What does it mean?
This diagnostic trouble code (DTC) is a generic powertrain code, meaning it applies to vehicles equipped with OBD-II. Although generic, specific repair steps may vary by make/model. Interestingly, this code appears to be more common on Honda, Acura, Nissan, Toyota, and Infiniti vehicles.
A knock sensor tells the engine computer when one or more of your engine’s cylinders are “knocking” – that is, exploding the air/fuel mixture in a way that delivers less power and can damage the engine if prolonged.
The computer uses this information to adjust the engine so it doesn’t knock. If your knock sensor wasn’t working properly, so it was always indicating knock, the engine computer’s response may have been to modify your engine’s ignition timing to prevent damage.
Knock sensors typically bolt or screw into the engine block. This P0325 code may appear intermittently or the Service Engine light may be on continuously. Other DTCs associated with knock sensors include P0330.
Here’s an example of a typical knock sensor:
What are the symptoms of a bad knock sensor?
Potential symptoms of a bad knock sensor and/or P0325 code may include:
Check Engine light illuminated (malfunction indicator lamp)
lack of power
engine hesitation
engine detonation
audible knocking noise from the engine, particularly during acceleration or under load
reduced fuel efficiency (increased consumption)
What causes a P0325 code?
A P0325 code most likely means one or more of the following events has occurred:
The knock sensor is faulty and needs replacement
There’s a short circuit/wiring fault in the knock sensor circuit
The Powertrain Control Module (PCM) is malfunctioning
Possible solutions
Check the knock sensor’s resistance (compare to factory specifications)
Check for broken/frayed wires leading to the sensor
Check continuity of wiring from PCM to knock sensor wiring connector
Replace the knock sensor
TIP: It may be helpful to use a scan tool to read freeze frame data. This is a snapshot of various sensors and conditions when the code was set. This information could be useful for diagnosis.
We hope you found this P0325 information helpful. If you need further assistance, please browse the related forum discussions below or join the forum to ask a question directly specific to your issue.