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

Last Updated on January 24, 2022

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.

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.

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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, P0016 Code, P0340 Code, P0341 Code, P1345 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.

Tip

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.

 

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

  1. I have a Nissan teana j30, V6 engine.
    It would switch off when in motion leaving the dashboard on, fail to start there and then unless after some minutes. The dashboard has an engine check light.
    Had it scanned and showed camshaft position sensor B1 being faulty but the engine has two camshaft position sensors. 1. Will it be okay to replace both?
    2. Will the problem be solved completely?
    3. What causes faulty camshaft position sensors?
    4. What will be other possible problems I should anticipate after fixing this?

    Reply
    • 1. It is okay to replace both, worst case you lose money by replacing a working sensor.
      2. Hard to say. Often the problem is not the sensor itself, but a timing issue that triggers the camshaft or crankshaft sensor code. This could be an issue with the timing belt/chain, tensioner, or variable valve timing (VVT) system.
      3. Depends on the type of camshaft sensor. Some are mechanical and wear over time. Others are electrical and short out. This could also be a symptom of a bad ground somewhere else in the wiring.
      4. I’m not sure I understand the question; fixing the problem shouldn’t cause another. If you replace the sensors and the problem persists or a new one surfaces, the camshaft sensors were probably not the root cause of the problem.

      Reply
  2. I have a 2007 BMW 328i coupe. It came up with a P0012 code. The guy tells me it is a camshaft sensor problem. How much should I expect to pay for this repair? I had vehicle stalling happen only once. I do not hear any noises or rattling sounds.

    Reply
    • Shouldn’t be too expensive, but it’s best to get a few quotes from places in your area for an accurate estimate.

      If your camshaft position sensor is bad it’s best to replace it as soon as you can, especially if the vehicle stalled from this issue. Try to verify the sensor is actually bad before you replace it as, this code is sometimes indicative of other timing or wiring issues.

      Reply
  3. Hello I want to know my car was driving ok and I noticed once I got on main road felt like if car stayed stuck in like second or third gear got home park and got on road for like 5 min then like switched gear on it own then tried taking off and barely want to move rpms went up took time to catch speed can that be a sensor problem I have a 200 Infiniti g35

    Reply
    • Sounds like you may be in limp mode. Limp mode commonly limits which gears you can be in, especially when the problem is with the transmission. Is your check engine light on? What are the codes?

      Reply
  4. I’m battling issue of this nature in my 2010 Ford galaxy 2.0tdi (hdi). Engine will stop suddenly while driving without any warning. “Engine maulfunction” on dash.
    Insufficient fuel supply code P0003. And P2002, P0380, but they would not stop hot engine running at 2500 rpm.
    Car will only start again with easy start spray. Then will drive for 5-15minutes and will do the same again.
    Any ideas? Could camshaft location sensor to blame?

    Reply
    • I doubt it, this sounds like a fueling issue to me. You’ll have to do some troubleshooting to determine the problem. Maybe a dying fuel pump, a clog somewhere, or something else of that nature.

      Reply
  5. Sean, I’ve seen a lot of Audi comments on this thread, well here’s one more. Audi q5 2011. For a while the oil sensor was off, then the epc light went off and stalled the car out. Code reader said camshaft sensor is bad. Replaced it, I realize after reading your instructions I didn’t unplug the battery. It’s still doing the same thing, stalling out epc code etc.

    Reply
  6. Hallo ik heb een Jaguar x type 2.2 diesel uit 2009
    Auto vorig jaar gekocht met 193000km op de teller
    Rij al een jaar heerlijk mee zonder enige problemen
    Sinds 5 weken sloeg motor tijdens rijden af en toe af en kreeg ik transmissiestoring in het dashboard te zien
    Auto uit laten lezen en gaf de volgende storingen aan
    P1211
    P0251
    P1700
    Hij gaf ook aan:
    Motorkoppelsignaal: niet bijgewerkt
    Motorkoppelsignaal: kwaliteitsfactor is gelijk aan nul
    P1719: Intermitterend—motorkoppelsignaal
    Heb de auto naar diverse garages gebracht en niemand kon er wijs van worden.
    Soortgelijke pech onderweg gehad anwb erbij laten komen heeft m uitgelezen en volgens anwb kon het een van de injectoren zijn
    Man. An anwb heeft er nog een stukje mee gereden en reed best wel belabberd horten en stotend maar sloeg niet af
    Advies: breng m naar een garage en laat de injectoren nakijken.
    Nou dat heb ik gedaan
    De garage heeft alle vier de injectoren eruit gehaald zonder problemen
    Injectorspecialist heeft aangegeven Alle vier kapot!!🤨🧐🧐
    Garage vier andere gebruikte injectoren erin gedaan
    Auto gestart en motor draaide in eerste instantie goed (volgens garage)
    Monteur zegt wou er ff een stukje mee rijden en voor hij de straat uit was hoorde hij de motor heel erg beroerd lopen en er gelijk mee terug naar de garage en nu blijkt de hele motor kapot
    Reparatie van m’n eigen motor zou de kosten erg laten oplopen
    Advies van garage
    Een andere gebruikte motor zoeken.
    Als ik eerlijk moet zijn voel ik me een beetje belazerd maar ik kan dat niet met zekerheid zeggen of bewijzen dus ik weet ff niet wat ik moet doen.
    Helpppppp!!!! Aub

    Reply
  7. Hey Sean, Thanks for sharing your experiences with all the drivers her. Recently I was driving g my Kia sorento 2019 desert highway in dubai with 45C where all of the sudden vehicle started to jerk, I have try to accelerate but it wouldn’t go an faster and the speed was reducing, since I was in highway and were with family I tried to let it reach to the nearest village so I can have it checked. because of the hot weatger the temp indicator reached to middle where normally its 1 line before the mid. I took it to workshop they had it checked and found the catalytic c was broke “idk if it was due to the heat and pressure”. They had it removed and car ran OK the next day morning with colder weather it again started the same problem, now I have my own OBD reader and it appears p0390 camshaft position bankB I’ve unplugged the connector it showed camshaft failure. Now the symptoms includes a noise when at 5k RPM from the engine. I’ll appreciate your informative reply

    Thanks
    Sal

    Reply
    • Hey Sal, it’s pretty hot over there. Check to make sure there’s nothing obstructing the radiator. Debris blocking the radiator fins could cause some cooling issues.

