The camshaft position sensor does pretty much what its name implies: it senses the exact position of the rotating camshaft and provides that data to the PCM. From there, that information is used, along with data from the crankshaft position sensor, to manage ignition and injector timing. In addition to that, on modern vehicles with variable valve timing, there is a mechanism on one or more camshafts that advances the timing; the camshaft position sensor on those vehicles also monitors the VVT system’s operation. There is usually one sensor for each camshaft.
The sensor itself is a non-wearing part that is built simply; its main functional part is a coil of fine wire in a plastic housing that creates a magnetic field. This will sit very close to the tone ring attached to the camshaft. The tone ring spins with the camshaft and has notches or teeth formed in it that allow a varying signal as the spinning disc disturbs the sensor’s magnetic field. The result is a signal that the PCM uses to see the position of the camshaft.
Usually, the camshaft position sensor is on the top of the engine, inserted into the valve cover or the cylinder head, and is fairly easy to access and replace.
There are many possible codes pointing to a cam position error, but P0340, P0335, P0011, and P0016 are common ones. In some cases, a cam position fault can cause a vehicle to go into limp mode, but milder symptoms include weak acceleration, poor running, and reduced mileage.
Cost of Camshaft Position Sensor Replacement
On average, for most vehicles, it costs about $140 to replace a camshaft position sensor.
For some specific examples on common vehicles, using $150 an hour as a labor rate:
For a 2010 Nissan Altima with a 2.5-liter engine, the labor to replace the cam position sensor is .4 of an hour. A factory sensor lists for $105, or an NTK part costs about $65. This makes the job about $165 using OE parts, or about $125 using aftermarket parts.
For a 2008 Toyota Camry with a 2.4-liter engine, the labor time to replace the cam sensor is .5 of an hour. A factory sensor lists for $79, or a Beck/Arnley part costs about $60. This makes the job about $154 using OE parts, or about $135 using aftermarket parts.
For a 2014 Jeep Grand Cherokee with a 3.6 liter engine, the labor time to replace a cam sensor is .6 of an hour. A factory sensor lists for $65, or a Delphi part costs about $40. This makes the job about $155 using factory parts or about $130 using aftermarket parts.
In most cases, there would be a standard hour of diagnostic charges added to the above estimates. But it’s also common enough to just replace the sensor based on a trouble code.
What Else can Cause a Camshaft Position Sensor Code
If a vehicle shows up with an engine light for camshaft position problems, there are many possible causes. In most cases, it isn’t a sensor problem, but the actual testing of the sensor requires an oscilloscope, a pretty high-end scanner, or factory tools to take a look at the waveform of the sensor signal to get an idea of how well it is working. In most cases, this isn’t done, and the sensor just gets replaced.
Which can lead to a situation where the sensor has been replaced but the code comes back because the sensor wasn’t actually the problem. Often, the code indicates a problem with the VVT system’s operation. In that case, the first thing would be to verify the oil level and quality, as the VVT system relies on metered oil to operate. If that’s not it, then the oil control valves that meter the oil are checked, as they have screens that can be obstructed. Problems with those can cause a camshaft sensor code, as can problems with the camshaft phasers that they operate.
In many cases, a cam/crank correlation error is the source of the code. That means that the readings of the crank sensor and the cam sensor aren’t in agreement, which can mean that the timing chain or belt has worn or stretched. Timing chain work can be much more expensive and time-consuming to diagnose and repair than simply replacing the cam sensor. If the engine uses a timing belt, however, that should be inspected, ruled out, or replaced if it is due.
- Will the engine run if the camshaft sensor is bad?
Usually yes. The primary signal most systems need to run the engine is from the crank sensor. The cam position sensor is secondary, and most engines can run without it, though some will go into “limp mode,” which limits power and reduces performance.
- Can I replace my own camshaft position sensor?
Usually yes; most of the time the sensor is easily accessed and only held down by one bolt. On most engines, there is either no calibration needed or it is done automatically.
- Should I use OE parts?
Most mechanics would say yes; it’s a good idea to avoid problems or doubts, given that replacing the sensor can be part of the diagnosis. But it’s also easy enough to replace, and there’s always a warranty on that kind of part. If a new sensor works right out of the box, OE or aftermarket, it will likely continue to work fine indefinitely.