P0331 Fault Code

Knock Sensor 2 Circuit Range/Performance (Bank 2)

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

The P0331 fault code indicates an issue with the knock sensor 2 circuit performance or range for Bank 2 of the engine. The knock sensor is crucial for detecting engine knock (pre-detonation) to help the engine control module (ECM) adjust ignition timing and optimize performance. When the circuit for this sensor experiences issues, it can lead to poor engine performance and increased emissions.

What are the symptoms of the P0331 code?

Drivers may notice various symptoms when the P0331 code is triggered, including:

• Reduced engine performance or power.
• Increased fuel consumption due to improper fuel adjustment.
• Engine knocking noise (pinging) under load.
• Check Engine Light illuminated on the dashboard.
• Engine misfires or running rough in some cases.

What causes the P0331 code?

Several factors can lead to a P0331 code, including:

• Faulty knock sensor: The sensor itself may be defective.
• Electrical issues: Damaged wiring, loose connectors, or short circuits in the knock sensor circuit.
• Engine mechanical issues: Problems such as abnormal engine vibrations or improper combustion can affect the knock sensor’s readings.
• ECM failure: In rare cases, a malfunctioning engine control module can incorrectly report a fault.

How to fix P0331?

To resolve the P0331 code, the following steps can be taken:

1. Inspect the knock sensor and its wiring for damage or poor connections.
2. Test the knock sensor with a multimeter to verify its proper operation.
3. Check for and repair any related engine mechanical issues if present.
4. If the sensor and wiring are in good condition, consider reprogramming or replacing the ECM if it's determined to be the source of the problem.
5. Clear the fault codes and conduct a test drive to ensure the issue has been resolved.