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.
What you may notice
Symptoms
- 01Check engine light on
- 02Reduced power or sluggish acceleration
- 03Engine ping or knock under load
- 04Slightly reduced fuel economy
- 05Higher engine temperatures in some cases
Where to look first
Common causes
- 01Failed knock sensor
- 02Damaged wiring or connector
- 03Loose sensor mounting bolt
- 04Corrosion at the connector
- 05ECM fault (rare)
Step by step
What to check and repair
- 01Inspect wiring and connector for damage
- 02Verify the sensor is torqued to spec
- 03Test knock sensor resistance
- 04Repair corroded or damaged wiring
- 05Replace 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.