P2339 Fault Code

Cylinder 4 Above Knock Threshold

• What does that mean?
• Symptoms
• Causes
• Solutions

The P2339 fault code indicates that the engine control module (ECM) has detected that the signal from the knock sensor for cylinder 4 is higher than the predetermined knock threshold. This can suggest that engine knocking or pinging is occurring, which can lead to potential engine damage if not addressed promptly. Proper diagnosis is essential to determine the exact cause of the issue.

What are the symptoms of the P2339 code?

Symptoms that may accompany the P2339 code include:

• Engine knocking or pinging sounds, especially under load.
• Decreased engine performance and acceleration.
• Poor fuel economy due to improper timing adjustments by the ECM.
• Illuminated check engine light on the dashboard.

What causes the P2339 code?

Common causes of the P2339 fault code include:

• Faulty knock sensor for cylinder 4.
• Engine detonation or knocking due to incorrect timing, lean air-fuel mixture, or using low-quality fuel.
• Loose or damaged wiring and connectors associated with the knock sensor.
• Engine mechanical issues such as carbon buildup or a failing component that affects combustion.

How to fix P2339?

To resolve the P2339 fault code, consider the following steps:

• Inspect and replace the knock sensor for cylinder 4 if it's found to be faulty.
• Check and repair any wiring issues, ensuring connections are secure and free from corrosion.
• Perform a thorough inspection of the engine to identify any underlying mechanical issues causing knocking.
• Verify that the correct fuel grade is being used and that the air-fuel mixture is adequately balanced.