Knock Sensor 2 Circuit Range/Performance (Bank 2)
The P0331 code indicates that the Engine Control Module (ECM) has detected a malfunction in the knock sensor circuit for Bank 2 (the side of the engine not containing cylinder #1). The knock sensor detects engine knocking or pinging and sends a signal to the ECM to adjust ignition timing. This code is set when the sensor's signal is out of the expected range or performance parameters, often due to a faulty sensor, wiring issues, or incorrect installation.
01. Most Common Causes
- Faulty knock sensor (Bank 2)
- Damaged or corroded wiring/connector to knock sensor
- Incorrect sensor installation (e.g., overtightening or undertightening)
- Engine mechanical issues (e.g., excessive noise from worn components)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine performance and fuel economy
- Engine knocking or pinging noise, especially under load
- Possible hesitation or lack of power during acceleration
03. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for additional codes.
Step 2: Visually inspect the knock sensor and its wiring for damage, corrosion, or loose connections.
Step 3: Test the knock sensor's resistance and signal with a multimeter or oscilloscope per manufacturer specs.
Step 4: Check the sensor's torque specification and ensure it is properly installed.
Step 5: If necessary, replace the knock sensor and clear the code, then test drive to verify repair.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive with this code for extended periods as it can lead to engine damage from uncontrolled knocking. You may notice reduced performance and fuel economy.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for the part and labor, depending on vehicle make and model. DIY replacement can be cheaper if you have the tools.