      I don’t know about the camshaft sensor. I would test the sensor according to the procedure in the factory service manual (Kia should specify exactly how to test that the sensor is good). If the sensor comes back OK, check the fuses and wiring to make sure there are no issues there.

      Reply
  8. I have a 2011 Jeep Grand Cherokee and I my check engine light 1st code is P0369 camshaft position sensor DTC bank 1 sensor 2
    Had the camshaft sensors replaced
    Check engine light came back on with the same code P0369 but now says “sensor B circuit bank 1.
    My mechanic switched the sensors around and checked the wiring.
    Check engine light came back on same code as the 1st one
    HELP PLEASE

    Reply
  9. Hi. I recently got an oil change and a day later my oil light kept blinking, (I reset the miles). It was blinking for about 2 weeks and then it went off and the check engine light is on. The car jerks like it just wants to shut off. Codes P0014 and P0017 come up. I need to take to mechanic 2 miles away from my house, would driving it there be okay considering I don’t have money for a tow truck, also what could possibly be the issue

    Reply
    • Use your best judgment on that. Is it 2 miles of quiet neighborhood roads or 2 miles of freeway? I would not drive the car very fast or hard until you know what’s wrong.

      Reply
  10. Hi Sean
    I have a 2010 Ford Focus st that has been at the mechanic for 8 months(5 months with 1 and 3 months at the other). Engine ceased randomly while driving. First mechanic seems to have had no idea what was up and kept going round in circles, it was leakage in the samp etc etc etc . Second guy said the Engine needed to be stripped, did that, gave the car back, had it for 1 day and it wouldn’t start without jump starting, took it back and was told it was the fuel pump, replaced it then it was the radiator, car still would start and stall so then it was the camshaft gear then the sensor and now the latest is that he needs to replace the vanos which he says costs over R7000 so he’s trying to get a second hand one. I can’t seem to find any pricing on the net for this. Please help, at my wit’s end and unable to sell the car at this point as I’ve spent over R12 000 on it already and not in a position to buy. Is there any hope at all? I’m also worried that I might be getting played.

    Reply
    • Hey Amy, it sounds like this may be an older car with a lot of deferred maintenance. Without seeing the car I can only guess as to what the issues are, and the validity of the diagnoses. Consider asking around your area to find out which shops are the most trustworthy. At that point, you’re best off trusting the mechanics at that one shop to do good work. Try to get the car into a state where you can sell it or drive it.

      If you do end up selling the car and buying another, I strongly recommend you have the vehicle inspected by a mechanic. You could also take a car savvy person with you to help you through the buying process. Have your friend inspect the car inside and out (also checking underneath the vehicle) to see what the potential problems may be. Ask for all service records. Know what service that vehicle will need in the near future, and make sure you have the budget for any upcoming repairs.

      Reply
  11. Hi My Honda accord model 91 fly bolts loosed out leaving only two bo bolts holding the fly wheel un known to me .not until I started hearing a very rough sound within gearbox axis. So I quietly drove it back to garage. It starts each time I tried to show my mechanic how it behaves a little while it couldn’t start again but the mechanic managed to remove some sticked bolts in between the gear box and flywheel. It’s has automatic gear box. Since thar day it could not start for once. Plugs spark and engine crank fuel supplies. No start. What could be the problem.

    Reply
    • Sounds like something wasn’t put back together correctly after the transmission work. Have the mechanic double check his work. Since he was the last one in there, he should probably be the one fixing the no start condition.

      Automatics don’t usually have a flywheel. They have a flex plate and a torque converter instead.

      Reply
  12. Sean, thank you for offering clear and easy to understand replies to questions.
    I came here to find out about cam shaft sensors and I did find the answers in
    your replies to other people’s questions. Many thanks.
    Martha.

    Reply
  13. Good afternoon,
    I have two Saturn Astra’s (Opel Astra), GM 1.8 ecotec . Bought one new and the other recently (85kMiles). I have had to replace the Cam Position Sensors on my original car a few times (130k milks). The 85k car gave me the same surging symptoms, pulled a code and noted that the CPS was failing. I replaced them both. However the surging is still occurring and not check engine light. I also replaced the CPS again, then swapped them and experience the same issue. Is it possible for the point on the cam that it reads from may be ‘dirty’? I have checked for vacuum leaks using the starting fluid method, I have replaced the PCV valve in both cars when I replaced the valve cover gasket (while you’re in there…). I also got a lean code when the CPS failed originally. The 130k car runs perfect and have not had an issue in some time.

    Reply
    • I think rather than a dirty point on the cam, you may have a dirty or corroded connection in that section of the wiring harness. Most camshaft sensors are electromagnetic so a dirty cam probably won’t affect the reading.

      Reply
  14. Hi Chris,
    I have a Toyota Camry 2008 model and of recent I discovered that after going some distance the car start to jerk and the speed reduces. Shortly I couldn’t start the engine anymore, its just rolling. When I checked the engine it’s saying Camshaft position sensor, could it be the issue. Please help

    Reply

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