GarageGuideCrankshaft position sensor circuit
P0335 Code: Crankshaft Position Sensor A Circuit
P0335 stands for "Crankshaft Position Sensor A Circuit Malfunction." The crankshaft position sensor tells the computer how fast the engine is turning and exactly where each piston is. The computer uses that signal to time both the spark and the fuel injection.
This is one of the most important sensors on the engine. On many cars, if the computer loses the crankshaft signal, the engine simply will not start or will shut off while driving. P0335 means the computer is not getting a usable signal, which can come from the sensor, its wiring, or the toothed wheel it reads.
P0335 can leave you stranded or cause a stall while driving, which is a real safety risk in traffic. It should be diagnosed promptly.
If the engine has stalled or is hard to start, do not rely on it, especially in traffic or on the highway. Have it towed or driven only a short distance on quiet roads. If it runs normally and the code is intermittent, get it checked soon.
Symptoms you might notice
- Engine cranks but will not start
- Engine stalls suddenly, sometimes only when hot
- Tachometer needle does not move while cranking
- Intermittent stalling that restarts after cooling down
- Rough running or misfiring
- Check engine light on
Common causes
Failed crankshaft position sensor
Sensors often fail with heat. A classic pattern is stalling once the engine is fully warm, then restarting after it cools off.
Damaged wiring or connector
The sensor is mounted low on the engine where its wiring can be damaged by heat, road debris, or oil.
Debris on the sensor tip
Many crank sensors are magnetic and can collect metal particles that weaken the signal.
Damaged reluctor ring
The toothed ring the sensor reads can crack, shift, or lose teeth, giving a bad signal even with a good sensor.
Incorrect sensor gap after a repair
If the sensor was recently removed, an incorrect air gap or a damaged sensor can cause a weak signal.
Engine computer fault (rare)
Rarely, the input circuit inside the computer fails.
Before you buy parts
P0335 is a circuit code, so test before you buy. If your engine stalls when hot and restarts when cool, the sensor is a strong suspect. But check the connector and wiring too, and use a quality replacement sensor, because cheap crank sensors are known to fail early and leave you stranded again.
What to check
- Watch the tachometer while cranking. If the needle stays at zero while the engine cranks, the computer is likely not seeing the crankshaft signal.
- Note when the problem happens. Stalling only when hot and restarting after cooling is a classic sign of a failing crank sensor.
- Find the crankshaft sensor (often near the front of the engine by the crankshaft pulley, or at the back near the transmission) and inspect its connector and wiring.
- If you remove the sensor, look for metal debris or damage on its tip.
- A shop can view the sensor's signal while cranking to confirm whether the sensor, wiring, or reluctor ring is at fault.
Possible repairs
Replace the crankshaft position sensor
Replacing a failed sensor is often a reasonable job, though access varies a lot by vehicle.
Repair the wiring or connector
Fixing damaged wires or a corroded connector restores the signal without a new sensor.
Clean the sensor tip
If debris is the issue and the sensor tests good, cleaning it may help, though replacement is common.
Repair the reluctor ring
A damaged reluctor ring is a larger repair and usually a shop job.
Parts and tools that may help
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Frequently asked questions
Can a bad crankshaft sensor cause a no-start?
Yes. On many cars the engine cannot start without the crankshaft signal, because the computer does not know when to fire the spark plugs or injectors.
Can I drive with P0335?
Not if the car is stalling or hard to start. A stall in traffic is dangerous. If it runs normally, get it checked as soon as possible.
Why does my car stall when hot and restart when cool?
That is a classic sign of a failing crankshaft position sensor. The sensor stops working when it heats up and comes back once it cools.
Is P0335 the sensor or the wiring?
Either. The sensor is the most common cause, but damaged wiring, a corroded connector, or a damaged reluctor ring can cause the same code.
How much does it cost to fix P0335?
The sensor itself is usually moderately priced. Labor varies a lot depending on where the sensor sits on your engine.