Knock Control

Knock sensors on the block listen for the vibration caused by knock. It allows engines to run with efficient timing on normal fuel. It can adjust timing for each cylinder individually. Live data often shows knock retard for each cylinder.

When knock is detected, the control unit fires the spark slightly later, then gradually advances it again.

Fuel with too low an octane rating causes power loss as timing is retarded. Faulty sensors or wiring make the system retard timing and reduce power.