Services
Insurance
Loans
Repairs
Advice
About

How do you test a knock sensor to see if it’s not working?

I ran an OBD-II scan on my car’s computer, and it came back with code P0325. The wiring doesn’t look damaged from what I can tell, but I don’t know how to test a knock sensor to see if it’s working or not. Could you guys tell me how to test a knock sensor?

avatar
Matt Terzi · Updated on
Reviewed by Shannon Martin, Licensed Insurance Agent.
You’re right, code P0325 refers to a bad knock sensor. It could result from damaged wiring, but testing the knock sensor is the best way to go here.
Engine knock happens when fuel burns unevenly or abnormally in your cylinders, resulting in an awful knocking or pinging sound. The knock sensor detects knock and warns you if there’s an issue.
This will involve accessing, but not removing, the knock sensor. In some vehicles this is easy, and in others it’s an arduous process. You’ll need a repair manual for your specific make, model, and year of vehicle and refer to it to find where to locate the knock sensor.
Once you’ve access to the knock sensor, you’ll use a multimeter to test continuity by connecting the positive end to the knock sensor and the negative end to a ground point. You should be seeing a number greater than 10 ohms. If you’re not, it’s a strong indicator the knock filter isn’t working correctly and should be replaced.
The price of a replacement knock sensor can vary wildly from one car to the next. Some will only cost $30 or $40, while others could cost hundreds of dollars. On average, you’re looking at spending around $75 to $150.
Replacing your own knock sensor can certainly save you some money by cutting out labor costs. But if you want to save big bucks—we’re talking hundreds of dollars per year—it’s your
car insurance
that really needs replacing.
The
Jerry
app is already saving millions of drivers an average of over $800 per year on car insurance. You just install the app and answer a few questions, and this
super app
will show you quotes in as little as 45 seconds!
View full answer 
WHY YOU CAN TRUST JERRY
Jerry partners with more than 50 insurance companies, but our content is independently researched, written, and fact-checked by our team of editors and agents. We aren’t paid for reviews or other content.

Join 4M+ members in lowering their car insurance

Easiest way to compare and buy car insurance

√
No long forms
√
No spam or unwanted phone calls
√
Quotes from top insurance companies
Find insurance savings