7 Symptoms of a Bad Camshaft Position Sensor (and Replacement Cost)

Last Updated on January 19, 2021

The camshaft position sensor (CMP) is just one of the many electrical parts found in a vehicle. We’ll go over what this component is, the symptoms of a bad camshaft position sensor, and what you can expect its replacement cost to be when it’s faulty.

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A lot of people confuse the camshaft position sensor with the crankshaft position sensor because they sound similar. But there’s a big difference between the two as they perform different functions in the vehicle and have different symptoms when something goes wrong with them.

What is a Camshaft Position Sensor?

what is a camshaft position sensor

Every modern-day vehicle has a camshaft position sensor. This sensor is a very important part of any vehicle because it helps ensure that the engine is running properly.

You may have trouble spotting the sensor when you look under the hood of your car. Usually, different car manufacturers will have their own unique spot near the engine for mounting the sensor. You may find it either in back of the cylinder head, in the lifter valley of the vehicle, or next to the engine block.

The purpose of a camshaft position sensor is to determine the position of the camshaft as it relates to the crankshaft. This data is then sent to the powertrain control module (PCM) for use with fuel injector and/or ignition system control.

Common Symptoms of a Faulty Camshaft Position Sensor

#1 – Check Engine Light Illuminates

check engine light on

When your camshaft position sensor is faulty or starts having issues, the first thing you should notice is that your “Check Engine” light comes on in your dashboard. Obviously, the “Check Engine” light could indicate a variety of problems and not necessarily a bad camshaft position sensor.

In this case, you should either use an OBD2 scan tool to retrieve the stored diagnostic trouble code(s) in your car or have a professional mechanic perform an inspection of the vehicle’s engine control module to see what is going on. They too will scan this module in order to receive a series of error codes which will indicate to them what the real problem is.

Please do not ignore or postpone scanning your vehicle or getting it inspected when your Check Engine light turns on or else your engine could end up getting seriously damaged. The engine could even end up failing altogether, which means you’d end up having to either rebuild or replace your engine.

Related: P0010 Code P0011 Code P0013 Code

#2 – Ignition Problems

bad ignition coil symptoms

As a camshaft position sensor starts having problems and weakens, the transmitted signal to the car’s computer weakens as well. This means the eventually the signal is so weak that it will not allow the car to start since there will be no spark from the ignition.

#3 – Car Jerking or Surging

car jerks when accelerating

If you are driving your vehicle and the camshaft position sensor starts failing, the engine will at times simply lose power and cause your car to jerk or randomly surge forward.

These are both a result of an improper amount of fuel being injected into the cylinders since the PCM is getting incorrect information from the camshaft position sensor.

#4 – Engine Stalling

rough idling

An even worse scenario than not being able to start your car is that your engine actually shuts off or stalls while you’re driving because the fuel injectors aren’t being told to inject fuel into the engine cylinders.

We probably don’t need to tell you how dangerous that situation could be.

#5 – Poor Acceleration

reasons and causes of car not accelerating

Aside from jerking, your vehicle won’t be able to accelerate very fast when your camshaft sensor begins to fail. Heck, you’d be lucky to accelerate past 30 miles-per-hour in some cases. The poor acceleration is again due to incorrect fuel delivery by the injectors.

#6 – Problems Shifting 

automatic transmission shifting

Certain models of cars with a bad camshaft position sensor will end up with a locked transmission that stays stuck in a single gear. The only way you’ll be able to get out of that gear is to shut off your engine, wait a bit, and then restart.

This is only a temporary solution and the problem will reappear so replacement of the sensor is necessary as a permanent fix.

Along with this, your vehicle may put itself into “limp mode” which won’t allow you to shift gears or accelerate beyond a certain speed.

#7 – Bad Fuel Mileage

poor gas mileage

This is the opposite of not delivering enough fuel to the engine. In this case, because of an inaccurate reading from a bad camshaft position sensor, more fuel than necessary is injected into the engine which causes your fuel economy to drop.

Camshaft Position Sensor Replacement Cost

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camshaft position sensor replacement cost

To replace a camshaft position sensor, you can expect to pay anywhere from $95 to $200. Parts alone will run about $25 to $100. Labor costs will be in the range of $70 to $100 for professional replacement.

Expect to pay more if you have a luxury vehicle or are having your local car dealership perform the replacement. There will also be additional fees and taxes added on to these costs as well.

Can You Replace a Camshaft Position Sensor Yourself?

