheel speed sensor which is employed on vehicles equipped with an anti-lock braking system, commonly known as ABS. The wheel speed sensor measures the rotational speed of the wheel and feeds the data to the processing unit of the ABS. The speed sensor does this by picking up impulses from the wheel’s toothed signal rotor.

The other type of speed sensor is the engine speed sensor. Engine speed sensors are usually made up of a toothed metal disk mounted on the crankshaft and a fixed detector covering a magnetic coil where the current pulses passes through. This type of speed sensors obtains impulses from the toothed signal crankshaft and delivers these impulses to the engine ECU, then calculates the engine speed through the impulses.

The signal from the wheel speed sensor tell the ABS ECU whether the vehicles’ wheel is locking or not while the speed signal delivered by the engine speed sensor are used by the engine ECU in controlling engine timing, fuel delivery and automatic transmission shift points. It is important that these two speed sensors are always in good working condition to provide accurate data. Why? Because if one of them gives the wrong signal, control functions of the engine ECU and ABS ECU will be largely compromised. So if ever you have damaged BMW speed sensors, have it replaced right away.