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P0325

Knock Sensor 1 Circuit Malfunction Bank 1

Diagnose P0325 knock sensor code. Learn what the knock sensor does and how to test and replace it.

Sensors & Electronics

Symptoms

  • 1Check engine light on
  • 2Reduced power or sluggish acceleration
  • 3Engine ping or knock under load
  • 4Slightly reduced fuel economy
  • 5Higher engine temperatures in some cases

Common Causes

  • 1Failed knock sensor
  • 2Damaged wiring or connector
  • 3Loose sensor mounting bolt
  • 4Corrosion at the connector
  • 5ECM fault (rare)

How to Fix

  • 1Inspect wiring and connector for damage
  • 2Verify the sensor is torqued to spec
  • 3Test knock sensor resistance
  • 4Repair corroded or damaged wiring
  • 5Replace the knock sensor if faulty

What Does P0325 Mean?

The P0325 code indicates a fault in the knock sensor circuit on Bank 1. The knock sensor detects engine detonation (pinging) so the ECM can retard ignition timing to protect the engine.

Why It Matters

Without a working knock sensor, the ECM may pull timing as a precaution, reducing power and fuel economy, or fail to protect the engine from damaging detonation.

Common Causes

Failed sensors, damaged wiring, and loose mounting are typical. On many engines the knock sensor sits under the intake manifold, making access labor-intensive.

Using AI4Car

AI4Car can read knock sensor activity and ignition timing corrections to help confirm whether the sensor circuit is functioning.
P0326P0327P0328P0330

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