Yes. This is one of those jobs that almost anyone can do and is an easy way to save yourself the minimum labor fee (often close to $100) that a repair shop or dealership will charge you. It should take about 5-10 minutes to replace it.

How to Replace a Camshaft Position Sensor

  1. Disconnect the negative battery cable.
  2. Locate the sensor. It’s usually on the top, front, or rear part of the engine. It will likely have a 2-3 wire connector attached.
  3. Release the tab on the sensor to disconnect the wires from the sensor.
  4. Remove the mounting bolt which attaches the sensor to the engine. It’s usually an 8mm or 10mm bolt.
  5. Pull the sensor off with a slight twist.
  6. Apply a bit of engine oil to the o-ring of the new senor.
  7. Install the new camshaft position sensor and secure with the mounting bolt.
  8. Reconnect the wire connector to the sensor.
  9. Reconnect the negative battery terminal.


When you bring your vehicle in to a dealership or repair shop for routing service or a tune-up, the mechanic won’t normally inspect the camshaft position sensor if they are not asked to.

If you have experienced any of the warning signs listed above, let them know you think it may be the camshaft position sensor. This will allow them to quickly inspect the camshaft position sensor to determine whether it’s causing these problems.


68 thoughts on “7 Symptoms of a Bad Camshaft Position Sensor (and Replacement Cost)”

  1. I have just replaced top gasket and had the check light come on thinking it was bad cam timing I advanced the cam two teeth. The car pulled better but still had the light on I have replaced the cam sensor as the old one was definitely faulty but now still have the light on would the cam timing been changed cause this ???

    • This would cause it yes. The cam is out of time with the crank shaft.

      You will need to turn the light off now though. If the timing is correct, the light will stay off.

      • This is helpful to me cos I’m having a challenge of a cam sensor even the obd is picking up that sensor but I wasn’t aware that it can cause the engine not to run well. …..

      • My position sensor keeps sending a code saying it’s bad I was told to replace the plugs so I did that. The code is still getting thrown that the sensor is bad when it’s cold and I turn my heat on. Any ideas what this cold be

        • This was educative!
          I have an issue with my car, it’s gear doesn’t select. The mechanic has checked the gear and certified it OK. He changed the speedometer & other sensors, yet it’s not selecting.
          What could be the missing link. It’s a Nissan Quest 2002/2005.

    • I believe with all the “pulls” you were pushing the engine too hard without the sensor being good. This sensor goes bad on me alot so I just domt drive it past 3000 rpms to be safe. These audi problems are ridiculous

  2. my Elantra 2002 when starting immediately shoots to 2500 rpm and stays there constantly. I put it in drive and then when I pull away it will not shift gear until it reaches 4000 rpm. Could this be the cam sensor? The Hyundai dealership just changed my throttle sensor thinking this was the solution but it was not.
    Thanks. Ant

    • Throttle position sensor would have been my guess too. Check the MAF (mass airflow sensor) as well to see if it’s dirty and listen for any vacuum leaks in the engine bay. Camshaft sensor is possible.
      The late shifts could be unrelated. Transmission fluid level is fine? Have you scanned it for any trouble codes?

    • Engine stalls while driving and make it impossible to start again. It would start immediately the next day may be, but stalls while driving.Engine check light is turned on. Scanner shows Cam shaft position sensor error, it was replaced. But still same problem. Car is Toyota corolla 2012

    • Yes, the check engine light has to be reset with a scan tool. Any mechanics shop can do this or you can buy your own tool and do it yourself. But if the problem is actually fixed, if you drive around long enough the light will sometimes reset itself if the onboard computer rechecks the area and this time discovers no fault. For some cars, disconnecting the battery for a few minutes may also reset the light.

      • Will the check engine light being on after repacing the camshaft position sensoron my 2004 Nissan MAXIMA cause it to still run the same as if the old cps was on because the computer still thinks the old cps is still sending that same error code?

        • No. If your new sensor is good, you may still have a code if that code hasn’t been cleared. However, the ECU should not have any memory of the old sensor.

          As the name implies, a camshaft position sensor merely relays the position of the camshaft(s) to the ECU. This is done so the ECU knows when to fire each spark plug.

  3. I replaced CPS, just as instructed. Engine stalls now (worse). Could connector need replacement also? Old sensor showed ‘melt’ on that end, was tight to remove.

