P0325: Knock Sensor Circuit Malfunction

What Does The P0325 Code Mean?

This diagnostic trouble code (DTC) is a generic powertrain code, which means that it applies to OBD-II equipped vehicles. Although generic, the specific repair steps may vary depending on make/model. Anecdotally this code seems to be more commonly found on Honda, Acura, Nissan, Toyota, and Infiniti vehicles.

A knock sensortells 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 be damaging to the engine if prolonged.

The computer uses this information to tune the engine so that it doesn’t knock. If your knock sensorwasn’t operating properly, so that it was always indicating a knock, the engine computer’s response may have been to change the ignition timing on your engine to help prevent damage.

Knock sensors generally bolt into or thread into the engine block. This P0325 code may show up intermittently or the Service Engine light may be lit constantly. Other knock sensor related DTC codes include P0330.

What Are The Symptoms Of The P0325 Code?

Potential symptoms of a bad knock sensor and/or a P0325 code may include:

• Illuminated Check Engine Light (malfunction indicator lamp)
• Lack of power
• Engine hesitation
• Engine detonation
• An audible pinging noise from the engine, especially while accelerating or under load
• Decreased fuel efficiency (increased consumption)

What Are The Potential Causes Of The P0325 Code?

A code P0325 most likely means one or more of the following has happened:

• The knock sensor is faulty and needs to be replaced
• There is a wiring short/fault in the knock sensor circuit
• The PCM powertrain control module is failed

How Can You Fix The P0325 Code?

• Check the resistance of the knock sensor (compare it to factory specs)
• Check for broken/frayed wires leading to the sensor
• Check for continuity in the wiring from the PCM to the knock sensor wiring connector
• Replace the knock sensor

TIP: It may be helpful to use a scan tool to read the freeze frame data. That is a snapshot of the various sensors and conditions when the code was set. This information could be helpful for diagnosis.

We hope you’ve 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 trouble.

Recommended Parts

Below are some recommended auto parts to help you address the trouble code affecting your vehicle and get it running smoothly again:

>>> Knock Sensor Parts
>>> Twippo 372Pcs Waterproof Wire Connectors Kit

Note: During the purchasing process, please check carefully whether the part you want to buy fits your car!

Check This Video For Reference

P0325 Infographic - 1 Minute Summary

Reference Sources

Diagnostic Trouble Code (DTC) Charts and Descriptions for P0325 – Page 59.