V12 engines monitor twelve separate cylinders for knock. Cylinder 11 is situated near the back of the engine block on the driver's side (on standard bank configurations). When detonation occurs in this cylinder, the knock sensor registers a vibration peak. The computer registers this code and delays spark timing for cylinder 11 to stop the knock. Fuel delivery issues or cylinder-specific air leaks are common causes.
Mechanic Glossary
11 Above Knock Threshold
A fault indicating that combustion vibrations in cylinder 11 of a V12 engine exceed safe limits.
Frequently Asked Questions
A weak fuel injector on that cylinder, carbon buildup, or an intake manifold vacuum leak near cylinder 11.
Drive conservatively. Avoid heavy throttle to prevent piston and valve damage in that cylinder.
Check the cylinder 11 spark plug for signs of lean running (white deposits). Swap the fuel injector with another cylinder to see if the code moves.