P0325 – Meaning, Causes, Symptoms, & Fixes

Code P0325 Definition

Knock Sensor 1 Circuit Malfunction (Bank 1)

Code P0325 Meaning

Knock sensors are solely used for the purpose of sensing when your engine is “knocking,” or sensing when there is exploding in the air/fuel mixture in a way that delivers less power and can also damage the engine if prolonged. When the engine “knocks” there is an excessive amount of NOx that is released. When trouble code P0325 is set, this means that the knock sensor 1 in Bank 1 is not operating properly.


  • Check Engine Light
  • Loss of engine power
  • No noticeable drivability issues


  • Faulty sensor 1 Bank 1 knock sensor
  • Engine is running excessively lean
  • Faulty or damaged knock sensor wiring
  • Engine coolant system fault

Code P0325 Severity – Low   

There are no driveability concerns with trouble code P0325. However, along with all Diagnostic Trouble Codes, there should be a sense of haste in getting this repaired so that there is no further damage to the engine.

Code P0325 Common Diagnosis Mistakes

There are times where the engine/fuel coolant system are the issue and replacing the knock sensor immediately will not make the Check Engine Light turn off.

Code P0325 Diagnosis Steps

  • Tools Needed to Diagnose:
    • FIXD
    • Live freeze frame data (Found on FIXD App with Sensor)

How To Diagnose P0325

  1. Check to see if there are any other codes along with P0325 and clear your Check Engine Light with FIXD
  2. Test drive the vehicle and attempt to replicate the driving conditions that will also give similar if not the same freeze frame data in an attempt to pinpoint the issue.
  3. Is the knock sensor sending a signal to the PCM? If so, there may be an issue with the coolant temperature readings. If not, the knock sensor may need to be replaced (Step 5).
    1. If there are issues with the coolant temperature readings, deal with them ASAP because an overheated engine can definitely cause the engine to knock.
  4. Conduct a visual inspection of the knock sensor wiring, and any connections to the knock sensor to make sure there are no signs of disconnection, tearing, etc.
  5. If the conclusion is that the knock sensor needs to be replaced, then it is often recommended to replace not only the sensor but the knock harness as well.

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Comments 8


November 11, 2018

I change my knock sensor but my car us still doing the samething


November 15, 2018

So do I. I changed it 3 times ,and it still comes out.

Conrad Duenas

November 21, 2018

I chance the knock sensor and the light still showing on the dashboard, and on the fixd sensor still telling me the I have knock sensor malefunction problem. Can’t fixed

Odell Steen

June 8, 2019

I have the same issue


November 28, 2018

i have nissan fb 15 on machine diagnosis the crank and knock sensor were recorded malfunction after replacing the two sensors the machine is still reading crank and knock sensor even after erasing the error.also the engine is losing power could it be linked to faulty gas regulator.

Robert Mack

December 22, 2018

My problem is I can’t find it and can someone tell where it is on motor it’s an 08 Saturn vue 3.5l gm motor


February 26, 2019

Its behind the right side catalytic converter..you have to remove it along with other stuff to gain access


May 9, 2019

I have a 2002 bmw 325i with three codes showing:

Could one of theses codes cause the other codes to appear?

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