Camshaft Position Sensor

Car part Category: Sensors DIY difficulty: Easy–Moderate (DIY)

What it is

The camshaft position sensor tracks the rotation of the camshaft so the engine computer knows which cylinder is on its compression stroke. It works together with the crankshaft sensor.

What it does

Its signal lets the computer time fuel injection and spark precisely and is essential for sequential injection. A failing cam sensor causes hard or no starting, stalling and timing-correlation codes such as P0340/P0341 (or P0016).

Symptoms of failure

  • Codes P0340, P0341 or correlation code P0016
  • Hard starting or no-start
  • Stalling and intermittent cut-outs
  • Hesitation and rough running
  • Reduced power / limp mode

Common fault codes

Which vehicles need it

Most modern engines, including VVT engines where the sensor also feeds variable valve timing.

Replacement cost

DIY (part only)$20–$100
At a shop (parts + labor)$120–$350
Replacement intervalNo set interval — replace on failure.
DIY difficultyEasy–Moderate (DIY) — usually one bolt and one connector; access varies
Recommended brandsBosch, Denso, Standard Motor Products, Delphi

Where to buy the part

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Frequently asked questions

Can a car run with a bad camshaft sensor?

Sometimes it will run poorly on the crankshaft sensor as a backup, but expect hard starting, stalling and limp mode. A complete failure can cause a no-start. Replace it promptly.

What is the difference between the camshaft and crankshaft sensor?

The crankshaft sensor tracks the crank (engine speed and basic timing); the camshaft sensor tells the computer which stroke each cylinder is on. A P0016 means the two are out of correlation — often a timing or VVT issue, not just a sensor.

Confirm the fault first: OBD-II scanners →