Knock Sensor 2 Circuit Range/Performance (Bank 2)

Possible causes

• CommonFailed knock sensor
• CommonSensor loose, or tightened to the wrong torque - these only work when clamped correctly to the block
• CommonCorroded connector or damaged wiring
• PossibleGenuine engine noise the sensor is correctly hearing - worn bearings, a loose component, or detonation from poor fuel
• PossibleWiring routed against the engine, picking up interference
• RareFailed control module input

What you might notice

• Noticeably less power, especially under load or up hills
• Worse fuel economy
• Pinging or knocking under acceleration
• Check engine light on
• Often no symptom beyond the light

What to check, in order

1. Listen to the engine yourself under load. A genuine knock or a mechanical rattle means the sensor is doing its job and the noise is the fault.
2. Understand what has been lost. The module listens for knock and retards ignition timing when it hears it; without a trustworthy sensor it retards timing as a precaution, which is why the car feels flat rather than sounding wrong.
3. Check the sensor is tight and correctly torqued. These sensors read vibration through their mounting, so a loose one or one tightened wrongly reports nonsense while looking perfect.
4. Inspect the connector and wiring - the harness runs across a hot engine.
5. Try a tank of the fuel grade the manufacturer specifies. Genuine detonation from low-octane fuel makes a working sensor report knock, and that is not a fault.
6. Find out where the sensor is before committing. On many V engines it sits under the intake manifold, and the labour costs far more than the part.