You are driving, and suddenly your car starts acting weird. The engine may shake or stop, or the car won’t start at all. This happened to me once, and it was all because of a bad crankshaft position sensor. The best part? I fixed it myself by resetting it. Yes, you can do it too. In this article, I will show you the full and simple way to reset the crankshaft position sensor, step by step, using very easy methods even if you are not a mechanic.
Understand What the Crankshaft Position Sensor Does
The crankshaft position sensor is a very small part of your car, but it plays a big role. It helps the car’s computer know exactly where the crankshaft is. The crankshaft is what moves the pistons inside the engine.
When the sensor works well, your car knows when to send fuel, when to fire the spark plug, and when to start running the engine. Without this sensor, the engine does not know how to start or run correctly.
When the crankshaft position sensor goes bad or starts giving wrong signals, your car will show signs. These can be rough idling, engine stalling, poor acceleration, and sometimes the car will not start at all.
A bad sensor can also turn on the check engine light. In some cars, the engine may even stop in the middle of driving, which can be very dangerous.
Before you reset the sensor, it is good to know why it needs a reset. Sometimes, the sensor is not broken, but the car’s computer has saved bad data. That data needs to be cleared. A reset helps the car forget that bad information and learn the right position again.
Resetting the crankshaft position sensor is not very hard. Many people think they need to go to a car shop, but you can do it at home with simple tools. Sometimes, you do not even need tools at all. You just need to follow the right steps, and the car will do the rest. This is great if you want to save time and money.
You also do not need to be an expert. If you can follow instructions and be patient, you can reset it yourself. It can take around 10 to 30 minutes, depending on your car and the type of sensor it has. But the result is a smoother engine and no more strange behavior from your car.
- The sensor tracks crankshaft position
- Helps engine know when to fire spark plugs
- Can cause problems if signal is wrong
- A reset clears wrong info from the computer
- Not hard to do and can be done at home
Locate the Crankshaft Position Sensor in Your Car
Finding the crankshaft position sensor is the first thing you need to do before you reset it. Every car is different, but the sensor is mostly found near the bottom of the engine, close to the crankshaft. In most cars, it is near the engine block, close to the transmission or timing cover. It may be behind or below the engine, so sometimes you will need to lift the car or get under it to see it.
You might need a flashlight because it can be in a dark or tight spot. Some sensors are easy to see, especially if you have a front-wheel-drive car. In a rear-wheel-drive car, the engine might be placed differently, so the sensor could be harder to reach.
The crankshaft position sensor usually looks like a small plug with wires going into it. It is attached to the engine with one or two bolts. The wires go back to the car’s computer system. You might see oil or dirt around it, but that is normal.
To help you find it faster, look in your car’s manual. There may be a small diagram showing you where it is. If you do not have the manual, you can also search online for the sensor location in your car model. Just type in your car’s make, model, and year with the words “crankshaft position sensor location.”
When you find the sensor, check its condition. If it looks broken or burned, you may need to replace it instead of resetting it. But if it looks fine, you can move to the reset steps.
Some cars also have a crankshaft relearn process that happens through the car computer. Knowing where the sensor is helps you reset it if you need to unplug it or clean it.
Be sure your car is turned off before you touch anything. Also, wait until the engine is cool to avoid burns or injury.
- Found near the crankshaft or transmission
- Usually near engine block or timing cover
- Use flashlight to look clearly
- Check car manual or search online
- Sensor has wires and may be dirty
- Turn off engine and let it cool before working
Disconnect the Battery to Start the Reset Process
Once you find the sensor, one simple way to start the reset is to disconnect the car battery. This is a common way to clear saved memory from the car’s computer, which can help reset the sensor.
First, make sure the engine is off and cool. Then, open the hood and find the battery. You will see two cables connected to the battery: one black (negative) and one red (positive). Use a wrench or pliers to loosen the nut on the black cable. Always remove the black cable first. This is important for safety. After that, you can also remove the red cable.
