Camshaft Position Sensor

For accurate fuel injection and perfect ignition timing, your vehicle's engine control unit (ECU) works with a lot of sensors located throughout the engine. One such sensor is the camshaft position sensor. This component gives the ECU information on the camshaft's rotational position. The camshaft's position determines what stroke the piston is on; the ECU uses the information to adjust fuel ignition so that fuel is fed to the right cylinder. The camshaft position sensor also updates the ECU of the cylinder currently firing, so that ignition timing can be adjusted for the other cylinders. Without the camshaft position sensor, there's no way for the ECU to achieve correct ignition timing and fuel injection. Considering the part's crucial task in engine operations, it's important that this sensor is kept in top shape. And don't fret if replacement is the best option. You can browse our catalog at CarParts.com to check out the topnotch camshaft position sensors we have in store for you.


• Plays a crucial role in ignition and fuel injection

• Signals the ECU about the camshaft's rotational position

• Helps you enjoy faster engine start-ups

Many people tend to bulk all problems under the hood under that vaguest of catch-alls: "engine trouble". The truth is that there are many other parts involved in getting your ride going that are more likely to be at fault-a camshaft position sensor is just one of them.

Simply put, a camshaft position sensor determines the position and rotational speed (in RPM) of the crank. This is important because this information is used to control ignition timing and/or fuel injection timing. All of that allows your engine to function in the oh-so precise way, with the absolutely perfect timing, that it requires. Without it, you're not exactly dead in the water immediately, but you'll be limping quite a ways-making for a very uncomfortable drive.

The absolute worst-case scenario with a faulty camshaft position sensor is that there is no spark in the cylinder-you'll be going nowhere real quick. The other things to look out for are:

1. Excessively long cranking when starting cold: your car makes a crink-crink-crink sound without ever starting up.
2. Frequent rough runs: you'll be driving along all right one moment and then things get inexplicably rough and your engine sounds like it is struggling.
3. Poor idling characteristics: you'll notice that when you're stopped (and the engine is still running) that the engine sounds like it's gasping for air.
4. Acceleration Stalls: you try to speed up and your engine suddenly dies.

Here are a few things that you have to look out for to make sure you get the perfect sensor for your ride.

• Know thy ride: Camshaft position sensors differ greatly in size, appearance, and fit between automobile makes and models so make absolutely sure that you check for an exact fit for your vehicle

*NOTE* There is no such thing as a Universal camshaft position sensor-look for tags that state that it is Direct Fit or OEM Specified

• Check for durability ratings: Specifically, you'll want a sensor that can withstand at least 300 degrees Fahrenheit, and is resistant to high humidity. Any sensors with a rating below that will likely break down far too easily.
• Be Protected from EMI: Sensors that are affected by electromagnetic interference (EMI) won't be as accurate, if at all effective. Makes sure the one you are getting is tried and tested for resistance to EMI.

So your engine won't start, it hesitates while idling or accelerating, it misfires too often, and you've finally figured beyond doubt that it's you ride's camshaft position at fault and nothing else-what's next? Unless you want to be driving on limp-about mode for some time, replacing that faulty sensor is in order. It should be mentioned that you could hypothetically repair a broken or damaged camshaft position sensor but it isn't advisable because you will not be able to vouch for the credibility of your repair job-you might end up spending more if you mess it up.

The following steps will walk you through the process of general replacement-it's a bit of a challenge, but it will certainly help cut down on costs. Just read through the steps carefully and you should be up and running in no time at all.

Difficulty: 6/10

• Your vehicle's original manual
• Replacement camshaft position sensor
• Flashlight
• Adjustable wrenches
• Flat/Philips screwdrivers
• Pencil or chalk

1. Always wear safety glasses/goggles and other protective equipment like gloves. Avoid open-toed footwear like flip flops or sandals.
2. Keep a notebook or paper and writing implement handy-this will help you keep track of any wiring lay outs to avoid confusion later on.
3. Before you chuck away your old sensor and put in the new one, compare the two to make absolutely sure you have the right one. Some stores do not allow you to make returns after you have attempted an installation.

