The crankshaft position sensor is one of the most important sensors under the hood of your car. The main function of the crankshaft position sensor of the car is to determine the speed of the reluctor’s ring, which in turn determines the rotational speed of the crankshaft.
This speed of rotation of the crankshaft is also used to determine the spark timing in the cylinder and the amount of fuel injection in the combustion chamber of the car.
In this powerful guide, you will quickly learn the Seven symptoms of bad crankshaft position sensors.
Related Post: Crankshaft Position Sensor: How It Works, & Functions
What Are The Symptoms Of A Bad Crankshaft Position Sensor
The tip of the crankshaft position sensor is located close to the teeth of the reluctor’s ring. The reluctor’s ring has certain missing teeth which reciprocate the reference point.
As the teeth of the reluctor’s ring pass beside the tip of the crankshaft sensor of the car, the crankshaft position sensor of the car generates electrical pulses and sends them forward to the Electronic Control Unit (ECU) of the car.
When there are no teeth of the reluctor ring, there will be no signals forwarded by the crankshaft position sensor. As a result of no signals sent forward by the sensor, there is no spark initiated in the car engine, and there is no fuel injection because of the absence of a .signal from the crankshaft position sensor.
Over time, the crankshaft position sensor gets clogged due to dust and dirt or losses its job, which shows several problems. You should look for the following signs to ensure that your car’s crankshaft position sensor is working perfectly. Below are the Seven symptoms of bad crankshaft sensors.
7 Symptoms Of Bad Crankshaft Position Sensor
1. Lighting Up Of The Check Engine Light
The symptom of a bad crankshaft position sensor is the lighting up of the check engine light on the car dashboard.
If any kind of problem is detected by the computer of the car related to the crankshaft position sensor of the car, the engine light illuminates on the car dashboard to alert the driver of the potential failure of the crankshaft position sensor.
The check engine light could be illuminated for several reasons; you could check the exact problem that is causing the illumination of the check engine light by getting the trouble codes scanned.
2. A Problem In Starting The Car
One of the biggest symptoms related to a bad or faulty crankshaft position sensor is difficulty in starting the car. The crankshaft position sensor of the car is used to monitor the position of the crankshaft along with its speed and other parameters that are essential and play a pivotal role in starting the car.
Hence, if there is some problem with the crankshaft position sensor of the car, your car might have alternative issues while starting the car, or your car might not start at all.
3. Rough Idle
Rough idling is another symptom of a bad crankshaft position sensor. Rough idle is the condition when your car’s engine does not feel smooth. The car RPM goes up and down drastically without any input; it falls to the lowest by itself at one point and jumps up again without depressing the pedal.
A faulty crankshaft position sensor will not send the right signals to the ECU, as a result of these wrong signals sent to the ECU, the ECU adjusts the fuel injection into the combustion chamber according to these readings, which leads to the fluctuation of fuel injection delivery.
Hence, because of these bad fuel injection fluctuations due to the false readings sent by the crankshaft position sensor, rough idling is caused in your car.
4. Misfiring Of The Engine
The misfiring is also a crankshaft position sensor symptom. The misfiring of the car is the condition of the car when you hear or feel a stutter in the car while driving.
The faulty or failing crankshaft position sensor of the car cannot provide the correct information about the position of the piston in the engine to the Electronic Control Unit (ECU) of the car, which causes the cylinder of the car to misfire.
5. Unsteady Acceleration
An unsteady acceleration is also a bad crankshaft sensor symptom. When the crankshaft position sensor of the car gets faulty or bad, the input signal that would be sent forward by the sensor will be false, the car Electronic Control Unit (ECU) uses this data to decide upon the spark timing and the amount and time of the injection of fuel into the car combustion chamber.
When the signals sent forward by the crankshaft position sensor of the car would be faulty, these decisions spark timing, and the fuel injections would also be faulty, which causes unsteady car acceleration.
6. Stalling Of The Car
Another sign that is most common in cars with a bad or faulty crankshaft position sensor is the irregular stalling of the car. If there is an issue with the crankshaft position sensor of the car or with any of the wirings of the crankshaft position sensor, there might be a condition that there would be no signal transferred to the car’s Electronic Control Unit (ECU), which in turn causes the car to stall.
This problem most commonly arises in cars with the crankshaft sensor with bad wiring however, it could also be caused because of the bad crankshaft position sensor.
7. Reduced Gas Mileage
Reduced gas mileage is another symptom of the bad crankshaft position sensor. The crankshaft position sensor helps to inject the amount of fuel into the combustion chamber for a specific time, if the crankshaft position sensor gets damaged, the sensor will deliver the amount of fuel for a long duration in the combustion chamber.
This long duration of fuel delivery uses more gases than needed, which leads to reduced gas mileage. If any of these symptoms mentioned above are observed in your car, you must get your car checked for a faulty crankshaft position sensor.
The following symptoms indicate that your crankshaft position sensor is bad.
• Lighting Up Of The Check Engine Light
• A Problem In Starting The Car
• Rough Idle
• Misfiring Of The Engine
• Unsteady Acceleration
• Stalling Of The Car
• Reduced Gas Mileage
When a crankshaft sensor fails, it will often trigger a diagnostic trouble code (DTC). These codes can be read with a diagnostic scan tool, and they typically fall between P0335 and P0338. In some cases, a crankshaft sensor may simply need to be cleaned or replaced in order to fix the problem.