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P0330 Code – What Does It Mean & How To Fix It

This is one of the most frequent OBD2 trouble codes. Read the full article below to know what it means, how to fix it, and what other codes may show related to it.


P0330 is an OBD-II Code that refers to Knock Sensor 2 Circuit Malfunction (Bank 2)


A P0330 code is caused by an ECM (Engine Control Module) receiving a signal detecting that the Knock Sensor 2 Circuit has had a Malfunction on Bank 2 and is not sending the right signal back to the ECM. This causes the system to store a code and turn on the Check Engine Light.


Common causes for this code include:

  • Faulty Knock Sensor 2 
  • Damaged Knock Sensor 2 Wiring
  • Coolant leak in the engine coolant system
  • Loose or Damaged Harness Connections 
  • Faulty ECM 
  • Excessively lean condition


The symptoms of a P0330 code are:

  • MIL (Malfunction Indicator Lamp) Illumination
  • Engine Running Rough
  • Poor engine performance
  • Rough idle 
  • Loss of power 
  • Hesitation during acceleration 
  • Stalling or Stumbling on acceleration 
  • Crank no start condition due to timing issues or other problems


To diagnose a P0330 DTC code, a technician would:

  1. Scan for codes in the ECM and look at the freeze frame data to determine when the P0330 code is set. 
  2. Confirm that there are no other codes in ECM to indicate a different problem.
  3. With a scan tool, monitor Knock Sensor 2 Circuit readings while driving at various speeds and engine loads. If there are unusual knock sensor 2 readings, inspect all wiring, ground connections, and connectors associated with Knock Sensor 2 Circuit to make sure they are within specifications before replacing them or rechecking their function to ensure that the circuit is not shorted or open.
  4. Check for vacuum leaks and fuel system problems that may contribute to the code being set by performing a visual inspection while monitoring knock sensor 2 signal readings during idle and while driving under various conditions. Repair as necessary.
  5. Test drive the vehicle to see if the same symptoms are present, or whether any new ones have appeared.

Common mistakes

The following are some of the most common mistakes that a technician may make when diagnosing a P0330 code:

  • Not checking the freeze frame data in the ECM to determine when the P0330 code set.
  • Not recognizing that multiple codes in the ECM may indicate a different problem.
  • Failing to monitor knock sensor 2 circuit readings while driving at various speeds and engine loads with a scan tool before replacing components or rechecking their function for this code.
  • Not checking the Knock Sensor 2 circuitry for shorted or open circuits before replacing components.
  • Failing to test drive the vehicle after making repairs to see if they fixed the problem, or whether new problems have appeared since repairing them.

How serious is this?

A P0330 code usually is not considered an emergency, since the vehicle can usually be driven to a safe location before it stalls or fails. But some codes should be repaired as soon as possible so they do not compound into other more serious problems that require major engine disassembly for repair.

What repairs can fix the code?

The following are solutions that may fix this problem:

  • Replacing the ECM (Rare)
  • Replacing Knock Sensor 2
  • Repairing the coolant system leak 
  • Replacing or repairing damaged wiring or connectors on Knock Sensor 2 Circuit 
  • Improving Wiring Connections to correct intermittent malfunctions.
  • Fixing a Lean Condition

Related codes

A P0330 is related to and may be accompanied by the following codes:

P0325 – Knock Sensor 1 Circuit Malfunction (Knock Sensor 1)

P0335 – Knock Sensor 2 Circuit Malfunction (Knock Sensor 2)

P0420 – Catalyst System Efficiency Below Threshold (Bank 2)

P0440 – Evaporative Emission Control System Leak Detected (Fuel Cap/Hose)

P0441 – Evaporative Emission Control System Incorrect Purge Flow


In conclusion, the P0330 code is a generic trouble code that means the computer has detected an issue with the Knock Sensor 2 Circuit Malfunction (Bank 2) and that the driver should have the problem diagnosed and repaired when possible. The engine may run rough, lose power, hesitate during acceleration, stall or stumble on acceleration, and crank over but not start due to timing issues or other problems until it is corrected.