1. Make sure your car is parked on a flat, level surface with the parking brake engaged and the wheels bolstered by something solid.
2. Lift up the hood of your vehicle and make sure it is secured with the hood prop.
3. Locate the camshaft position sensor. The appearance of the sensor varies depending on the specific make of your vehicle so refer to your manual to avoid confusion. Generally, however, you can find the sensor mounted at the front of the engine block with a wiring harness attached.
4. Once located, mark the position and placement of any readily visible portion of the sensor. This will make it easier to put in the new sensor.
5. Sketch the layout of the wiring harness-to make it easier to reattach later on-then carefully detach it. Again, the method of release varies with the specific of your vehicle: most are attached with release tabs that you simply have to push in while others can simply be pulled off. The trick is to carefully look over the surrounding area and the part itself with a flashlight.
6. Remove the camshaft position sensor itself. Once more, look around it to see how it is attached-expect to find at least one nut or bolt that you need to loosen to get the part out. A good thing to try here is to jiggle the sensor gently after you unscrew a bolt or nut. If it comes off easily, you're in the clear. If it doesn't, then find where it is still attached and unscrew or pull as appropriate.
7. Install the new camshaft position sensor-making sure to align it with the traced-out pattern from step 3. Reattach as appropriate (with nuts or bolts) and gently pull to test if it is securely attached.
8. Replace the wiring harness using your sketch from step 2 and your vehicle's manual as a guide. Double check the connections to make sure that you have got it right.
9. Test out your installation by starting your ride-if it roars to life, you're good to go!

• The camshaft position sensor is a small device that often uses a magnet to generate or vary an alternating current (AC) electric signal.
• It determines the position of the camshaft in relation to the crankshaft.
• CarParts.com offers a wide selection of cam sensors replacements, with prices ranging from as low as $3 to $260.
• A faulty camshaft position sensor is easy to trace and symptoms are pretty straightforward, such as illuminated Check Engine light, ignition failure, poor acceleration, and jerking.
• Typically, the camshaft position sensor fails after completing its service life, which is usually almost as long as your car’s expected life span.
• Faulty camshaft position sensor makes your car unsafe to drive due to sudden changes in its driving conditions.

Internal combustion engines are the most common type of engine powering the cars you see on the road. Powered by either gasoline or diesel, combustion engines consist of multiple mechanical parts essential for fuel combustion. The combustion process needs the right amount of fuel and vapor entering the valve at the perfect time. To time the opening and closing of the poppet valves, camshafts are installed on top of them.

Camshafts are shafts with rotating or sliding egg-shaped pieces of metal known as cams. The elongated side of the cam is what pushes the valve causing it to open, while the more rounded part closes the valve by bringing it back to its natural position. The camshaft is controlled by the timing belt, along with the crankshaft. The rotation of the camshaft is monitored by a device known as the camshaft position sensor, but what does a camshaft position sensor do?

The camshaft position sensor is a small device that often uses a magnet to generate or vary an alternating current (AC) electric signal. It determines the position of the camshaft in relation to the crankshaft. The signal is sent to the engine control module (ECM), which is then used to fine-tune the fuel injectors, as well as the spark timing.

Camshaft position sensors are usually installed right above the camshaft. However, there are varying camshaft position sensor locations depending on the make and model of your vehicle. Some cars have it behind the cylinder head, while some have it sitting near the engine block.

If you’re wondering how important a camshaft position sensor is, think of it as one of the components that ensures a well-running engine. Pay close attention to its condition, as damaged camshaft position sensors can result in poor engine performance.

How much is an OE replacement camshaft position sensor?

Camshaft position sensors are small devices that feature varying shapes and designs. CarParts.com offer a wide selection of cam sensors replacements, which price ranges from as low as $3 to $260. OE replacement camshaft position sensors are sold individually or as part of a kit. To save valuable time and effort, you may narrow down your search by indicating the year, make, and model of your vehicle on the filter tab.

A faulty camshaft position sensor is easy to trace and symptoms are pretty straightforward. However, since the symptoms are vague, they can be caused by other failing components as well. What we recommend is to let a certified mechanic examine your vehicle first before taking any action. Here are some of the faulty camshaft position sensor symptoms you need to be aware of.

Illuminated Check Engine Light

The Check Engine Light is a warning light for any issues related to your engine, including a bad camshaft position sensor. In short, the Check Engine warning can mean different problems and not just a failing camshaft sensor. You can pinpoint the issue using an Onboard Diagnostic 2 (OBD2) scanner. Modern cars now incorporate a built-in OBD2 system in them, though you can have an OBD2 scanner, which is a plug-in device.

Using the OBD2 scanner, you can determine what’s triggering the Check Engine warning light. It can also self-correct some issues like ignition failures and fuel mixture. Aside from using an OBD2 scanner, you should also let an experienced technician examine your vehicle.

Ignition failure

A damaged camshaft position sensor may fail to transmit signals to your car’s computer. If the signal transmitted to the ECM is weak, a spark in the chamber won’t ignite. Without a spark, it will be difficult for you to start your car.
Jerking or surging behavior

Another product of a bad camshaft position sensor is loss of power in the engine due to poor fuel mixture being injected into the cylinders. Poor mixture is caused by inaccurate data being sent to the computer. If your engine gasps for power, it causes your vehicle to jerk or may begin to occasionally surge forward.

