P0325 Knock Sensor 1 Circuit (Bank 1 or Single Sensor)

Common causes

• Failed knock sensor
• Damaged wiring or connector (often buried under the intake manifold)
• Corroded connector

Symptoms

• Check engine light
• Slightly less power and fuel economy, because the computer retards spark timing to play it safe

Can I drive with it?

Usually safe to drive – the computer protects the engine by backing off the timing. Use the fuel grade your owner's manual recommends.

Tip: On many V6 and V8 engines the knock sensors sit under the intake manifold, so a 'cheap' sensor can mean several hours of labor – get a quote first.

Which scanner reads it?

Any OBD2 scanner reads it.

Budget tools like the ANCEL AD310 read it; tools with live data and graphing – like the BlueDriver or OBDLink MX+ – help you find the cause. Not sure which fits you? Try the Find My Scanner quiz.

In the data

How common is it? At New York’s emissions inspections in 2020–21, P0325 was the #19 code found on cars that failed – 1.0% of all the codes found.

Of the vehicle complaints owners filed with NHTSA from 2015 to 2025, 10 quote P0325 – most often from Chevrolet, Ford, GMC owners. Complaints lean toward serious problems, so treat this as a sign of how often the code turns up in real reports, not how often cars get it.

Both sources are compared on the Trends page.

Related codes

• P1326 Knock Sensor Detection System (Hyundai/Kia)
• P0300 Random/Multiple Cylinder Misfire Detected
• P0008 Engine Position System Performance (Bank 1)
• P0010 'A' Camshaft Position Actuator Circuit (Bank 1)
• P0011 'A' Camshaft Position – Timing Over-Advanced or System Performance (Bank 1)
• P0014 'B' Camshaft Position – Timing Over-Advanced or System Performance (Bank 1)

General information to help you understand a code – not a diagnosis. Your car’s service information or a qualified mechanic has the final word. See how we research.