Diagnostic manual index

obd2.help
AboutEspañol
OBD2.help›Powertrain›P0339

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.

SEV
4/5
DRIVE
CAUTION
DIY
$20–$120
SHOP
$150–$500

Quick answer

AI-CITATION READY

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.

Can you drive with it?

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.

Most common causes

  • Damaged, loose, or corroded crankshaft position sensor connector or wiring
  • Failing crankshaft position sensor
  • Oil, heat, or vibration damage to the sensor harness near the engine

Typical repair cost

DIY usually runs $20–$120. Typical shop repair lands around $150–$500, depending on the root cause.

01 / Definition

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.

02 / Drive status

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.

03 / Symptoms

  • Check engine light
  • Hard starting
  • No-start condition
  • Engine stalling
  • Rough idle
  • Misfires or hesitation
  • Poor acceleration
  • Tachometer dropping out or fluctuating
  • Intermittent loss of power

04 / Causes

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

05 / Diagnostic sequence

  1. 01Check for related codes, especially other crankshaft, camshaft, misfire, or voltage codes.
  2. 02Inspect the crankshaft position sensor connector for looseness, corrosion, oil intrusion, bent pins, or broken locks.
  3. 03Inspect the sensor wiring harness for rubbing, heat damage, stretching, or intermittent opens near the engine.
  4. 04Verify battery voltage, charging voltage, and engine grounds are within specification.
  5. 05Check live data or scope the crankshaft sensor signal while cranking and running to look for dropouts.
  6. 06Inspect the crankshaft reluctor/tone wheel for damage, debris, or excessive play.
  7. 07Test the sensor according to manufacturer procedures and replace it if the signal is unstable.
  8. 08If the wiring, sensor, and tone wheel test good, diagnose the PCM and related software updates.

06 / Repairs

1Clean, repair, or replace damaged crankshaft sensor wiring or connector$20–$150
2Replace a faulty crankshaft position sensor$30–$250
3Repair engine grounds, battery issues, or charging system faults$20–$300
4Repair or replace damaged crankshaft reluctor/tone wheel components$150–$800
5Update software or replace PCM if all other checks pass$0–$1,200

07 / Related codes

  • P0335
  • P0336
  • P0337
  • P0338
  • P0340
  • P0341
  • P0016
  • P0300

08 / 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.

09 / Source and method

DATA BASIS
OBD-II REFERENCE + OBD2.HELP
METHOD
STATIC VALIDATION
SAFETY
INFORMATIONAL

This page combines OBD-II diagnostic reference data with OBD2.help generated diagnostic guidance for code meaning, likely causes, and repair direction.

Publishing uses deterministic schema and build validation, plus manual spot checks on representative pages before release.

Safety-critical diagnosis and repairs should be confirmed with a qualified mechanic, especially when the vehicle is misfiring, overheating, or losing power.