Now, wait for at least 15 to 30 minutes. This gives the car’s computer time to shut down and forget the saved data, including any wrong readings from the crankshaft position sensor.
While waiting, you can also take this time to check the sensor and wires for any damage. If everything looks good, you can continue. Some people like to press the horn or turn on the headlights after disconnecting the battery. This helps drain extra power and make sure everything is reset.
After the wait time, reconnect the battery. Connect the red cable first, then the black one. Make sure the cables are tight and secure. Then start the engine and let it run for a few minutes. Watch how the engine acts. If the crankshaft position sensor was only having a memory problem, this may fix it.
This is one of the easiest ways to try a reset, and it works for many cars. But if the problem continues, you may need to do more.
- Turn off engine and let it cool
- Disconnect black battery cable first
- Wait 15 to 30 minutes
- Reconnect red, then black cable
- Start engine and check performance
- Helps clear bad memory from computer
Use an OBD2 Scanner to Do a Sensor Relearn
If the battery reset does not work, the next method is using an OBD2 scanner. This tool connects to your car’s computer and helps you send commands or clear codes. It can help with sensor relearn steps for the crankshaft position sensor.
Start by finding the OBD2 port in your car. It is usually under the dashboard, near the steering wheel. Plug the scanner into the port. Turn the key to the ON position, but do not start the engine.
On the scanner screen, go to the engine or powertrain system. Then look for a menu that says “Crankshaft Position Relearn,” “CKP Relearn,” or something similar. Follow the steps shown on the screen. Some scanners will ask you to press the brake, hold the gas pedal, or rev the engine for a few seconds. This lets the computer relearn the correct sensor readings.
This method works well if you just changed the sensor or if the engine had repairs. It also helps after replacing parts like the timing belt, camshaft, or engine control module.
Using an OBD2 scanner is a bit more advanced, but many scanners are easy to use today. Some work with your phone using Bluetooth. Just download the app, connect, and follow the steps.
Make sure the battery is fully charged before doing a relearn. If the battery is low, the computer may not save the new settings. After you finish, drive the car for 10 to 15 minutes to help the car adjust.
- Find OBD2 port and connect scanner
- Turn key to ON, not start
- Choose crankshaft relearn from menu
- Follow all on-screen instructions
- Works best after sensor replacement
- Drive car after relearn to finish process
Remove and Clean the Sensor for Better Results
Sometimes, the crankshaft position sensor just needs a good cleaning. Dirt, oil, or debris can make it give wrong signals. Removing and cleaning the sensor can help fix this without buying a new one.
To do this, first make sure the engine is off and cool. Then, use a wrench or screwdriver to remove the bolts holding the sensor. Be gentle and pull it out slowly. The sensor may be stuck if it’s been there a long time, but don’t force it.
After you take it out, look at the tip of the sensor. If you see black oil or metal dust, clean it carefully. Use a soft cloth and a little brake cleaner or electronic cleaner spray. Do not use water. Make sure to clean the sensor’s body and connector too.
Also, check the hole where the sensor goes. If it is full of dirt or metal pieces, clean that area too. Make sure everything is dry before you put the sensor back.
Place the sensor back in its spot and tighten the bolts. Reconnect any wires or plugs. Start the engine and see if it runs better. A clean sensor gives a better signal and helps the computer work properly.
This is a low-cost fix and often works if the sensor is just dirty.
- Turn off engine and wait for cool
- Remove sensor using tools
- Clean gently with brake or electronic cleaner
- Dry fully before placing back
- Check sensor hole for dirt or dust
- Reinstall and test engine
Drive the Car to Let the Sensor Adjust Naturally
After resetting or cleaning the sensor, the car may still need some time to adjust. This is called the relearn period. During this time, the car’s computer watches how the engine runs and slowly updates its data about the crankshaft position.
To help this process, drive the car like normal for at least 15 to 30 minutes. Try to drive in different conditions—slow, fast, uphill, and downhill. Do not drive too hard. Let the car warm up and cool down. This gives the computer a chance to learn new signals from the sensor.
