What P0335 Means
P0335 means the crankshaft position (CKP) sensor circuit A has malfunctioned. The crankshaft position sensor is one of the most critical sensors on the entire engine — it's the PCM's primary reference for engine speed and exact crankshaft position, used to time ignition spark, fuel injection, and in many cases, to enable the engine to run at all. It works by reading a toothed reluctor ring on the crankshaft (or flywheel) as it spins, generating a signal pattern the PCM decodes into precise rotational position. A fault here — a dead signal, an erratic one, or one that drops out intermittently — can range from a rough-running engine to a complete no-start or a sudden stall while driving. Because the PCM cannot properly time ignition or injection without reliable crankshaft position data, this is treated as a high-severity code. An intermittent CKP fault is particularly concerning since it can cause the engine to stall unexpectedly at any speed, including on the highway, without warning.
Common Causes
- Failed or failing crankshaft position sensor no longer generating a clean signal
- Damaged, corroded, or disconnected CKP sensor wiring or connector
- Excessive air gap between the sensor and the reluctor ring due to a mounting issue
- Damaged or contaminated reluctor ring/tone wheel, often from metal debris or physical damage
- Wiring harness damage from heat, chafing, or age-related insulation breakdown near the sensor
- Weak or failing PCM connection/ground affecting sensor signal interpretation
Symptoms You Might Notice
- Check Engine Light on, sometimes only after an intermittent stall rather than continuously
- Engine cranks but won't start, or starts and immediately stalls
- Sudden stalling while driving, with no warning, particularly concerning at highway speed
- Rough idle or hesitation if the signal is intermittent rather than completely absent
- Engine may crank normally but simply never catch, since the PCM can't time spark or injection without this signal
What to Check First
- 1
Check the CKP sensor connector for corrosion, damage, or a loose pin, since this is a common and easily fixed cause
- 2
Use an oscilloscope or scan tool with live CKP data (if available) to check for a clean, consistent signal while cranking or running
- 3
Inspect the sensor's mounting and air gap against the reluctor ring, correcting if it's been disturbed during other engine work
- 4
Check for metal debris or physical damage on the reluctor ring/tone wheel itself, which may require removing covers to inspect directly
- 5
Test wiring continuity and resistance along the full circuit from sensor to PCM, checking for intermittent faults by wiggling the harness while monitoring the signal
Frequently Asked Questions
Can P0335 cause my car to stall without warning?
Yes, and this is one of the more concerning aspects of this code — an intermittent crankshaft position sensor fault can cause a sudden, unexpected stall at any speed, since the PCM instantly loses its ability to time ignition and injection the moment the signal drops out.
Why won't my car start with this code?
The PCM needs crankshaft position data to know exactly when to fire each spark plug and injector. Without a reliable signal, it often won't attempt to start the engine at all, or will crank without ever successfully firing.
Is the crankshaft position sensor expensive to replace?
The part itself is usually inexpensive to moderate in cost, but labor varies significantly depending on where it's mounted — some are easily accessible, while others require significant disassembly to reach, which affects the overall repair cost more than the part price does.
Reviewed by Emmanuel Erere, Auto Mechanic. Causes and diagnostic steps checked for workshop accuracy.