DTC P0333 Knock Sensor 2 Circuit High Input

In the world of automotive diagnostics, understanding On-Board Diagnostic Trouble Codes (DTCs) is crucial. Today, we’re focusing on DTC P0333, specifically the Knock Sensor 2 Circuit High Input issue. In this comprehensive guide, we will decode the meaning of P0333, explore its symptoms, investigate potential causes, discuss systematic diagnosis, and provide effective solutions for fixing this trouble code. Let’s dive right in.

1. What does P0333 code mean?

DTC P0333 is a diagnostic trouble code that indicates a high input signal in the Knock Sensor 2 Circuit. The knock sensor’s primary function is to detect abnormal engine vibrations or knocking sounds. When it detects a high input signal, the Engine Control Module (ECM) triggers the P0333 code, signifying a problem with the sensor or its circuit.

2. What are the causes of DTC P0333?

Understanding the potential causes of DTC P0333 is fundamental to effective troubleshooting. These causes may include:

  • A malfunctioning knock sensor.
  • Damaged or frayed wiring in the Knock Sensor 2 Circuit.
  • Loose or corroded electrical connections.
  • Engine mechanical issues, such as excessive carbon buildup.

Identifying the root cause is the initial step in resolving this problem.

3. What are the symptoms of DTC P0333?

Recognizing the symptoms associated with DTC P0333 is crucial for early detection. Common signs of this issue include:

  • Reduced engine performance.
  • Poor fuel efficiency.
  • An illuminated check engine light (CEL) on the dashboard.
  • Abnormal engine knocking or pinging noises.

If you experience any of these symptoms, it’s essential to address the problem promptly to prevent further damage.

4. How to diagnose DTC P0333?

Accurate diagnosis of DTC P0333 requires a systematic approach. Here’s a step-by-step guide:

If everything appears normal so far, consider conducting a comprehensive inspection of the engine components that can cause abnormal knocking.

5. How to fix DTC P0333 problem?

Once you’ve identified the issue causing DTC P0333, it’s time to address it effectively. Here are some steps to consider:

  • Replace a faulty knock sensor if necessary.
  • Repair or replace damaged wiring and connectors in the Knock Sensor 2 Circuit.
  • Address any underlying engine mechanical issues, such as excessive carbon buildup.
  • Clear the trouble code using your OBD-II scanner after completing repairs.

Clearing the trouble code is crucial to reset the check engine light and confirm that the problem has been successfully resolved.


In this comprehensive guide, we’ve tackled DTC P0333, the Knock Sensor 2 Circuit High Input code. Understanding its meaning, symptoms, potential causes, systematic diagnosis, and the importance of clearing the trouble code empowers you to address this issue confidently. Whether you’re an automotive enthusiast or a professional mechanic, resolving these problems with precision and expertise not only restores your vehicle’s performance but also enhances your automotive knowledge. Safe and smooth travels!