What does a crankshaft sensor do?
The crankshaft position sensor is one of many sensors used in car engines with Electronic Fuel Injection (EFI) systems. It works using electromagnetic principles. This crankshaft position sensor allows the engine to work at optimal performance. The crankshaft position sensor can determine better fuel usage, proper ignition, and acceleration while monitoring actual engine load and speed.
The Engine Control Module processes the signal generated by this crankshaft sensor with signals from other sensors to produce optimal, effective, and efficient engine work. Therefore, we should check all sensors in the EFI system at a certain period to ensure they all work correctly and always at their best performance.
This article will discuss what does a crankshaft sensor do? Here are three functions of the crankshaft position sensor on an Electronic Fuel Injection engine.
1. Measuring engine rotation speed (engine RPM)
The first function of the crankshaft position sensor is to measure the actual engine speed. The crankshaft position sensor is generally placed on the crankshaft. In most injection cars today, the crankshaft position sensor is placed on the crankshaft gear sprocket on the front engine.
At the rear of the crankshaft gear sprocket, a rotor (a disc with serrations around it) is installed and used to generate a crankshaft position sensor signal.
The signal is generated on the crankshaft position sensor when the teeth of the rotor move and rotate. It is used by the Engine Control Module (ECM) as a signal to determine the engine speed (engine rpm).
2. Reading crankshaft angle and position
The second function of the crankshaft position sensor is to read the angle and rotational position of the crankshaft. This crankshaft position sensor will read the angle and position of the crankshaft for the engine working stroke for each cylinder, especially for cylinder number 1.
Based on the firing order programmed previously into the ECM, the signal from the crankshaft position sensor can be used to determine the angle and position of the crankshaft on each engine cylinder. So that the ECM can know the position of the piston is at Top Dead Centre (TDC) or is at the Bottom Dead Centre (BDC).
In addition, the ECM can also determine the piston stroke based on signals from the crankshaft position sensor, such as during the compression stroke, combustion stroke, exhaust stroke, or intake stroke. That way, the ECM can determine what to do to optimize engine performance effectively and efficiently.
Read also:3. Determining the timing of fuel injection and ignition timing
The last function of the crankshaft position sensor known is to determine the fuel injection and ignition timing for the engine.
Based on the engine rotation speed and the angle and piston position readings generated by the crankshaft position sensor, the ECM can determine the most appropriate time and duration of fuel injection and the ignition timing required by the engine.
When the crankshaft position sensor has a problem, it will generally cause the engine to be difficult to start, stall suddenly, turn on the Check Engine Warning light.