P0339
Crankshaft Position Sensor A Circuit Intermittent
When a vehicle powertrain module registers the fault code P0339, it points directly to an internal system malfunction identified as "Crankshaft Position Sensor A Circuit Intermittent". Operating your engine under this condition may degrade long-term fuel maps.
Driver's Summary
A P0339 fault code points directly to a problem with crankshaft position sensor a circuit intermittent that the ECM has confirmed over multiple drive cycles. Drivers typically experience engine dies randomly while driving, then restarts when this code is active. This is not a code to ignore — the underlying fault can rapidly worsen and lead to costly repairs if driving continues.
Symptoms
Engine dies randomly while driving, then restarts
Common Causes
- Loose electrical connection at sensor
- Frayed wiring shorting out
- Sensor failing when hot
- Excessive crankshaft end play
How to Fix
- 1 Clean and secure connector
- 2 Repair damaged wiring
- 3 Replace crankshaft position sensor
- 4 Measure crankshaft end play
Technical Explanation
Detection of P0339 occurs when the ECM cross-references multiple sensor inputs and determines that the reported values are physically inconsistent or out-of-range. Misfire rate is counted per cylinder over rolling windows and compared against two thresholds: a catalyst-damaging rate (triggers flashing MIL) and an emissions-exceeding rate (triggers solid MIL). The PCM logs which cylinder is misfiring based on crankshaft position at the time of each detected event. The fault remains stored in memory even after the MIL is cleared; it becomes a confirmed DTC after failing two consecutive drive cycles, and the PCM logs a freeze frame record of the engine's exact operating state at the moment of detection.
Is It Safe to Drive?
Driving with an active P0339 fault risks accelerating damage to loose electrical connection at sensor and related components. The longer the fault persists, the more expensive the eventual repair becomes — what starts as a sensor or solenoid issue can escalate to major mechanical failure.
Mechanic's Pro Tip
The most common mistake with P0339 is replacing the sensor without verifying the reference voltage and ground integrity first. Use a scan tool to monitor the sensor's live output; a truly failed sensor shows a stuck, flatlined reading — a sensor that fluctuates but reads slightly off usually indicates a wiring or vacuum issue, not a dead sensor. Always spray electrical contact cleaner on the connector pins before condemning the sensor.
Related Fault Codes
Frequently Asked Questions
What does OBD2 code P0339 mean?
OBD2 code P0339 refers to Crankshaft Position Sensor A Circuit Intermittent. When a vehicle powertrain module registers the fault code P0339, it points directly to an internal system malfunction identified as "Crankshaft Position Sensor A Circuit Intermittent". Operating your engine under this condition may degrade long-term fuel maps.
What are the most common symptoms of DTC P0339?
Drivers experiencing code P0339 typically report: Engine dies randomly while driving, then restarts.
Is it safe to drive with trouble code P0339 active?
Driving with an active P0339 fault risks accelerating damage to loose electrical connection at sensor and related components. The longer the fault persists, the more expensive the eventual repair becomes — what starts as a sensor or solenoid issue can escalate to major mechanical failure.
How much does it cost to fix code P0339?
The estimated repair cost for P0339 ranges from $100 to $400 USD. Sensor replacement: 150 - 350
Sensor replacement: 150 - 350
Need Professional Diagnostic Assistance?
Always verify sensor signals and wiring integrity with an OBD2 scanner before purchasing replacement parts.
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