P0327: Knock Sensor 1 Circuit Low Input (Bank 1)

written by Edmunds.com^{This story was created with generative AI and was reviewed and fact-checked by our staff of editors and experts.}
edited by Nick Yekikian^{Senior News Editor
Nick Yekikian has worked in the automotive industry since 2019. He has written close to a thousand car-related articles and tested and reviewed more than 200 vehicles over the course of his career. Nick is the Senior News Editor at Edmunds and has also contributed to MotorTrend, Automobile Magazine and Super Street. When Nick isn't zipping around town in his latest used-car find, he's probably making digital art in Photoshop or playing disc golf with friends.}
3/20/2025
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Understanding error code P0327

The P0327 diagnostic trouble code (DTC) stands for "Knock Sensor 1 Circuit Low Input (Bank 1)." This code is triggered when the engine control module detects an abnormally low voltage signal from the knock sensor on bank 1. The knock sensor monitors engine vibrations to detect combustion (knocking) and helps the engine control module adjust ignition timing for optimal performance.

Why you should address P0327

If the knock sensor fails to detect knocking properly, the engine control module won't make the necessary timing adjustments and that can lead to potential engine damage. Persistent knocking can result in excessive wear on pistons, bearings, sleeves and other internal components, increasing the risk of costly repairs. Poor ignition timing may also cause reduced fuel efficiency and acceleration.

Can I safely drive my car with this code?

While you can drive your car with this error code, it is not recommended. Without proper knock detection, the engine may operate under less-than-optimal conditions, increasing the risk of internal damage over time. If symptoms such as poor acceleration, rough idling, or engine knocking (a persistent loud sound that's more aggressive than normal ticking) are noticeable, it's best to address the issue as soon as possible to prevent further damage.

Symptoms of the P0327 error code

Illuminated check engine light
Reduced acceleration and sluggish response from the engine
Engine knocking or pinging noises
Decreased fuel efficiency
A rough idle

How is the P0327 error code diagnosed?

Diagnosing the P0327 code typically involves the following steps:

Scan for codes: Use an OBD-II scanner to confirm the presence of P0327 and check for related codes.
Inspect the knock sensor: Check for visible damage, loose connections or corrosion on the sensor.
Examine wiring and connectors: Look for broken, frayed or shorted wires that could cause a low signal.
Test the knock sensor: Use a multimeter to check the sensor’s resistance and compare it to manufacturer specifications.
Check the engine control module: If all other components are functional, test the engine control module for any faults in communication with the knock sensor.