P0335 Code: Crankshaft Position Sensor 'A' Circuit Malfunction
The engine computer is not receiving a usable signal from the crankshaft position sensor, which tracks crankshaft speed and position — the reference for ignition and fuel-injection timing.
What this means for driving
This is one of the more disruptive sensor faults: without a crankshaft signal the engine may stall without warning or refuse to start at all. Stalling in traffic is a safety concern in itself, so if the engine is stalling or will not restart reliably, stop driving it and arrange a tow.
When in doubt, have a mechanic assess it promptly. If any of the red-flag symptoms below are present, stop driving and arrange a tow rather than risking it.
Important: This page is general information only — not professional mechanical advice and not a diagnosis for your specific vehicle. Fault causes and severity vary by make, model, year, and condition. A qualified mechanic should confirm any diagnosis before you make driving decisions or authorize repairs.
Red-flag symptoms: stop and get help
- Engine stalls and will not restart
- Repeated stalling while driving
- Tachometer dropping to zero while the engine is running
Symptoms of P0335
- Engine will not start or takes long cranking to start
- Engine stalling, sometimes without warning
- Misfiring or rough running
- Tachometer behaving erratically
- Check-engine light on
Most likely causes, ranked
- Faulty crankshaft position sensor — the most common cause
- Damaged wiring or connector to the sensor
- Damaged reluctor ring (the toothed wheel the sensor reads)
- Sensor gap out of specification after nearby work
How a mechanic diagnoses it
- Sensor signal checked while cranking with a scan tool or oscilloscope.
- Wiring and connector inspected; sensor resistance compared with specification.
- Reluctor ring inspected if the sensor and wiring test good.
Likely fixes
- Replace crankshaft position sensor
- Repair wiring or connector
Repair costs vary by vehicle, region and shop. Get a quote from a local mechanic.
Related codes
- P0340: Camshaft Position Sensor 'A' Circuit Malfunction (Bank 1)
- P0300: Random/Multiple Cylinder Misfire Detected
CheckMyCarCode content is general information only and is not a substitute for professional diagnosis. Trouble-code meanings are standardized for generic (P0xxx) codes, but causes, severity, and repairs vary by vehicle. If your car shows a red-flag symptom, stop driving and get professional help.