P0339

Crankshaft Position Sensor A Circuit Intermittent

Ignition / crank position Generic OBD-II High

What it means

P0339 means the crankshaft position signal is cutting out intermittently. The ECM depends on it to time spark and fuel injection, so a signal that drops in and out typically shows up as random stalling, hard or no-starts, and rough running that come and go — often triggered by engine heat or vibration. It's worth fixing before it strands you.

High

Can I keep driving? Risky — an intermittent crank signal can cause sudden stalling or a no-start that leaves you stranded; fix promptly.

Real-world scan data

Seen in

984

scans in the past year

Found in

0.2%

of scans

0.3%

of scans that found faults

Appears alongside · share of P0339 scans

P0335in 65.8% of scans

P0016in 55.5% of scans

P0340in 54.1% of scans

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine light on
Intermittent stalling
Hard starting or an occasional no-start
Rough running or hesitation that comes and goes
Tachometer dropping out momentarily

Common causes

Most likely first

Failing crankshaft position sensor (often heat-sensitive)Likely
Loose or corroded connector, or chafed/damaged wiringCommon
Damaged reluctor/tone ring or metal debris on the sensor tipCommon
Wiring routed near heat or moving parts, cutting the signal intermittentlyLess often
Rarely, a failing ECMLess often

How to diagnose & fix

Work through it in order

Wiggle- and heat-test the sensor and harness while watching the RPM signal in live data.
Inspect the connector and wiring for chafing, corrosion, or a loose pin.
Check the sensor air gap and the tone ring for damage or debris.
Replace the crankshaft position sensor if the signal drops out.
Clear the code and re-test, including a hot restart.

FAQ

Quick answers

Is it safe to drive with P0339?+

Not really — an intermittent crank signal can cut spark and fuel without warning, causing a stall or no-start in traffic. Have it fixed before relying on the car.

Can I just clear P0339?+

Clearing it won't help; because the fault is intermittent it returns the next time the signal glitches. The sensor or wiring has to be repaired.

Read & clear P0339 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX