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

Common causes

• A failed knock sensor
• Damaged wiring or a corroded connector (common on engines where the sensor sits under the intake)
• A loose sensor not torqued to spec

Code meanings can vary slightly by manufacturer. Use these as a starting point and confirm with your vehicle's service information or a mechanic before replacing parts.

Symptoms

• Check engine light
• Sometimes reduced power or fuel economy as the computer retards timing
• Pinging under load in some cases

Is it safe to drive?

Usually drivable, but avoid hard acceleration and heavy loads until it's fixed.

How to check it with a scanner

1. Plug an OBD2 scanner into the port under the dashboard and read all stored codes and the freeze-frame data (the conditions when the code set).
2. Inspect the knock sensor connector and wiring.
3. Check the sensor's resistance or output against your vehicle's spec.
4. On many V engines the sensor is under the intake manifold, so check the repair time before starting.
5. After a repair, clear the code and drive normally for a few days to confirm it doesn't come back.

A basic code reader shows the code; scanners with live data let you watch sensor readings, which is what you need for most of the checks above. See OBD2 scanners under $100.

Questions

Related codes

• P0300: Random or multiple cylinder misfire
• P0011: Intake cam timing over-advanced, bank 1
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