  4. I’ve got a 04 Lexus RX330 and my FIXD app reported the P0346- cam sensor A circuit range/performance bank 2

    I noticed a problem when I had a hard time starting the car this morning. It cranked, but took a couple tries to get it running. Engine light and VSC light came on.
    After reading the article, other things are making sense like poor/rough shifting. I think I could replace the cam sensor myself as long as I can access the bank, but don’t know where that is. Only problem is, If the starter is failing, which may have been the reason for the tripped code, I don’t think it is worth the time, effort, and frustration trying to do it myself. I’ve got it in to the dealer now and waiting to hear what they say needs to be done.

  5. Could the battery be the cause of a bad cam sensor. I was told that my battery has a default and although it performs it is affecting the car’s performance….

    • It’s possible since (like any sensor connected to the car’s computer) it requires constant voltage from the batter. Before replacing the battery, check the battery terminals to make sure there’s no corrosion and that they’re tightly connected to the battery posts.

    • It can be a variety of issues but commonly a fuel pump or fuel filter issue. Have the car scanned to see if any fault codes pop up to help with diagnosis.

    • My Holden Rodeo has issues when I start the engine it revs fine but when I shift to drive it moves the ute, but the rev gets stuck at 1400 rpm for few seconds before it jumps. This only happens when the engine is cold. Before this issue started I notices the diesel consumption was more then normal.

  6. I have replaced my camshaft on my GMC terrain but the light came back on with 3 more camshaft errors and I can tell something is not right.

  7. I’m getting a engine light code P0013 (camshaft position actuator solenoid valve control circuit) on my 2011 Chevy Malibu. Running rough and slight loss of power. I have a notice of a “if this happens we’ll fix it” from GM for the throttle position sensor. Could this be the fix I need?

  8. I have a 2017 Buick Verano and my car stopped on me 4 times last night. As soon as I turned it on, when I tried to back up twice, and when I finally pulled forward. My check engine light came on as well. I finally got my car started and was able to get to an Auto Zone nearby. The code came up as P0010 and stated that I needed to replace my CMP actuator solenoid. Not even an hour later, the check engine turned back off. I am not sure if I should trust Auto Zone’s machine per the mechanic. The dealership can’t fit me in and neither can another place that I trust.

  9. 2015 GMC Terrain, replaced the CMP on the exhaust side after getting the code from the check engine light. A few months later the car is beginning to stall at low speeds (or immediately after shifting from park to drive) and I now have another check engine light. I plan to take this in for service in the morning. Could it be possible the new CMP was a bad part? Or could the CMP on the intake side now be bad? Not really sure of the difference in the two.. Thanks.

  10. I have a 2010 lotus evora , the car wont start , i was getting the PO-341 error code , so i replaced the camshaft sensor , still nothing .
    Any ideas out there that is causing this error code.

    • How’s your battery? I’ve seen a few cases where a bad alternator was causing the camshaft position sensor code to be thrown.

  11. I need to replace the camshaft Bank 1 sensor on my 2015 F-150 Vehicle. Can you send a picture to show me where to locate the Bank 1 and Bank 2 sensors for my 5.0 Engine Vehicle?

  12. My 2007 Camry surges and jerks at different intervals nd goes off afterwards, it starts well and cranks normal when this happens check engine comes on and goes off itself when normal again, could this be the cam sensor? Pls help. Fuel pump has been changed still the same.

    • I’ve got an 09 Toyota Corolla s last week it died at the convenience store by my house and would not start it cranks and while cranking it will act like it’s going to start it eventually got towed after paying a huge tow bill and going through two jump start
      packs we got it home “buhbh,buhbuh,buhbuh,buhbuh,and can sometimes get it to start but it takes forever if I can get it to start and warmed up when I shut it off it will usually start right back up no problem but if it dies after restarting then it goes right back to not starting I put a code reader on it and the only thing I got from that was a bunch of misfire codes and a o2 sensor code that’s been there forever I’ve replaced the plugs the coil packs and still the same problem I am stumped and absolutely frustrated with the entire situation and I’m normally pretty good at working on cars can someone please help me b4 I go absolutely mad over this please

  13. My 2009 e 46 struggle to keep running after being ignited in the morning. I have to Rev it for sometime until warm. Then after driving about 50 kilometers it changes the acceleration and the then stalls and switches off. It won’t start after that for some minutes.

  14. I have a GMC 2006 envoy with a 4.2L L6. I keep getting a cps error code P0365, and P0366, P0365 referss to my CPS but I have just replaced my camshaft sensor and the code keeps coming back after resetting the codes. Code P0366 refers to the Camshaft actuator solenoid and I don’t know how that relates to the CPS. can you help me?

