P0335

What this code means

The crankshaft position sensor tells the engine computer exactly where the crankshaft is and how fast it's turning. The computer uses that signal to time the spark and the fuel injectors. P0335 means the computer either lost that signal, saw it cut in and out, or saw something in the signal pattern that didn't make sense. The code points at the sensor's circuit, not necessarily the sensor itself. Wiring, a connector, or the reluctor wheel the sensor reads off of can all cause the same code.

Is it safe to drive

Be careful with this one. A car with a failing crank sensor can stall without warning, sometimes at idle, sometimes at speed, sometimes only when the engine gets hot. If it stalls while you're driving, you lose power steering assist and brake booster vacuum at the same time, which makes the car much harder to control. If the check engine light is flashing, or the car has already stalled and restarted, don't keep driving it around. Get it looked at or towed in. If it's just the light on and the car is running fine so far, get it checked soon rather than waiting.

What commonly causes it

Wiring and connector problems are the most common cause, especially on engines where the sensor sits close to the exhaust manifold. Heat cycles dry out and crack the insulation over years, or corrode the connector pins. After that, the sensor itself failing is the next most likely thing. Less often, a stretched timing chain or a damaged reluctor ring on the crankshaft throws the signal off even though the sensor and wiring are fine, and on higher-mileage engines this is worth ruling out before replacing parts. A bad engine computer causing this is rare. Which of these is likely depends some on the engine. Some engines are known for eating crank sensors themselves. Others rarely fail that way and it's almost always wiring or connector corrosion.

Diagnosis and rough cost

Diagnosis means putting a scan tool on the car to see whether the crank signal is missing entirely, weak, or erratic while cranking or running, and comparing it against the camshaft sensor signal. That usually means checking wiring for resistance and continuity and inspecting the connector by hand, not just reading the code and swapping the sensor. If it turns out to be the sensor, replacing it usually runs somewhere in the low hundreds of dollars including labor, though this varies a lot by engine since some sensors are easy to reach and others are buried behind the harmonic balancer or timing cover. If it's wiring or a connector, cost depends on how much of the harness needs repair. We'd rather find out which one it actually is before quoting a number.

Generic OBD-II guidance — manufacturer-specific codes and causes vary by make, so always confirm against your vehicle. A code identifies a system or condition; it does not, on its own, prove which part has failed.