Modern automobile engineering has made the crankshaft position sensor a vital part of the car’s engine. This small device is instrumental in monitoring the engine’s multiple components through the car’s computerized engine management system. The sensor tracks the speed of crankshaft rotation, monitors the engine valves in relation to the pistons, and inspects the overall engine function.


The crankshaft position sensor is usually often placed on the crankshaft near the main pulley. It passes on information, and as with any other component of the engine, when things begin going south, it needs immediate attention. Ignoring the symptoms of a bad crankshaft position sensor will lead to rapid wear and tear of the various parts of the engine and will quickly lead to engine wear-out. Fortunately, warning signs of a bad crankshaft position sensor are easy for the driver to detect. Read through the following points and watch out for any one of these warning signs.

The Blinking of “Check Engine” Light

The simplest and most obvious sign of a failing crankshaft position sensor is the blinking “check engine” light in your vehicle. Fortunately, this light is programmed to come on well in advance, letting you to take care of the problem before the vehicle is left immobile and you are left stranded. Once the light comes on, be sure to contact your mechanic for a quick look-over or take your car in for servicing.

Ignition Malfunction

When the crankshaft position sensor starts to fail, the signal it transmits to the vehicle’s computer begins to weaken. If left unattended, the signal will switch off completely. This, in turn, causes the vehicle’s spark plugs to die out, killing the engine. If you are having issues starting your car, it could indicate a bad crankshaft position sensor.

Stalling and Backfiring

Another sign of a sensor malfunction is the constant stalling and backfiring of the engine. In such a scenario, the engine is prone to cutting off from time to time, stalling as you drive for a few seconds. Unlike ignition malfunction, the vehicle will probably start, even run for a while, only to shut down somewhere along the way. It goes the same for engine backfiring. If you keep ignoring the warning signs though, the engine may get exhausted and die out.

Engine Vibrations

As stated above, the sensor regulates the crankshaft position. Once the position sensor begins to fail, you’ll notice a considerable increase in engine vibration. This in turn will ruin your mileage as well as engine power.

Other Disruptions in Engine Function

One of the most common effects of crankshaft position sensor failure is seen on the engine function of your car. As the sensor utility deteriorates, it affects regular functions like acceleration, ignition, idling, and speed fluctuations. Each of these functions experience abnormal patterns, resulting from actions not initiated by the driver. If you are experiencing any such car troubles—sudden disruption in acceleration, for example—it might be time to overhaul the crankshaft position sensor.