  15. I have a Toyota Tacoma it crank but won’t start. If I use the car today and park, the following morning it won’t start. I have had other things checked fuel pump nozzles, plugs, etc.
    I am going to change cam shaft and crank position sensors changed. Hopefully it will start.

  16. I have a 08 Chevy Cobalt it won’t start so I put a new starter on it bc it was bad I hooked it up to computer it said crankshaft and camshaft sensors I replaced those and it
    sstill won’t crank what else could it be that’s all my computer saids?

    • Generally a vehicle will crank (but not start) if the starter is good and has enough cranking amps from the battery, even if the camshaft or crankshaft position sensors are bad. I would have your car looked at by a local professional for further diagnosis.

  17. Hi I got certo forta 2009 the ECU biow I got it replace but it would start i check the injectors it have supply when first crank but would start the supply loss when l hold on the ignition key thank

    • Have you checked your fuel pump? If you’re not seeing supply while you attempt to start the car the fuel pump may not be delivering enough fuel to maintain pressure. You can perform a fuel pressure test to have a better idea if this is the cause.

  18. You are very knowledgeable about car breakdowns. I follow you from all social networks. I hope you will be more successful. thanks for everything

  19. I have a 2017 Elantra that has been dying when I slow to a stop, code showed bad camshaft sensors, replaced both lights went off but it is still doing it. Any suggestions.

    • Does it still die if you give it a little gas? You may have a vacuum leak or an idle air control valve issue that is causing it to idle poorly (or not at all), but drive fine otherwise.

  20. So I have a 2008 dodge carvian we change cam sensor and it work for like 5 min now it still jerks a lot when pushing gas what else could it be we got it check and they said it was cam sensor

    • It could be a lot of things. Check the wiring around the cam sensor to make sure the insulation is still good and none of the wires are hanging on by a thread.

      I had this happen to me one time. I went to start the car and it would just crank without starting. When I pulled off the cam sensor connector for an unrelated repair, one of the wires snapped. I had a check engine light for the cam sensor. The sensor was fine, I simply needed to fix the wire.

      How are your spark plugs? Old spark plugs can cause jerking and hesitation on acceleration.

  21. Hi I have an 03 chevy silverado with a 4.8l engine. The check engine light came on a couple weeks ago and had code 342 for camshaft sensor. We changed it last week and erased the code, was fine for about an hour and now we have a code 343 for camshaft sensor but with high voltage. I’ve been researching the problem and from what i can tell we needed to check our connections and make sure everything clean. My husband did all that this morning put back together and the code is gone BUT now it cranks but won’t turn on at all!! We are at our wits end!
    Could there be a timing issue?? I noticed that after he cranked it a couple of times that it would start prior to this morning. Made me think maybe timing off or??

    Any suggestions/ help/ ideas/ experiences would be greatly appreciated. With everything going on in the world right now we are just trying to make it to work. Really can’t afford to take to mechanic thanks in advance!!

    • If the engine can’t detect the camshaft position, it won’t be able to start. It sounds like you have a short or open circuit somewhere. Start by inspecting the camshaft sensor’s connector and see if any of the wires are broken.

      While I was working on my car for an unrelated repair, I went to start it and got a camshaft position sensor code. The root cause was a broken wire at the connector. I had unplugged the sensor as part of the repair, and the process of unplugging the sensor was just enough to finish off that poor old wire.

      Take a wiring diagram and figure out which way those camshaft position sensor wires run. You can try jiggling that section of the wiring harness to see if you can get the truck to start when the harness in a certain position. Be careful that you don’t do this so forcefully that you end up causing yourself another electrical headache, though!

      Another possibility is a bad ground. Again with a wiring diagram, locate the ground strap used by the camshaft position sensor. Make sure the ground is clean and tight.

  22. I have a 04 ram 2500 5.9 cummins my truck throws p0342 cam sencor light the dealer has done everything to fix it even as far as replacing the ecm 2x and taking out the cam

  23. My car is having a problem of engine light coming on when driving at 80 and goes away when restarting again and it comes on again when it reaches at 80

  24. I have a RAM 1500 5.7 Hemi, my engine light came on, took it to Napa to found out the code came back PO 335, which they said is a crankshaft position sensor, Napa gave me a new one, I unhooked neg battery terminal, took out old replaced with new, had them reset my computer. 15 mins later came back on and truck stalled a few times. Co what might be causing this failure, and engine light back on and also the traction light on dash stays on?? Weird.

