The Crank Position Sensor, also known as the Engine Speed Sensor, measures the position or the rotational speed of the crankshaft. It then sends this data to the computer to tell it which cylinder should be fired at the crankshaft’s current position. The crank position sensor is important because it ensures that the engine cylinders are fired in the proper order. It is located on the engine, or somewhere near the crankshaft, usually near the harmonic balancer. The crank position sensor also gathers data regarding the RPMs of the engine. This information is necessary for the computer to select the correct transmission gear based on the speed and load.
If the crank position sensor is malfunctioning, you should be able to tell right away. Generally, if there is a problem with the crank position sensor, the cylinders will misfire. That means the computer is not getting the correct information from the crank position sensor about the position of the piston. If you notice that your vehicle is hesitating when you press on the accelerator, this could also be a sign of an issue with your crank position sensor. The lag in your acceleration means that the sensor is not sending the data to the computer fast enough to fire the correct cylinder. The worst case scenario of crank position sensor failure is if your car just won’t start anymore. While there are a lot of different reasons that your car may not start when you turn the key, one reason is if the crank position sensor has failed. When the sensor fails, the computer notices the malfunction and will turn on the check engine light.