Cylinder 3 sits in the middle or front of the engine block. The knock sensor monitors cylinder 3 during its combustion cycle. If it detects knocking, it delays ignition timing. If the knocking persists, it sets this code. A clogged fuel injector or a worn spark plug on cylinder 3 are typical causes.
Mechanic Glossary
3 Above Knock Threshold
A diagnostic code indicating that combustion knocking in cylinder 3 exceeds safe parameters.
Frequently Asked Questions
The engine computer detected pre-ignition knocking in cylinder 3 that was louder than safe limits.
A lean air-fuel ratio in cylinder 3, a bad spark plug, or low-octane fuel. Carbon deposits on the piston can also cause pre-ignition.
Inspect the spark plug, clean the fuel injectors, or use a higher octane fuel to prevent knocking.