    • Try having the computer scanned again to see if any other codes come up. There might be something wrong with the ECU or it may need an update, since those can cause various problems with the engine and throw codes that might not be true.

  25. Thanks for a work. My Corolla 2007 starts when cold but when I run the engine for about twenty minutes and off it, restarting becomes very difficult. What could be the problem?

  26. On the instruction on how to replace the camshaft position sensor the first thing it tell you is to disconnect the negative cable from the battery but at a local auto parts claims that on newer vehicles (which is funny as they don’t mention what a newer vehicle is, anything after 2000, 2010, 2021?) require to have a memory saver for the ECU if are disconnecting the battery or else. It sounded to me like they were trying to sell the battery saver. Then trying to research there are 2 camps one say that it is important to have it the other says it is dumb to have it as it will complete the circuit and bypasses the removing the battery cable safety all together.

    Is there any truth to this?
    Can anyone clarify (not guess as I keep reading guesses or “logical’ arguments)?
    Is there technical manual (or mechanics database) on any vehicle that says that is definitely is needed?
    If so, I there a way to tell which vehicles are like that?

    • Most ECUs have a form of permanent storage they can use for critical settings, so a memory saver shouldn’t be necessary. This is why you don’t lose the engine calibration when you disconnect the battery. Without a basic engine calibration, you wouldn’t even be able to start the car.

      You’re probably seeing a lot of guesses and logical arguments because nobody can reasonably make a blanket case statement saying “all ECUs are designed this way and it’s definitely safe for you”. One counterexample would defeat their argument.

      There are a lot of ECUs out there. ECUs are implemented differently depending on the year and manufacturer. Newer electronics are more sophisticated.

      The factory service manual is a book full of technical data from the manufacturer. It should do a good job of telling you what information is lost when you disconnect the battery on your specific car if there’s anything that would be noticeable to the driver, such as radio settings. The service manual may have a section on ECU data as well.

      Most factory manuals cost a bit of money and can be found online at your vehicle manufacturer’s website. If you want to see the manual for many vehicles, a subscription to a service such as ALLDATA or Mitchell 1 may be warranted.

  27. My daughter took her 2012 Ford Fiesta for inspection. Did not pass check engine light on & code P0017. She had the crankshft sensor replaced by a mechanic. After leaving the mechanic, check engine light came on. She turned around and went back to tell him. She was told to drive the car more. Why is this?

    • Sometimes it can take some time for the ECU to relearn after resetting codes. If the light is still on after a week or so of regular driving, take it back to the mechanic.

  28. Good day
    I have a 2014 model Ford Fiesta 1.4. I replaced my engine with an import engine and and replace the import engine’s sensors with my sensors from the engine that is not running.
    Everything is fine it’s just the camshaft sensor kick out a fault. I replaced it and all three sensor can’t be wrong. Could it be the timing that’s out?
    And I had to change my flywheel because the import one was too big, but the crank sensor don’t have problems.

    • What was the camshaft code? Perhaps there’s a small electrical issue like a short or bad ground after the swap.

      It’s possible the imported engine uses a different sensor that is not fully compatible with your factory harness or ECU. I would do a bit more research as a sanity check to make sure it isn’t something like that either.

  29. I had my camshaft sensor replaced recently, but it still has an epc light flashing on when im hitting the gas and the engine still shakes around. Could this be a wiring problem? what could be the problem if its still not working but my P0341 code still pops up and is still having bad camshaft sensor problems.

    • It could be wiring, a bad ground, or a poor connection in the camshaft sensor connector on the wiring harness side.

      You can do a visual inspection of wiring leading up to the camshaft sensor. Next try the wiggle test to see if the condition improves or worsens when you physically move the wiring harness around. If those tests are inconclusive, you may have to bust out a multimeter to do a bit of electrical diagnostic work.

  30. I have a Discovery Sport 2.2L diesel, the 2015 model. My vehicle shakes some times in the highway but after a while it goes away. Wondering it’s a bad camshaft sensor.

    • Did the vehicle throw a code that led you to believe it was a bad camshaft sensor? If so, what was the code?

      Shaking on the highway could be a lot of things. It’d be best to take the vehicle to a shop to have it inspected.

  31. I replaced the can shaft sensor because the code P0340 (1) came up. The light came back on and stays on. The vehicle runs fine. Should I check the 02 sensor, the Catalytic Converter, or get the computer checked. 2002 Mercury Mountaineer.

    • Check the wiring around the cam sensor if you can. It’s possible there is a short, maybe a broken wire or some worn insulation that exposes the bare metal of the wire.


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