Crankshaft Position Sensor

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

What it is

The crankshaft position sensor monitors the rotation and position of the crankshaft. It is one of the most critical inputs the engine has — without it, the engine usually will not run at all.

What it does

It tells the computer engine speed (RPM) and crank position so it can time spark and fuel. A failing crank sensor is a classic cause of intermittent stalling and sudden no-starts, and it sets code P0335.

Symptoms of failure

  • Code P0335 (crankshaft position sensor circuit)
  • Intermittent stalling, often when hot
  • No-start (no spark, no injection)
  • Hard starting and hesitation
  • Tachometer dropping to zero while driving

Common fault codes

Which vehicles need it

Every modern engine. Heat-related intermittent failure is a well-known pattern on many models.

Replacement cost

DIY (part only)$20–$100
At a shop (parts + labor)$150–$400
Replacement intervalNo set interval — replace on failure.
DIY difficultyModerate (DIY) — one bolt and connector, but the location is often awkward
Recommended brandsBosch, Denso, Standard Motor Products, Delphi

Where to buy the part

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Frequently asked questions

Why does my car stall only when it is hot?

A classic symptom of a failing crankshaft position sensor: heat expands a tiny internal crack, the signal drops out and the engine stalls, then it restarts once it cools. A P0335 with hot-stall behaviour points strongly to the crank sensor.

Will a bad crankshaft sensor cause a no-start?

Yes. Because the computer needs the crank signal to fire spark and fuel, a fully failed sensor usually means the engine cranks but will not start.

Confirm the fault first: OBD-II scanners →