P0335 – Crankshaft Position Sensor A Circuit Malfunction

What does P0335 mean?

The crankshaft position sensor circuit is malfunctioning. This sensor tells the computer the exact position and speed of the crankshaft, which is essential for ignition timing and fuel injection. Without a usable signal, the engine may not run at all.

What causes P0335?

Listed from most to least common:

1. 1Failed crankshaft position sensor
2. 2Damaged wiring or connector
3. 3Debris or metal shavings on the sensor tip
4. 4Damaged reluctor/tone ring on the crankshaft
5. 5Incorrect sensor air gap after a previous repair
6. 6Failing sensor that only acts up when hot (very common)

Code breakdown

Common symptoms

• Check engine light on
• Engine cranks but will not start
• Sudden stalling while driving
• Intermittent stalling that worsens when the engine is hot
• Hard starting
• Rough running and misfires

How to diagnose

1. 1Inspect the sensor connector and wiring for damage or oil contamination.
2. 2Remove the sensor and check the tip for metal debris.
3. 3Measure sensor resistance against specification where applicable.
4. 4Check for RPM signal on a scan tool while cranking — no RPM reading during crank strongly indicates sensor or wiring failure.
5. 5Inspect the reluctor ring for damaged or missing teeth.
6. 6If the fault is heat-related, test the sensor when the engine is fully warm, since many fail only at temperature.

This can cause a no-start condition or sudden stalling while driving, which is a genuine safety concern. Address it promptly.

Common fixes and estimated costs

Costs are rough US estimates including parts and labor. Actual pricing varies significantly by vehicle, region, and shop rates.

Good to know

A classic pattern for this sensor is a car that runs fine cold, stalls once fully warmed up, then restarts after cooling down for 20–30 minutes. If that matches your symptoms, the sensor is very likely the cause even if it tests fine cold.

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