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P0325

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

Moderate severity

This code means your car's computer isn't getting a proper signal from the knock sensor, which is designed to detect engine knocking or pinging. This sensor helps the engine adjust timing to prevent damage.

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

Common causes

  • Faulty Knock Sensor

    The sensor itself can fail internally, leading to an incorrect or absent signal.

    high

    Typical part cost: $50-200 part

  • Wiring Harness Issues (open, short, corrosion)

    Damaged wires or corroded connectors between the sensor and the PCM can disrupt the signal.

    medium

    Typical part cost: $0-150 for repair

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First things to check

  1. 1Inspect the knock sensor wiring and connector for damage, corrosion, or loose connections.
  2. 2Test the knock sensor resistance and voltage output according to manufacturer specifications.

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Tools you may need

Already have a compatible scanner? Use it. If not, a Bluetooth OBD2 adapter can help you confirm engine codes and check supported live sensor data before replacing parts.

Illustration of a Bluetooth OBD2 adapter, not a product photo

Basic checks

Veepeak OBDCheck BLE

A Bluetooth LE adapter for reading standard engine codes and supported live data.

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Illustration of a Bluetooth OBD2 adapter, not a product photo

Regular diagnostics

vgate iCar Pro BLE 4.0

A Bluetooth LE adapter with an automatic sleep feature for routine code and sensor checks.

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Illustration of a Bluetooth OBD2 adapter, not a product photo

Another option

OBDLink CX

A Bluetooth LE adapter to consider when comparing supported vehicles and diagnostic apps.

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Illustrations shown, not product photos. Check vehicle, phone and app compatibility before buying. These adapters do not guarantee access to ABS, airbags or manufacturer-specific systems. Clearing a code does not repair the fault and can reset emissions readiness monitors.

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Related codes

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Frequently asked questions

What does a knock sensor do?

A knock sensor detects vibrations caused by engine knocking or pinging, which is premature ignition of the air-fuel mixture. It sends a signal to the engine computer, which then adjusts ignition timing to prevent damage.

Can a bad knock sensor cause engine damage?

Yes, if the knock sensor isn't working, the engine computer can't detect and correct knocking, which can lead to pre-ignition or detonation, potentially causing serious internal engine damage over time.

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