If your check engine light is on and your scan tool shows P0335, you’re likely dealing with a problem in the crankshaft position sensor circuit specifically, no signal from the sensor. This isn’t just a warning code: it directly affects whether your engine can start or run reliably. Knowing the car crankshaft position sensor P0335 symptoms list helps you spot the issue early, avoid misdiagnosis, and get back on the road faster.

What does P0335 actually mean?

P0335 is an OBD-II trouble code that stands for “Crankshaft Position Sensor ‘A’ Circuit Malfunction.” It means the engine control module (ECM) isn’t receiving a valid signal from the primary crankshaft position sensor usually labeled Sensor A. That sensor tells the ECM where the crankshaft is and how fast it’s spinning. Without that data, the computer can’t time fuel injection or spark correctly. It’s not about wear alone; it could be a broken wire, corroded connector, damaged reluctor wheel, or a failed sensor.

What are the most common P0335 symptoms?

These symptoms often appear suddenly or intermittently especially when the engine is warm. Don’t wait for multiple signs to line up. If you see one or two of these, P0335 is worth checking:

• Engine cranks but won’t start no spark, no fuel pulse
• Stalling while driving, especially at idle or during low-speed maneuvers
• Rough idling or hesitation under light throttle
• Check engine light illuminated, often with no other drivability issues at first
• Intermittent no-starts the car starts fine one day, then refuses the next
• Loss of power or sudden RPM drop without warning

Note: Some vehicles may go into “limp mode” or default to a fixed timing value, which can mask the severity until the issue worsens.

Why do people confuse P0335 with other issues?

Because the symptoms overlap with problems like a bad camshaft sensor, ignition coil failure, or even fuel pump issues. For example, a no-start condition might lead someone to replace spark plugs or fuel filters first wasting time and money. But if the ECM isn’t seeing crankshaft rotation at all, those parts aren’t the root cause. You’ll often see similar behavior described in what happens when the crankshaft sensor speed signal is missing, since P0335 reflects exactly that loss.

What mistakes should you avoid when diagnosing P0335?

First, don’t assume the sensor itself is faulty. Over 40% of P0335 cases turn out to be wiring or connector issues especially near the sensor mounting point, where heat and vibration take a toll. Second, don’t clear the code and drive without verifying the signal is restored. The ECM may store pending codes before lighting the MIL, and intermittent faults can hide between drives. Third, skip visual inspection of the reluctor wheel (the toothed ring on the crankshaft or harmonic balancer). Missing or damaged teeth will prevent a clean signal and that’s not something a new sensor fixes.

How to confirm it’s really P0335 and not something else

Use a scan tool that reads live data, not just codes. Look for “CKP Sensor RPM” or “Engine Speed” while cranking. If it reads 0 RPM consistently even though the starter spins the engine that confirms signal loss. You can also check for continuity and resistance in the sensor circuit using a multimeter, and inspect the connector for bent pins or moisture. For deeper insight into how signal loss plays out across different makes and models, see our crankshaft sensor signal loss vehicle behavior analysis.

Can a bad crankshaft sensor cause intermittent no-starts?

Yes and it’s one of the most frequent reasons. The sensor may work when cold but fail as it heats up, or lose connection only when the engine vibrates at certain RPMs. That’s why some drivers report their car starts fine in the morning but refuses to restart after a short trip. This exact pattern is covered in detail in whether a bad crankshaft sensor causes intermittent no-start symptoms.

Next step: What to do right now

Before replacing anything, do this quick checklist:

1. Read the code again confirm it’s P0335, not P0336 (range/performance) or P0339 (intermittent)
2. Inspect the sensor connector and wiring harness for damage, corrosion, or loose pins
3. Check for oil or metal debris on the sensor tip common on engines with leaking front main seals
4. Verify the air gap between sensor and reluctor wheel meets factory spec (usually 0.020–0.080 in)
5. If possible, test the sensor’s resistance with a multimeter compare to your vehicle’s service manual spec

If all checks pass and the signal remains absent, replacement is likely needed. But remember: always rule out wiring and mechanical causes first. For official reference on P0335 definitions and testing procedures, consult the SAE J2012 standard.