P0339 medium Severity

P0339: Crankshaft Position Sensor "A" Circuit Intermittent

Intermittent loss of crankshaft position signal can cause rough running, stalling, hard starts, or no-start situations.

Overview

P0339 diagnostic trouble code indicates an intermittent circuit fault in the crankshaft position sensor A signal, often due to electrical issues, sensor faults, or connection problems.

Common Symptoms

  • Check Engine Light illuminated intermittently or steady
  • Engine may stall or shut off unexpectedly
  • Difficulty starting or no start at all
  • Rough idle or misfires
  • Reduced engine performance and fuel efficiency

Most Common Causes

Faulty crankshaft position sensor high

Sensor internal failure leading to erratic signal output under vibration or heat.

Damaged or corroded wiring harness/connectors high

Intermittent connection due to corrosion, chafed wires, or loose terminals.

Poor electrical connection or ground issue medium

High resistance in connector or ground can intermittently disrupt signal.

Faulty PCM/ECM input circuit low

Rare but possible if all sensor and wiring tests are within specification.

Reluctor ring damage or excessive air gap low

Mechanical sensor target damage can cause intermittent readings.

Diagnostic Steps

  1. Connect an OBD-II scanner and verify stored codes including P0339 and any related codes.
    Expected: P0339 present, check for additional codes indicating sensor or timing issues.
    Interpretation: Confirms relevant DTC and related system faults prior to further troubleshooting.
  2. Perform a visual inspection of the crankshaft position sensor wiring and connectors.
    Expected: Check for broken wires, corrosion, loose or damaged connectors.
    Interpretation: Any physical damage here can explain intermittent circuit behavior.
  3. Measure sensor signal with a multimeter/oscilloscope while cranking the engine.
    Expected: Steady voltage or waveform signal; intermittent dropouts indicate fault.
    Interpretation: Intermittent or absent waveform suggests sensor or wiring issue.
  4. Check resistance of the CKP sensor against OEM specifications.
    Expected: Resistance in specified range; out of range indicates internal sensor fault.
    Interpretation: Out-of-spec resistance typically means sensor replacement is required.
  5. Wiggle test wiring and connectors during live data monitoring.
    Expected: No change in signal when moving wiring; signal drops indicate wiring/connectors.
    Interpretation: Helps isolate intermittent wiring issues.
  6. If sensor and wiring are good, test ECM input circuit or consider re-programming.
    Expected: ECM correctly processes signals from other sensors; if not, module issue possible.
    Interpretation: Rare, but confirms ECM involvement when external components test OK.

Repair Solutions

Replace crankshaft position sensor medium
Estimated Cost: $100 - $350

Part cost varies by vehicle; replacement often resolves intermittent signal faults.

Repair or replace damaged wiring/connectors medium
Estimated Cost: $50 - $150

Cleaning corrosion and securing connections can often fix intermittent issues.

ECM re-programming or replacement hard
Estimated Cost: $400 - $1500

Consider only when sensor and wiring are validated good.

Inspect/repair reluctor ring or sensor mounting if mechanically damaged hard
Estimated Cost: $200 - $800

Less common; requires deeper engine access.

Common Misdiagnoses

Avoid these common diagnostic mistakes:

  • Assuming a timing belt or cam timing issue without checking sensor circuit first
  • Replacing the crankshaft sensor without inspecting wiring/connectors

Frequently Asked Questions

What does the P0339 code mean?

Crankshaft Position Sensor "A" Circuit Intermittent is the standard definition for P0339. This diagnostic code is triggered when the ECU detects a problem in the Ignition.

Reflecting on severity: How bad is P0339?

The P0339 code is considered medium severity. Intermittent loss of crankshaft position signal can cause rough running, stalling, hard starts, or no-start situations.

Symptoms associated with DTC P0339

Common symptoms include: Check Engine Light illuminated intermittently or steady, Engine may stall or shut off unexpectedly, Difficulty starting or no start at all. You might also notice the Check Engine Light is on.

What causes the P0339 code?

It can be caused by several factors, most notably: Faulty crankshaft position sensor, Damaged or corroded wiring harness/connectors, Poor electrical connection or ground issue.

Is P0339 expensive to fix?

Expect to pay around $150 if the issue is a Repair or replace damaged wiring/connectors, but up to $1500 if the ECM re-programming or replacement needs replacement.

Does P0339 affect Ford, Toyota, or Honda?

P0339 is not specific to any one brand. It can appear on Ford, Dodge, Toyota, Honda, Jeep, and other vehicles.

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