P0339 critical

Crankshaft Position Sensor A Circuit Intermittent

The P0339 code means the vehicle's onboard diagnostic system has detected: Crankshaft Position Sensor A Circuit Intermittent. This is a critical severity code.

My Garage →

Keep driving?: Short distances only
DIY difficulty: hard
Estimated cost: $80 - $400 (parts and labor)

Recommended Tool

ANCEL AD310 OBD-II Scanner

Best-selling code reader on Amazon. Reads and clears check engine codes on any 1996+ vehicle. Under $30.

Check Price on Amazon

Affiliate link -- we earn a commission at no extra cost to you.

Every Tech Needs This

AstroAI Digital Multimeter

Essential for diagnosing sensor codes, checking voltage, and testing circuits. Under $15 and pays for itself on the first job.

Check Price on Amazon

Affiliate link -- we earn a commission at no extra cost to you.

Common Symptoms

Engine stalls intermittently
Random misfire events
Check Engine Light comes on and off
Momentary tachometer dropout
Hard starting after stall

Probable Causes (Ranked by Likelihood)

Loose or corroded CKP sensor connector Very High
Intermittent break in CKP sensor wiring High
CKP sensor failing under heat (thermal failure) High
Loose sensor mounting bolt causing vibration-induced signal loss Moderate
Reluctor ring with hairline crack causing intermittent signal gap Low

Step-by-Step Diagnostic Procedure

Wiggle-test the CKP sensor connector and wiring while monitoring RPM on a scan tool for dropouts
Test sensor resistance when cold and again at operating temperature -- a significant change indicates thermal failure
Verify the sensor mounting bolt torque -- a loose sensor vibrates and loses signal
Monitor CKP waveform with an oscilloscope during a road test to capture intermittent dropouts
If all electrical tests pass, inspect the reluctor ring closely for hairline cracks or damage

Frequently Asked Questions

Can I drive with code P0339?

You can drive short distances with extreme caution. The engine may stall unpredictably, including at highway speeds. This is a safety concern and should be repaired immediately.

Why does my engine only stall when hot?

Heat-related CKP sensor failures are very common. The internal components of the sensor expand when hot, causing an intermittent open circuit. The engine works fine when cold and stalls after reaching operating temperature.

Can I temporarily fix an intermittent CKP issue?

There is no reliable temporary fix. If the connector is loose, securing it may help temporarily. However, a failing sensor or damaged wiring requires replacement for a permanent repair.