What a camshaft position sensor does in your engine

A camshaft position sensor tells your engine's computer where the camshaft is at any given moment. The camshaft controls when your engine's intake and exhaust valves open and close. Without accurate position data, your engine cannot time the fuel injection and spark plugs correctly, which means it will run rough, use more fuel, or fail to start.

The sensor itself is a small electronic device mounted near the camshaft or on the cylinder head. As the camshaft rotates, the sensor reads a tone ring or magnetic reluctor wheel and sends a signal to the engine control module. If this sensor fails, your check engine light comes on and your vehicle enters a limp-home mode where performance drops sharply.

Most vehicles have at least one camshaft position sensor. Some engines, especially those with dual overhead cams, have two or more. Advance Auto Parts stocks sensors for most common makes and models, and their staff can help you identify which one your vehicle needs based on your vehicle identification number (VIN).

Key Takeaways

  • A camshaft position sensor reads the camshaft's rotation and sends that data to your engine computer so fuel and spark timing stay correct.
  • When the sensor fails, your check engine light illuminates and your engine may run poorly, stall, or refuse to start.
  • Advance Auto Parts carries camshaft position sensors for most vehicles and can cross-reference your VIN to find the correct part number.
  • Replacement typically costs between $150 and $400 in labor plus the sensor itself, though some vehicles are easier to access than others.
  • You can purchase the sensor at Advance Auto Parts and install it yourself if you have basic mechanical skills, or use it as the part for a professional mechanic to install.

Signs your camshaft position sensor is failing

The most obvious sign is a check engine light on your dashboard. When you see this light, you can take your vehicle to an auto parts store like Advance Auto Parts — many offer free code reading. A failing camshaft position sensor typically triggers codes P0010, P0014, P0016, P0017, P0018, or P0019, depending on which sensor failed and your vehicle's configuration.

Before the light comes on, you may notice the engine running rough at idle, hesitation when accelerating, or a noticeable drop in fuel economy. Some drivers report that the vehicle starts but then stalls when ready, or that it cranks but will not turn over at all. These symptoms can also point to other problems, so a code read is the fastest way to confirm the sensor is the culprit.

If you ignore a failing sensor, you risk stalling in traffic or being stranded. The engine will not damage itself from a bad sensor, but you will lose drivability and fuel efficiency until the part is replaced.

How to find the right sensor at Advance Auto Parts

Bring your vehicle's VIN to an Advance Auto Parts store or look up your vehicle on their website. The VIN is printed on your registration, insurance card, or the dashboard on the driver's side. Enter it into their parts finder tool, and the system will show you the correct camshaft position sensor for your engine.

If you are ordering online, you can also call the store directly and give them your VIN over the phone. Advance Auto Parts staff can confirm the part number, tell you whether it is in stock, and sometimes arrange for in-store pickup the same day. Prices vary by vehicle, but sensors typically range from $40 to $150 for the part itself.

Some vehicles have multiple camshaft position sensors. The parts finder will show you how many your vehicle has and where each one is located. If you are unsure which one is failing, the engine code from your check engine light will tell you — codes ending in "A" usually refer to the intake camshaft, and codes ending in "B" refer to the exhaust camshaft.

Installation: DIY versus professional mechanic

Camshaft position sensors are among the easier engine sensors to replace on many vehicles. On some cars, the sensor is mounted on top of the engine or on the side of the cylinder head, taking 15 to 30 minutes to swap out. On others, it sits deep in the engine bay or requires removing the valve cover, which can take an hour or more.

If you choose to install it yourself, you will need basic hand tools — usually a socket wrench and a screwdriver. Advance Auto Parts sells the sensor, and their staff can point you toward online tutorials specific to your vehicle's year, make, and model. You do not need to disconnect the battery on most vehicles, but check your owner's manual or a repair guide first.

If you take it to a mechanic, labor costs typically run $100 to $300 depending on how hard the sensor is to reach. A dealership may charge more; an independent shop may charge less. The total job — parts and labor — usually falls between $150 and $400. Getting a quote from your mechanic before you buy the part ensures you know the full cost.

What to do after you replace the sensor

After installation, the check engine light should turn off within a few driving cycles. If it stays on, the code may have been misread, or there may be a second problem. Some vehicles require you to clear the code manually using a code reader, which Advance Auto Parts can do for free at many locations.

If the light returns after a few days of driving, the new sensor may be defective or the original diagnosis was wrong. Return to Advance Auto Parts with your receipt — most sensors come with a warranty covering defects. If the problem persists, have a mechanic scan the code again to see if it is the same code or a different one.

Camshaft position sensors do not require maintenance and should last the life of your vehicle if they are not defective. Once replaced, you should not need another one unless it fails prematurely.

Advance Auto Parts warranty and return policy

Most sensors sold at Advance Auto Parts come with a manufacturer's warranty covering defects. The length varies — some are 30 days, others are longer — so check the packaging or ask at checkout. If the sensor fails within the warranty period and you have your receipt, Advance Auto Parts will exchange it for a replacement at no charge.

If you purchase the wrong sensor by mistake, you can return it within a set timeframe if it is unused and in original packaging. Store policies vary by location, so ask at the register what the return window is. Opened or installed parts are typically not returnable.

Keep your receipt and the old sensor in case you need to prove the replacement was done. Some shops ask to see the old part before they will honor a warranty claim on the new one.

Frequently Asked Questions

Can a bad camshaft position sensor damage my engine?

No. A failing sensor will not cause mechanical damage to your engine. It will prevent the engine from running correctly and may cause it to stall or refuse to start, but the engine itself will not be harmed. Replacing the sensor restores normal operation.

How much does a camshaft position sensor cost at Advance Auto Parts?

Sensor prices range from roughly $40 to $150 depending on your vehicle's make, model, and year. Labor to install it at a mechanic typically adds $100 to $300. Check Advance Auto Parts' website or call your local store with your VIN for an exact price.

Do I need to replace both camshaft position sensors if one fails?

No. Replace only the sensor that is failing. Your check engine code will tell you which one — codes ending in "A" point to the intake sensor, and "B" points to the exhaust sensor. Replacing both is unnecessary unless both are actually failing.

Will my car run without a camshaft position sensor?

Most modern vehicles will not start or will stall when ready without a working camshaft position sensor. Older vehicles with simpler engine management may limp along briefly, but performance will be severely degraded. The sensor must be replaced to restore normal operation.

Can I clear the check engine light myself without replacing the sensor?

You can clear the code temporarily using a code reader, but it will return within a few driving cycles if the sensor is still faulty. The underlying problem must be fixed. Advance Auto Parts offers free code reading to help you confirm the sensor is the issue before you buy a replacement.