P0335: Your engine's crankshaft position sensor signal is missing or unreliable
Crankshaft Position Sensor "A" Circuit Malfunction
The engine computer lost the crankshaft position signal. The engine can cut out without warning, taking power steering and brake assist with it. Get it checked today. If it has stalled, have it towed.
Stop driving and get help if
- The check engine light is flashing
- The temperature gauge runs high, or you see steam (overheating)
- The car loses power, hesitates badly or stalls
- You smell burning or see smoke
- A brake warning light comes on, or the brakes feel different
Pull over as soon as you can, turn the engine off, and call a tow or roadside help.
What it means
The crankshaft position sensor tells the computer how fast the engine is turning and where the crankshaft is. The computer uses that to time the spark and the fuel. The sensor reads teeth on a ring that spins with the crankshaft and sends out a pulsing signal. When those pulses go missing or turn garbled, usually caught while cranking or running, the computer sets P0335. Because this signal is what makes spark and fuel happen, a hard failure often means the engine cranks but will not start. The classic pattern is a stall when the engine is hot, then a restart once it cools.
Common causes
- Failed crankshaft position sensorThe most common fix. Often heat-related and intermittent: stalls when hot, restarts after cooling.
- Damaged wiring or connector in the sensor circuitChafed harness near exhaust heat, corroded or oil-soaked plug, spread terminals, or a broken wire inside good insulation.
- Cheap aftermarket sensor that is bad out of the boxNon-OEM crank sensors often fail fast. Nissan and Honda are especially picky. This makes P0335 come back after a repair.
- Damaged or slipped reluctor (tone) ring, or wrong sensor air gapA cracked, missing, or slipped tooth ring, common on high-mileage GM V6s. Or a gap set out of spec after install.
- Broken or jumped timing belt or chainThe crank turns but the computer sees no valid crank signal. Rare, but rule it out first on interference engines before cranking again.
- Computer fault, bad ground or low voltage, or a skipped relearnRare. On GM, skipping the crank variation relearn sets P1336. Never replace the computer until the sensor, wiring, and ring check out.
What the fix could involve
From the cheaper fix to the bigger one. Prices depend on your car, your area and the shop, so ask for a written quote that names the part and the labor before you approve it.
- Crankshaft position sensor replacement, easy-access location
- Sensor part only if you do it yourself
- Wiring or connector diagnosis and repair
- Sensor replacement, hard-access (buried behind timing cover or in the block)
- Reluctor (tone) ring replacement, worst case
Symptoms
- Check engine light on, sometimes the only sign at first
- Engine cranks but will not start
- Stalling while driving, classically when the engine is hot, then restarts after it cools
- Rough idle and misfiring
- Hesitation or loss of power when you accelerate
- Tachometer reading erratic or dropping to zero
What to do next
Do not just throw a sensor at it, which is how people pay twice. First spend five minutes on the cheap check. Unplug the sensor connector and look for corrosion, oil, and loose terminals. Then trace the harness where it runs near the exhaust and engine mounts for chafed or chewed wire. Bad wiring causes a large share of the "replaced it and the code came back" jobs. If the sensor needs replacing, buy OEM, not the cheapest part, which often arrives dead or dies in weeks. On GM, Chrysler, and some Honda, run a crank relearn after replacing, or you get P1336 and disabled misfire detection.
Lewis reads P0335 alongside live engine RPM and related crank and cam codes, so you can watch whether the RPM signal cuts out. Get Lewis on the App Store or Google Play.
Related codes
FAQ
- Will a P0335 code stop my car from starting?
- It can. This sensor is what tells the computer to make spark and fuel. When the signal is fully lost, the engine cranks but will not start. When it is intermittent, the car may start fine, then stall later, often once the engine gets hot.
- I replaced the crankshaft position sensor but P0335 came back. Why?
- Two common reasons. The sensor circuit has damaged wiring or a bad connector you did not fix. Or the new sensor is a cheap aftermarket part that failed fast. Buy OEM. On GM and some Chrysler and Honda vehicles, you also must run a crank relearn after replacing it.
- How much does it cost to fix code P0335?
- A wiring or connector fix is the cheaper end. A sensor that is easy to reach is next. A sensor buried behind the timing cover or in the block costs more in labor, and a damaged tone ring is the worst case. Ask for a written quote that names the part and the labor.
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