Some cars relearn faster than others. If you notice that the engine still runs rough at first, don’t worry. It may take a few drives for things to smooth out. Keep an eye on the dashboard. If the check engine light stays off and the engine feels smoother, the reset worked.
If the engine is still acting strange after several drives, you may need to scan for trouble codes again or check the sensor.
This step is very important and helps your car return to its normal performance.
- Drive normally for 15 to 30 minutes
- Try different speeds and road types
- Helps car computer relearn sensor info
- Watch for smooth engine and no warning lights
- Takes time for full adjustment
Final Thoughts
Resetting the crankshaft position sensor is not hard when you know the right way. Whether you disconnect the battery, clean the sensor, or use a scanner, you can do it by yourself. These steps save money and give you more control over your car. If your car was shaking, stalling, or refusing to start, this reset might be the answer. Just take your time and follow each part with care. Soon, your car will feel smooth again and ready to go.
| Task | Tool Needed | Time Required | Good For | Notes |
|---|---|---|---|---|
| Locate Sensor | Flashlight, Manual | 10 min | Start of process | Check wires for damage |
| Disconnect Battery | Wrench | 30 min | Clear computer memory | Always remove black cable first |
| Use OBD2 Scanner | OBD2 Tool, Phone | 20 min | Sensor relearn after repair | Follow screen steps carefully |
| Remove and Clean Sensor | Cleaner, Cloth | 25 min | Dirty or weak sensor signal | Let sensor dry before reuse |
| Drive to Relearn | No tools needed | 30 min | Final adjust after reset | Try normal and mixed driving |
Frequently Asked Questions (FAQs)
Is it safe to reset the crankshaft position sensor yourself?
Yes, it is safe to reset the crankshaft position sensor by yourself if you follow the right steps. Make sure the engine is cool before you start, and always disconnect the battery before touching the sensor or any wires. Use simple tools like a wrench or scanner. If you are careful and patient, you can do it safely at home without causing any damage to your engine.
Can I reset the crankshaft sensor without a scanner?
Yes, you can reset it without a scanner by disconnecting the car battery for about 15 to 30 minutes. This clears the memory from the engine computer, which can remove bad sensor data. After reconnecting the battery, the engine may relearn the sensor on its own during driving. This method is easy and does not need special tools.
Do I need to replace the crankshaft sensor after every error code?
No, you do not always need to replace the sensor when you see an error code. Sometimes, the code appears because of a dirty sensor or a false signal. Resetting the sensor or cleaning it can often fix the problem. Only replace the sensor if it is damaged or keeps failing after resets.
Is it okay to drive with a bad crankshaft sensor?
It is not a good idea to drive with a bad crankshaft sensor. The engine may stop while driving, or the car may run very rough. This can be dangerous, especially on highways. Also, it can damage other engine parts. It is better to fix or reset the sensor as soon as you notice the problem.
Can a crankshaft sensor cause the car not to start?
Yes, if the crankshaft sensor is bad, it can stop the car from starting. The engine computer needs this sensor to know when to send fuel and spark. Without the right signal, the engine cannot run, and the car will not start. Resetting or replacing the sensor usually fixes this problem.
Do I need to disconnect both battery cables to reset the sensor?
It is best to disconnect both cables for a full reset. Start with the black (negative) cable, then the red (positive). Wait 15 to 30 minutes before connecting them back. This helps the car computer shut down fully and remove old data, which helps in resetting the crankshaft sensor.
Can cleaning the sensor fix the problem?
Yes, cleaning the sensor can fix the problem if it is dirty or covered with oil. Dirt or metal dust can block the sensor from sending the right signals. Using brake cleaner or electronic cleaner can remove the dirt. Just be sure to dry it well before putting it back.
Is it hard to find the crankshaft sensor in my car?
It depends on the car, but in most cases, it is not very hard. The sensor is usually near the crankshaft, engine block, or transmission. You may need a flashlight and the car manual to help you find it. Some sensors are easy to reach, while others may take more time.