what does this symbol mean?
SAE J2012 A scan tool screen showing the code P0327

P0327: Knock sensor 1 circuit low input

An OBD-II trouble code meaning knock sensor 1 is sending a signal lower than the engine computer expects.

How to read it

P0327 is one of the standard OBD-II trouble codes stored when the check engine light comes on. Volkswagen’s service information names it “Knock Sensor 1 Circuit Low Input”, and a Kia service bulletin gives the same name.

Also searched as: code P0327, P0327 code.

Code names follow SAE J2012. Manufacturers add codes of their own, and the same code can have several causes: the vehicle’s service information or a qualified mechanic can say what it means for a particular car.

What the monitor checks

The federal rule’s catch-all covers any other electronic powertrain component that sends input to or takes commands from the on-board computer and has a measurable effect on emissions.

Look-alikes

Kia’s bulletin names it alongside P0326, “Knock Sensor 1 Circuit Range/performance”, the range/performance code for the same sensor.

What the manual says to do

Ford’s F-150 manual says that if the indicator stays on, the vehicle should be serviced at the first available opportunity, and that continued driving with it on can mean higher emissions, lower fuel economy, rougher running and more costly repairs.

How the light goes out

Under the federal rule, the check engine light may go out once the fault has not come back during three trips in a row in which its monitor runs without finding it. The system may erase the stored code if the same code has not been registered again in at least 40 engine warm-up cycles.

More OBD-II trouble codes

The same shape elsewhere

Sources

Researched, edited and approved by Rory Hansen before publishing. Last reviewed October 9, 2026. How we research

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