Technical Description of OBD-II Trouble Code
The knock sensor in cylinder 2 has exceeded the threshold for vibrations.
Meaning of P2337
P2337 is a generic powertrain code that applies to many OBD-II vehicles (1996-newer), including Mercedes-Benz, Ford, Sprinter, Nissan, and others. The specific repair steps may vary depending on the year, make, model, and powertrain configuration.
If your vehicle has stored a code P2337 and the malfunction indicator lamp (MIL) is illuminated, it means that the powertrain control module (PCM) has detected a signal from the knock sensor in cylinder #2 that is outside of the acceptable range.
The knock sensor is responsible for monitoring excessive vibration and noise in an individual cylinder or bank of cylinders. It uses a chemical reaction to detect engine knock, which can be caused by timing, detonation, or internal engine failure. The knock sensor reacts to changes in engine noise by increasing voltage. Since it is part of a low voltage circuit, any changes in voltage are detected by the PCM.
If the PCM detects an unexpected level of voltage on the knock sensor circuit for cylinder two, it will store a code P2337 and illuminate the MIL. Multiple failure cycles may be required for the MIL to illuminate.
Severity of this DTC
When a P2337 code is stored, it is important to diagnose the cause as soon as possible. The symptoms associated with this code can range from minimal to catastrophic.
Symptoms of the Code
Symptoms of a P2337 trouble code may include:
Common Causes of the Code
Some common causes of the P2337 code include:
Troubleshooting Steps for P2337
Ensure that the engine has the correct oil level and is in good working order. Eliminate any actual engine noise, such as spark knock, before diagnosing a P2337 code.
To accurately diagnose a P2337 code, you will need a diagnostic scanner, a digital volt/ohmmeter (DVOM), and reliable vehicle information.
Search for technical service bulletins (TSBs) that match the stored code, vehicle information (year, make, model, and engine), and symptoms. TSBs can provide valuable information for a speedy diagnosis.
Connect the scanner to the vehicle diagnostic port and retrieve all stored codes and freeze frame data. Write down the information in case the code is intermittent. Clear the codes and test drive the vehicle until either the code is restored or the PCM enters readiness mode.
If the PCM enters readiness mode, the diagnosis may be more difficult because the code is intermittent. The condition that caused the P2337 code to be stored may need to worsen before an accurate diagnosis can be made. If the code is restored, continue with the diagnosis.
Use your source of vehicle information to obtain connector face views, connector pinout charts, component locator charts, wiring diagrams, and diagnostic flow charts specific to the code and vehicle in question.
Inspect the related wiring and connectors visually. Repair or replace any wiring that is cut, burned, or damaged. Replace spark plug wires and boots as part of scheduled maintenance. If the vehicle is overdue for a tune-up, suspect bad spark plug wires/boots as the cause of a stored P2337 code.
Before removing the knock sensor, disconnect the PCM and use the DVOM to check continuity in the knock sensor circuit. Take caution to avoid burns from coolant or oil when removing the sensor. Test continuity through the sensor and back to the PCM connector.
