Crankshaft Position Sensor A Circuit Intermittent
The P0339 code indicates an intermittent signal from the crankshaft position sensor (CKP) circuit. The CKP sensor monitors engine speed and position, sending this data to the ECU for ignition timing and fuel injection. An intermittent fault means the signal drops out or becomes erratic, often due to wiring issues, sensor damage, or connector problems. This can cause misfires, stalling, or no-start conditions.
01. Most Common Causes
- Faulty crankshaft position sensor
- Damaged or corroded wiring/connectors
- Intermittent short or open in circuit
- Crankshaft reluctor ring damage
- ECU issues (rare)
02. Symptoms You Will Notice
- Engine misfire or rough running
- Intermittent stalling
- Hard starting or no start
- Check Engine Light on
- Reduced fuel economy
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect CKP sensor wiring and connector for damage or corrosion.
Step 3: Test sensor resistance and AC voltage output while cranking.
Step 4: Check for intermittent signal using a lab scope or graphing multimeter.
Step 5: Inspect reluctor ring for damage or debris.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
Not recommended. The vehicle may stall unexpectedly, posing a safety risk. Have it diagnosed promptly.
How much does it cost to fix?▼
Typically $50-$150 for a DIY sensor replacement; labor adds $100-$200 at a shop.