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P0325 OBD-II Trouble Code: Knock Sensor Malfunction (Sensor 1, Bank 1)

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P0325 code definition

Knock Sensor Malfunction (Sensor 1, Bank 1)

What the P0325 code means

P0325 is a general ODB2 diagnostic trouble code associated with the knock sensor circuit. This code may be seen with other knock sensor codes and lean condition codes.

P0325 means that there is a malfunction within the knock sensor 1 in circuit bank 1. This malfunction will be detected by the ECU when it does not receive the proper information from the knock sensor. This triggers a Check Engine Light to be illuminated on the dashboard.

What causes the P0325 code?

  • A failed ECU
  • A failed knock sensor
  • Open or short in the wiring harness
  • Electrical connection issues

What are the symptoms of the P0325 code?

  • The Check Engine Light illuminating on is normally the most noticeable symptom.
  • The engine may have a slight lack of power.
  • There may be no felt symptoms with P0325.

How does a mechanic diagnose the P0325 code?

  • Uses a scan tool to check for any codes, there may be history, pending and current codes

  • Notes the freeze frame data for each of these codes this will show the conditions the vehicle was under when the code was set such as engine RPM, coolant temp, run time, and vehicle speed

  • Clears the code to have a fresh start to diagnosis

  • Performs a road test to try to get the Check Engine Light to come back on and confirm the issue is present

  • Uses a scan tool to check for proper knock sensor operation while the engine is revved

  • Checks the resistance of the knock sensor

  • Tests the ECU test following the manufacturer's testing procedures if needed.

Common mistakes when diagnosing the P0325 code

With any code, even the most experienced technician can make simple mistakes and overlook the basics if they do not follow all of the diagnostic steps or do not complete them in order.

How serious is the P0325 code?

P0325 is generally not a serious code and should be able to be driven without issue to a safe location once the malfunction occurs. Some vehicles may experience a slight lack of engine power as the ECU will retard timing to prevent damage in case the engine was knocking.

What repairs can fix the P0325 code?

  • Replacing the ECU
  • Repairing or replacing the wiring harness
  • Replacing a faulty knock sensor
  • Repairing an electrical connection

Additional comments for consideration regarding the P0325 code

A scan tool that does more than just check codes will be needed for performing accurate diagnosis of P0325. Many of the items that are checked can be done much faster and more accurately with the live data stream these scan tools allow access to.

Need help with a P0325 code?

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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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