Error Code P0330 is defined as Knock Sensor 2 Circuit Malfunction (Bank 2). This code is set when there’s a malfunction detected in the knock sensor 2 circuit that’s causing it to operate incorrectly.

This code is a generic trouble code, which means it applies to all vehicles equipped with OBD-II, particularly vehicles made since 1996 up to present. Specifications on the definition, troubleshooting, or repairs of course, vary from one make/model to another.

Definition

Knock sensors are usually bolt into or thread into the engine block. They work by sending a message to the PCM (powertrain control module, or also known as ECM or engine control module in some makes) when one or more of the cylinder of the engine is ‘knocking.’ This means air/fuel mixture exploding in a way that delivers far less power and exposes the engine to risk of damage if prolonged. The PCM then uses this information to fine tune the engine so it will stop from knocking. If the knock sensor is not working properly, and it’s always indicating a knock, the PCM will then response to change the ignition timing of the engine.

Error Code P0330 is set when this happens, which simultaneously triggers the check engine light.

Common Symptoms

Error Code P0330 causes drivability problems, such as lack of power and even hesitation. Other common symptoms include:

  • Engine pings on acceleration
  • Engine running hotter than normal

In some rare cases, the engine may not exhibit any noticeable symptoms.

Possible Causes

Error Code P0330 is usually caused by multiple factors, such as:

  • Faulty B knock sensor
  • Short or fault in the wiring of the knock sensor circuit
  • Poor electrical connection for knock sensor harness
  • Open or short in the knock sensor wiring harness
  • Excessively lean condition
  • Faulty engine coolant system
  • Failed PCM (rare)

How to Check

As with other error codes, technicians start their diagnosis of this error code with the help of the scan tool. They check the vehicle’s DLC port and gather all codes present as well as the freeze frame data when the codes were set.

The codes are then cleared and the vehicle is taken for a test drive, under the same conditions as per the freeze frame data to duplicate the fault.

The technician will then conduct a visual inspection for the wirings, damaged components or any apparent damages on the system.

The technician will then use the scan tool to see live data stream as the vehicle runs; it’s important that the technician see the situation in the engine coolant temperature and fuel trims to make sure there are no lean faults or cooling system faults are present.

Then, the scan tool will be used to check the knock sensor operation.

Lastly, technicians will test the PCM for any present faults.

How to Fix

Repair for this error code is pretty easy and straightforward, and some of the most common repairs are:

  • Repair or replacement of short in wiring harness
  • Repair of any connection issues
  • Replacement of faulty knock sensor
  • Lean condition repair
  • Resolving issues on the engine coolant system
  • Replacement of PCM (rare)

Error Code P0330 neither usually cause serious drivability problems, nor keep drivers from driving the vehicles safely. It does however, will cause the vehicle to fail emission testing in many states, which can cause huge hassle.