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P2337 OBD-II Trouble Code: Cylinder #2 Above Knock Threshold

Check Engine Light

P2337 code definition

The P2337 trouble code signals a problem with the #2 cylinder being above the knock threshold.

What the P2337 code means

The P2337 code is a standard OBD-II trouble code that deals with the #2 cylinder being above knock threshold. The code will be detected when the powertrain control module (PCM) receives a voltage input reading from the knock sensor circuit for the #2 cylinder that deviates from the manufacturer’s reference by 10 percent or more.

What causes the P2337 code?

The P2337 trouble code can be caused by a few different things:

  • Malfunctioning cylinder knock sensor
  • Faulty wiring in the knock sensor
  • Broken or unplugged knock sensor connectors
  • Corroded knock sensor wires
  • More severe issue in the cylinder

What are the symptoms of the P2337 code?

When the P2337 trouble code is detected, the Check Engine Soon Warning Light will usually illuminate on the vehicle’s instrument cluster. The vehicle may also experience a lack of power, or unusual and delayed response when accelerating. A spark knock will usually be noticeable as well. The engine may experience more severe problems as well, which is a sign that there are other, more problematic trouble codes being detected as well.

How does a mechanic diagnose the P2337 code?

The first thing a reputable mechanic will do when diagnosing the P2337 code is identify the code with an OBD-II trouble code scanner. The mechanic will use the freeze frame data to assess the trouble code, and look for any additional codes. The codes should then be reset, and the car restarted and driven. If the codes do not return, it is likely that they were erroneously triggered, and there is no issue with the cylinder.

If the P2337 trouble code returns, then the mechanic will inspect the vehicle more thoroughly. The first thing the technician should do is assess the severity of any other present trouble codes. The P2337 code can be accompanied by more severe cylinder-related trouble codes. If this is the case, the P2337 code is likely the result of a larger issue, and the knock sensor for the #2 cylinder may be working properly when the rest of the system is. If the technician diagnoses more severe trouble codes, they should address those codes before the P2337 code.

If the P2337 code is the only trouble code present, or if the code remains even when other codes are addressed, the mechanic will check the wiring, connectors, and fuses associated with the knock sensor. If these components are in working order, the sensor itself will be inspected and replaced if needed.

After fixing the issue, the mechanic will then reset the P2337 and all accompanying trouble codes.

Common mistakes when diagnosing the P2337 code

The most common mistake made when diagnosing the P2337 code comes from not properly following the trouble code diagnosis protocol. Specifically, other codes should be looked for and addressed before the P2337 code, so that the actual issue can be fixed. Failure to reset the codes before inspecting the vehicle is another common mistake.

How serious is the P2337 code?

The severity of the P2337 code depends on whether or not there are other trouble codes present. If the P2337 code is the only trouble code, then the vehicle will still be drivable, though it won’t drive as well as it should. If the P2337 code is accompanied by other trouble codes, then there is likely a larger issue affecting the vehicle’s engine.

What repairs can fix the P2337 code?

There are a few fixes that are common for the P2337 trouble code:

  • Resetting the trouble codes and restarting the car
  • Replacing the wires, connectors, and fuses in the knock sensor
  • Replacing the knock sensor

Additional comments for consideration regarding the P2337 code

The wires and connectors on the knock sensor can be damaged by leaking oil in the vehicle. If the wires or connectors have any signs of oil on them, the technician should look for potential leaks to keep this issue from quickly returning.

In certain vehicles, knock sensors are placed in areas that are impossible to access without removing significant engine pieces. If this is the case, a mechanic should inspect all other potential issues to make sure that the knock sensor is the problem at hand before attempting to get to access the sensor.

Need help with a P2337 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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