What Happens If You Don’t Relearn Crankshaft Position Sensor?
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The crankshaft is the backbone of the engine. It is the most crucial part of an engine as it converts linear motion to rotational motion. Without a doubt, an engine is useless without a good crankshaft. Even if one has a good crankshaft but sets it up in the wrong position, it is also a crime.
Now the question is, what happens if you don’t relearn crankshaft position sensor. Before we answer that, we need to know what a crankshaft is.

What Is a Crankshaft?
The crankshaft is an integral part of an engine. It is referred to as the backbone of the engine due to its importance. The primary purpose is to turn the linear motion of a piston to rotational motion in the flywheel.
What Is a Crankshaft Position Sensor?
To maintain the integrity of a crankshaft, one needs to know its status. This is where crankshaft position sensors come in.
The crankshaft position sensor is the most crucial sensor used in an engine. It continually takes readings of the rpm and position of the crankshaft. These data are then sent to the Engine Control Unit (ECU)
Its Importance
The ECU needs to know the perfect rpm and position of the crankshaft. Without the data about the position and rpm, the ECU cannot complete the engine’s functions. That is why if the crankshaft position sensor is damaged, which means the whole engine is damaged.
Why Relearn?
The crankshaft position sensor might get damaged while changing or repairing the engine. That is, the sensor might need to be recalibrated or relearned.
The symptoms of a bad or failing crankshaft position sensor can be many things. Issues like a failure in starting the engine or reduced gas mileage are some examples. So, to experience smooth driving, relearning the crankshaft position sensor is a must.
The relearning can be done using an OBD Scanner or Reader. Many think that it is not essential to relearn the crankshaft position sensor. So, the new question what happens if you don’t relearn the crankshaft position sensor?
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What Happens If You Don’t Relearn Crankshaft Position Sensor?
You must know the problems you might face due to a bad or failing crankshaft position sensor. These problems are also the symptoms that the crankshaft position sensor is failing or has been damaged.
Check Engine Lights Up
The ECU remains in constant contact with the crankshaft position sensor. If the ECU doesn’t receive feedback, then the computer receives misinformation about the crankshaft’s speed and position.
Due to this, the engine can’t function efficiently. This, in turn, lights up the Check Engine light. In reality, it is the first symptom of a wrong crankshaft position sensor.
Starting Issues
If the crankshaft position sensor fails, then the ECU will also fail. Due to this, the ECU will have a problem igniting the spark in the combustion chamber.
Thus, starting the engine will be almost impossible. The only way to stop this from occurring is to relearn the crankshaft position sensor. Otherwise, you gave up the thought of starting the engine.
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Intermittent Stalling
Intermittent stalling is the phenomenon of the engine stopping suddenly while running. If the crankshaft sensor isn’t positioned correctly, then it will be a daily occurrence for your vehicle. If you want to drive your vehicle without interruption, it is best to relearn the position.
Uneven Acceleration
As the ECU will not be able to work appropriately, the spark ignition and fuel injection timing of the engine will also malfunction.
Due to this, the speed of the crankshaft might increase or decrease by itself. And if the crankshaft malfunctions, the engine will lose its accuracy, causing it to undergo uneven acceleration. This problem is a life-threatening issue.
Engine Misfires
If the ECU doesn’t send the signal to the spark ignition unit, then the engine will not run. But if the signal is sent in the wrong intervals, then the spark unit will misfire.
This, most of the time causes a misfire in one or more of the cylinder chambers. Though it might not seem that big a problem, it damages the crankshaft over time.
Engine Vibrates
Due to the cylinder’s misfiring, the crankshaft undergoes uneven rotation. This rotation feels forced due to the miss-timed spark ignition and fuel injection.
If the rotation is forced, then the engine feels as if it is vibrating. This is an apparent problem caused by a bad crankshaft position sensor.
Rough Idling
Another problem that arises due to the problem in the crankshaft position is Rough Idling. The bouncing sensation and shaking in the vehicle while the vehicle is idling in a red light or stopped. It gives the feeling that the engine is grinding. It damages the crankshaft and needs to be fixed if the vehicle is to have a long life.
Reduced Gas Mileage
If the ECU cannot get the crankshaft’s perfect rpm and position, then the fuel injection also misfunctions. Due to this, the fuel injectors will not pump gas efficiently. That means the engine will require more gas than required for long and short drives. It isn’t good for both your engine and fuel economy.
Conclusion
When a crankshaft position sensor doesn’t work correctly, the problems may seem irrelevant. However, these problems caused due to the ECU not getting the crankshaft’s proper position are life-threatening for your engine and life. That is why it is essential to relearn the crankshaft position sensor. Otherwise, it is better to get an entirely new engine.
The most economically efficient thing you can do if you face this problem is just relearn the crankshaft position sensor. Hope the article helped you understand what happens if you don’t relearn the crankshaft position sensor.