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Sensor failure in a vehicle can be a very serious issue, depending on the corresponding component the sensor is installed to monitor. The crankshaft position sensor monitors the crankshaft’s performance and operation and reports to the ECU or PCM, depending on the vehicle’s configuration.
When this sensor fails, it may send wrong or NO signals to the ECU, which could affect how the engine runs.
Hence, it is important to know these crankshaft position sensor symptoms that are most likely to occur when the sensor starts failing or has failed completely. This sensor can be replaced for less than $200 (parts and labor cost).
What is the Function of Crankshaft Position Sensor?
The crankshaft itself is one of the most important parts of the engine; it converts the linear movements of the pistons – the pistons connect to the crankshaft using connecting rods – to rotatory motion that moves the camshaft and other important parts of the engine so that the vehicle can move.
The crankshaft position sensor, or CKP sensor for short, is an electrical sensor installed around the shaft to monitor the position and movements of the crankshaft. This sensor reads the movements of the toothed/notched wheel on the crankshaft or harmonic balancer and sends signals to the ECU or PCM.
While the exact location of the CKP sensor may vary from vehicle to vehicle, it is usually installed around the crankshaft – at the front bottom side of the engine.
The ECU or PCM utilizes signals from the CKP sensor to determine the engine’s spark timing or injector synchronization. The ECU/PCM may use CKP sensor signals for other functions as needed.
When the CKP sensor fails, it implies that the PCM or ECU won’t receive signals as per how the crankshaft is working, and as such, the PCM may not accurately time the injector synchronization and spark ignition required for combustion to occur seamlessly.
Crankshaft Position Sensor Symptoms
1. Intermittent Engine Stalling
If the sensor fails while you’re still driving, it will cut off communication between the crankshaft and the ECU, which could cause the engine to stall – a situation whereby the engine suddenly goes off while you’re yet driving.
There are quite many factors that can cause engine stalling, and a bad CKP sensor is one of them.
2. Hard Starting
The crankshaft is one of the foremost components that gets triggered when you turn the car key; as the crankshaft activates, it moves the camshaft and other engine components, while the CKP sensor notifies the ECU/PCM simultaneously to optimize the combustion process so the car can drive.
When the CKP sensor cannot communicate with the ECU, the ECU may not allow the combustion process to continue, which could make your car not start.
If your car suddenly begins hard starting, or won’t start at all, maybe you should have the CKP sensor checked; notwithstanding, there are other things that may have caused the issue.
3. Misfiring and Shuddering
Another sign you may experience when the CKP sensor goes bad is engine misfiring and shuddering. This is a situation whereby the engine shakes or vibrates even though you’re driving on a smooth, even road.
Misfiring occurs when the cylinders are unfired, or combustion does not occur as needed.
4. The Check Engine Light Comes On
Yeah, there are several issues that can trigger the check engine light to illuminate, and a faulty CKP sensor is just one of them.
When you see that the check engine icon is turned on, have the engine checked – preferably, troubleshoot the engine to find the DTC that caused the icon to come on.
5. Reduced Fuel Economy
Although not in all cases, but this has happened to some people that had a failed CKP sensor.
The reduced fuel economy could result from the fuel injectors not supplying the right amount of fuel (gas) into the combustion chamber due to erratic readings from the ECU, which acted in response to the no/wrong signals from the CKP sensor.
6. Uneven Acceleration and Rough Idling
Uneven acceleration may occur as a result of the misfiring engine. You’d notice that your car accelerates or decelerates even when you don’t initiate the action; the vehicle just can’t maintain a particular speed flow.
Also, you’d notice that your car idles rough when you put it in Park or Neutral gear.
Crankshaft Position Sensor Replacement Cost
Of course, the crankshaft position sensor can be replaced when it goes bad. The average cost of replacing the CKP sensor stands between $150 and $200, depending on your location and the workshop where you went to get it done.
It is important that you fix the sensor as soon as possible to mitigate the chances of facing costlier repairs that may occur due to the erratic signals the faulty sensor is sending to the ECU/PCM. The average time it takes to replace this sensor is roughly 4 hours.
Frequently Asked Questions
Can You Drive With A Messed Up Crankshaft Sensor?
Depending on how “messed up” the sensor is, you may still be able to drive your car. However, if the sensor has died completely, the ECU/PCM may not allow the car to start, which means you cannot drive the vehicle.
Can I Replace The Crankshaft Sensor Myself?
Well, there are so many DIY tutorials on the internet on how to fix and replace different automobile components, but some of these tutorials require you have at least background knowledge of certain professions or disciplines. If you’re not conversant with automobile electrical connections, it’s not advisable to attempt replacing the CKP sensor yourself; have a professional do it for you.
What Is The Most Common Problem With Crankshaft Sensors?
Misfiring, stalling, and hard starting are the common signs that depict you may have a failing CKP sensor in your vehicle. These actions happen because the sensor doesn’t provide the ECU with accurate information about the piston/crankshaft position, which could lead to the misfiring of one or more of the engine cylinders.
These crankshaft position sensor symptoms are the commonest you’d experience regardless of your car model and make.
When you start noticing any of these, it is important that you act fast to replace the sensor or any other component that is causing the symptoms. A good CKP sensor plays an important role in making the engine run efficiently.