Engine suddenly becomes underpowered due to poor acceleration

Poor acceleration can be due to a busted camshaft position sensor that’s transmitting incorrect signals to your car’s computer. This leads to poor fuel delivery by the injectors, which shorts your engine’s power.

Typically, the camshaft position sensor fails after completing its service life, which is usually almost as long as your car’s expected life span. However, some cases require you to replace the camshaft sensor sooner than that. Factors like heat from the engine can cause the sensor to deteriorate faster. Front end collisions that are hard enough to damage the components near and behind the engine can also cause the sensor to fail.

Prolonging an engine that’s not running in full capacity is the last thing you want to happen with your car. It could cause your engine to develop more problems, which could reach all surrounding components. If this happens, you could end up with more expensive services.

Another concern is that a faulty camshaft position sensor makes your car unsafe to drive due to sudden changes in its driving conditions. Stalling, jerking, and impulsive surges are just three of many issues to be concerned about. Make sure to contact your trusted mechanic as soon as you notice one or two of the symptoms listed above.

Choosing the right camshaft position sensor

Here are a few things that you have to look out for to make sure you get the perfect sensor for your ride.

Check for vehicle fitment

Camshaft position sensors differ greatly in size, appearance, and fit between automobile makes and models so make absolutely sure that you check for an exact fit for your vehicle

*NOTE* There is no such thing as a Universal camshaft position sensor—look for tags that state that it is Direct Fit or OEM Specified.

Check for durability ratings

You'll want a sensor that can withstand at least 300 degrees Fahrenheit and is resistant to high humidity. Any sensors with a rating below that will likely break down far too easily.

Be Protected from EMI

Sensors that are affected by electromagnetic interference (EMI) won't be as accurate, if at all effective. Makes sure the one you are getting is tried and tested for resistance to EMI.

So, your engine won't start, it hesitates while idling or accelerating, it misfires too often, and you've finally figured beyond doubt that it's you ride's camshaft position at fault and nothing else--what's next? 

Unless you want to be driving on limp-about mode for some time, replacing that faulty sensor is in order. It should be mentioned that you could hypothetically repair a broken or damaged camshaft position sensor but it isn't advisable because you will not be able to vouch for the credibility of your repair job-you might end up spending more if you mess it up.

The following steps will walk you through the process of general replacement-it's a bit of a challenge, but it will certainly help cut down on costs. Just read through the steps carefully and you should be up and running in no time at all.

Difficulty: 6/10

Tools & things you will need:

• Your vehicle's original manual
• Replacement camshaft position sensor
• Flashlight
• Adjustable wrenches
• Flat/Philips screwdrivers
• Pencil or chalk

General tips:

Always wear safety glasses/goggles and other protective equipment like gloves. Avoid open-toed footwear like flip flops or sandals.
Keep a notebook or paper and writing implement handy-this will help you keep track of any wiring layouts to avoid confusion later on.
Before you chuck away your old sensor and put in the new one, compare the two to make absolutely sure you have the right one. Some stores do not allow you to make returns after you have attempted an installation.

Step-by-step:

1. Make sure your car is parked on a flat, level surface with the parking brake engaged and the wheels bolstered by something solid.
2. Lift up the hood of your vehicle and make sure it is secured with the hood prop.
3. Locate the camshaft position sensor. The appearance of the sensor varies depending on the specific make of your vehicle so refer to your manual to avoid confusion. Generally, however, you can find the sensor mounted at the front of the engine block with a wiring harness attached.
4. Once located, mark the position and placement of any readily visible portion of the sensor. This will make it easier to put in the new sensor.
5. Sketch the layout of the wiring harness to make it easier to reattach later on-then carefully detach it. Again, the method of release varies with the specifications of your vehicle: most are attached with release tabs that you simply have to push in while others can simply be pulled off. The trick is to carefully look over the surrounding area and the part itself with a flashlight.
6. Remove the camshaft position sensor itself. Once more, look around it to see how it is attached-expect to find at least one nut or bolt that you need to loosen to get the part out. A good thing to try here is to jiggle the sensor gently after you unscrew a bolt or nut. If it comes off easily, you're in the clear. If it doesn't, then find where it is still attached and unscrew or pull as appropriate.
7. Install the new camshaft position sensor-making sure to align it with the traced-out pattern from step 3. Reattach as appropriate (with nuts or bolts) and gently pull to test if it is securely attached.
8. Replace the wiring harness using your sketch from step 2 and your vehicle's manual as a guide. Double-check the connections to make sure that you have got it right.
9. Test out your installation by starting your ride-if it roars to life, you're good to go