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P0339

Crankshaft Position Sensor A Circuit Intermittent

The engine computer is losing the crankshaft position sensor signal at times. This can cause stalling, rough running, hard starting, or no-start problems. The issue is often a wiring, connector, sensor, or tone wheel problem.

Severity4/5 High
Can I drive?⚠ With caution

You may be able to drive short distances, but the engine can stall without warning or fail to restart. Avoid long trips and get it diagnosed as soon as possible.

DIY
$20–$120
Shop
$150–$500
Difficulty
intermediate

What It Means

P0339 means the powertrain control module detected an intermittent or unstable signal from crankshaft position sensor A. The PCM uses this signal to determine engine speed and crankshaft position for ignition and fuel control. If the signal drops out, the PCM may log a fault, disable spark or fuel briefly, and the engine may stall or not start.

Symptoms

Common Causes

1. Damaged, loose, or corroded crankshaft position sensor connector or wiringhigh
2. Failing crankshaft position sensorhigh
3. Oil, heat, or vibration damage to the sensor harness near the enginemedium
4. Crankshaft reluctor/tone wheel damage, contamination, or misalignmentmedium
5. Poor engine ground, low battery voltage, or charging system issuesmedium
6. PCM fault or calibration issuelow

Related Codes

FAQ

Is P0339 a serious code?

Yes. An intermittent crankshaft sensor signal can cause stalling, no-start problems, and sudden loss of power.

Can a bad battery cause P0339?

Yes. Low voltage or poor connections can disrupt the sensor signal or PCM operation.

Will replacing the crankshaft sensor always fix P0339?

No. Wiring faults, connector problems, tone wheel damage, and voltage issues can all cause the code.

Can P0339 cause a car to stall while driving?

Yes. If the signal drops out while the engine is running, the engine can stall.