The crankshaft position sensor is crucial for the function of important car engine parts. In many modern vehicles, engines will not start without adequately working crankshaft sensors. Crankshaft’s main function is to monitor the rotational speed and position of the engine. This information is transferred to the Engine Control Unit (ECU) to manage fuel injection and regulate ignition. In this guide, we will provide you with complete information about the crankshaft position sensor and its working in vehicles.
Function of Crankshaft Position Sensor
Crankshaft position sensor functions on the principle of pulse detection and counting. The sensor consists of the following parts: stationary detector, electronic circuit and toothed disc attached with the shaft. When the shaft rotates the toothed disc also moves, every time the tooth passes by a stationary sensor it creates an electric pulse. The crankshaft sensor converts these pulses into rotation speed and forwards the information to the ECU. In a similar manner, the position of the engine can also be obtained by counting the number of pulses.
Types of Crankshaft Position Sensor
The crankshaft system upgrades in modern vehicles as per the technological advancements. The engine crankshaft position sensors can be distinguished on the basis of their working and technology used. We have enlisted some widely used sensors in the cars.
Inductive
The inductive crankshaft uses a magnet to measure rotations. Whenever a toothed disc rotates it creates changes in the magnetic field generating an alternating current and sending it to the ECU. The inductive sensor is located on the engine block or near to the crankshaft and timing belt.
AC Output
The AC output sensor works differently from all the other types of sensors. High frequency current is generated by the onboard controller to excite the coil. The disc attached with the camshaft has a slot in it. When the slot passes the coil it creates inductance and a signal is forwarded to the onboard controller.
Hall Effect
The hall effect type works similar to that of an inductive sensor. It measures the current when the toothed disc passes by the sensor. However, in place of a magnetic field, it sends digital signals (on or off) to the ECU.
Optical Position
The optical position sensor is the latest version of crankshaft sensors. It uses a light-emitting diode (LED) and a photodiode to trace the optical marks on the shaft to measure the speed. These sensors are more accurate and equally effective for petrol and diesel engines.
What if it Malfunction?
The car engine performance is directly affected by the malfunctioning crankshaft sensor. In case of any improper working, inappropriate data will be communicated to the engine control unit. Due to this, the control unit starts depending upon its own memory to cater for changes. This can impact multiple functions of the engine and even cause ignition switch problems. The symptoms of inadequate crankshaft sensors are visible and can be fixed.
Symptoms of Malfunctioning Crankshaft Position Sensor
The crankshaft position sensor is an important part of an engine, any malfunctioning is immediately alarmed by various symptoms. These symptoms range from engine light indication to difficulty in starting a vehicle. See the following common symptoms of a bad crankshaft position sensor.
- Stalling: Car stalling is generally observed when the wiring of the crankshaft is not working properly. The loose or worn-out connections can disconnect the engine with the sensor while driving that causes stalling.
- Starting Issues: The crankshaft sensor is responsible for monitoring speed and other factors prior to starting the car. If it malfunctions, either the vehicle will have intermittent starting issues or will not start at all.
- Engine Light Indication: The engine warning light starts indicating on the dashboard. This refers to different improper functioning under the hood, and the crankshaft is the most common one.
- Misfire: A failing crankshaft cannot detect the correct position of piston which causes a cylinder to misfire.
- Uneven Acceleration: Difference between the speed and fuel injection data restricts the proper fuel supply to the engine. This causes uneven acceleration at higher speed. Also, it is difficult to keep the speed constant at a constant pace.
- Vibration: The engine idling sound changes suddenly when the crankshaft malfunctions. You can observe a grinding or vibrating sound from the engine and a constant decrease in the engine performance.
This was all about the crankshaft position sensor and its importance in the vehicle. Replacing a malfunctioning crankshaft position sensor can cost you anywhere between AED 75 to 275. It is not a serious concern, but the engine may suffer if the problem is left unsolved for too long. If your car has suffered damages that require major repairs, you can buy used car for sale in the UAE instead of spending time and money on fixing it.
FAQs
What causes the crankshaft sensor to go bad?
Wiring harnesses and high temperature are the most common reasons that cause crankshaft failure. Moreover, loose wires, improper voltage or debris can also damage the sensor.
How to check the crankshaft sensor with a multimeter?
You can check the working of the crankshaft position sensor by checking its resistance using a multimeter. Set your multimeter on Ohms setting and set it as per the Ohms resistance of your crankshaft. Generally, it is between 20, 000 to 25, 000 Ohms. Put both the probe leads on the sensor and note the resistance.
Stay tuned to UAE’s best car blog for more information on car sensors.
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