How to Reset Camshaft Position Sensor? Detail Guide

After getting the camshaft of a car replaced or repaired, most people don’t bother resetting the camshaft position sensor. As a result, the vehicle keeps halting in the middle of the road or just doesn’t start at all. So, what’s the exact function of this sensor?

It measures the camshaft speed and position to keep it synchronized with the crankshaft. This way, the timing of ignition, air, and fuel delivery matches and keeps the engine functioning. To maintain the optimum performance of your car, you have to know how to reset camshaft position sensor.

And that’s exactly what we are discussing here. Together we will discover why the camshaft position sensor of your car goes bad and how to reset it. Let’s dive right in.

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What Causes a Camshaft Position Sensor to Go Bad?

The cam sensor of your car is a simple electric device made of plastic and metal. It’s connected to the camshaft and is related to the internal wiring harness of your car. If there’s any physical damage to the cam sensor and camshaft or some wiring problem, the device will fail to perform optimally.

Here are a few reasons why your camshaft position sensor might fail-

Wear and Tear

This is probably the most common reason for camshaft position sensor failure.

As you might know, the cam sensor functions as long as the engine and CMP is turned on. So, the camshaft will keep rotating with the engine even when the car is parked.

This continuous movement leads to wear and tear over time. Particularly the metallic parts of the cam sensor are worn out due to corrosion. Moisture, dirt, and oil on the camshaft position sensor also restrict the movement of the camshaft and facilitate corrosion and rust buildup.

When the metallic parts of the camshaft and camshaft position sensor are worn out, these components fail to perform as they should.

Mechanical Damage

As the camshaft and the cam sensor are closely related to the other components of your car engine, any damage to the engine parts will interrupt the cam sensor’s function.

After minor accidents, all the parts might look fine from the outside, but the smallest damage to the internal parts will cause the cam sensor to fail.

Also, such accidents can directly harm the cam sensor causing the sensor wires to tear or come loose. In that case, the check engine light of your car will turn on.

Wiring Problems

Another reason why your cam sensor might go bad is a faulty wiring harness. If the return or ground circuit fails or the voltage is down, the wires might come loose.

Besides, dirt and debris buildup will interrupt the voltage, and all the wires might come off, leaving the wiring harness completely damaged and useless. When this happens, your car will keep stopping as the engine won’t be able to perform for long hours with a bad wiring harness.

Overheating

I know it sounds like a cliche, but overheating is the main cause of many major problems in your car, including camshaft position sensor failure. When you drive the vehicle for hours on a hot summer day, it can severely damage the cam sensor.

Additionally, your car engine produces a lot of heat in general. If the radiator goes bad or the coolant and lubricant stop working, the heat remains inside the engine and spreads through the components. This extra heat will melt or crack the plastic casing on the cam sensor.

On such occasions, your car’s engine might suddenly come to a halt and won’t get started until you fix the melted cam sensor.

Oil Contamination

This one is also connected to accidents or other physical damage to the car components. When the oil pan leaks or the head gasket cracks, the oil reaches the camshaft and cam sensor and interfere with the regular motion of these parts.

Moreover, any oil leak will lower the engine oil level, indirectly affecting the sensor. A lower oil level equals overheating the engine, and the excessive heat might melt the plastic cover of the camshaft position sensor.

This will also damage the camshaft actuators, combustion chamber, and other camshaft parts. And this will eventually turn on the warning light on your dashboard.

Damaged Timing Belt

If your car has a timing belt instead of a timing chain, it might be responsible for a bad camshaft position sensor. This happens when the timing belt is completely destroyed due to a collision or other mechanical damages.

While tearing up, the timing belt might hit the car’s nearby components, including the camshaft and cam sensor. Also, the snapped belt will wrap the crankshaft and damage the wiring harness.

And this will cause malfunction of the camshaft, crankshaft, and the sensors. The other parts will remain damaged even if you change the torn timing belt. So, you have to replace or repair all the related parts to get your car started again.

Misplaced Crankshaft

In some rare cases, your car’s crankshaft starts shifting from its place and eventually moves out of the belt area. It happens when the main thrust bearing gets worn out due to long-term use.

If this movement continues, the metal part of the crankshaft sensor will eventually collide with one part of the cam sensor every time the engine revolves. As a result, the sensor and the crankshaft will wear out, and your car engine might stop working entirely.

How to Reset Camshaft Position Sensor in Car?

Once you’re able to detect a bad camshaft position sensor, you need to replace it as soon as possible to avoid risks of accidents and further damage to the engine.

Luckily, replacing the cam sensor is easy, and you can do it all by yourself if you have some previous experience fixing car parts.

Now, here’s the thing. When the camshaft of your car rotates, the cam sensor detects its speed and position using a magnetic field. This means you can’t actually reset the cam sensor as the process of detection will remain the same.

Instead, after replacing the cam sensor, you need to delete all the previous trouble codes from the sensor and resync it. This way, the new cam sensor will be synced to the PCM or Power Control Module of your car and continue sending the correct data.

So, how to reset or relearn the cam sensor? There are two easy ways to do it—one with a scanner and the other without a scanner. Let’s find out which one works well for you.

How to Reset Camshaft Position Sensor Using a Scanner?

Using a scanner is a more effective way to reset your cam sensor. Most professionals use a high-quality OBD-2 scanner for this job. So, you’ll also need an OBD-2 scanner. Depending on the quality, it will cost you anywhere from $50 to $400.

Got the scanner? Then follow the steps given below-

Step 1: The OBD sensor will have a port for a secure connection. Use the port to connect the scanner to your car’s computer. Then use your key to turn ON the car without starting the engine.
Step 2: From the display of the scanner, choose the vehicle’s make. You can also allow the scanner to function automatically and detect it using the VIN of your car.
Step 3: Now, you have to let the system data load. For this, choose ‘Manual Selection’ from the display. Then select the model year of your car. You can refer to your owner’s manual to find it easily.
Step 4: Click on the option ‘Diagnostics’ and then select ‘Control Unit’. To generate the details of your engine and transmission, select ‘Powertrain’.
Step 5: Click on ‘Engine Control Module’ and select ‘Special Function’. After that, click ‘Cam Crank Relearn’, and it will reset the camshaft position sensor.

How to Reset Camshaft Position Sensor Without Scanner?

This process is more like restarting your phone. It erases the previous codes from the computer memory of the car. Hence, the new cam sensor data can be easily resynced.

Follow the step-by-step process given below to reset the camshaft position sensor.

Step 1: Here, all you have to do is disconnect the battery of your car. For this, take a suitable wrench and remove the negative cable from the battery. Keep it aside and let the car stay in that condition for one hour.

Through this process, the ECU or Engine Control Unit of your car will reset and clear all the trouble codes saved previously for the damaged cam sensor.

Step 2: Next, disconnect the positive battery cable and reconnect both the negative and positive wires simultaneously. Then turn on your car’s headlights and keep it that way for 15 minutes.
Step 3: When you’re done, you have to replace the car’s battery. Connect the positive terminal first and then the negative one. After this, the ECU will take care of the reset or relearn process and sync to the new cam sensor.

Final Words

So, now you know how to reset camshaft position sensor in the easiest ways. You should always take immediate action when the cam sensor of your car goes bad. Replacing the sensor is probably the only solution to ensure optimal engine performance.

After the replacement, use the mentioned methods to reset/relearn the cam sensor. If none of the methods work for your car and it keeps stopping, take the car to an expert to solve this problem as soon as possible.

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