Systems and methods for controlling knock in an internal combustion engine are presented. In one example, spark timing is retarded in engine cylinders where engine knock is indicated and spark is subsequently advanced after it has been retarded. The rate spark timing is advanced may be based on a way engine cylinders have been deactivated.

Systems and methods for detecting and controlling knock in an engine are presented. In one example, engine knock sensors are selected based on whether or not certain cylinders are activated and combusting air and fuel or deactivated and not combusting air and fuel. Output of selected knock sensors is the basis for adjusting engine spark timing.

Systems and methods for detecting and controlling knock in an engine are presented. In one example, engine knock sensors are selected based on whether or not certain cylinders are activated and combusting air and fuel or deactivated and not combusting air and fuel. Output of selected knock sensors is the basis for adjusting engine spark timing.

Systems and methods for operating an engine with deactivating and non-deactivating valves are presented. In one example, fuel supplied to cylinders being reactivated is supplied by direct fuel injectors even though the engine is operating in a region (e.g., speed and torque) where under conditions where cylinders are not being reactivated the engine injects fuel solely via port fuel injectors.

Systems and methods for operating an engine with deactivating valves are presented. In one example, deactivated valves may be reactivated to increase a rate of camshaft phase indexing relative to engine crankshaft position. However, if a desired rate of camshaft indexing is low, the engine cylinders may remain deactivated based on the low rate of desired camshaft indexing.

Systems and methods for operating an engine with deactivating valves are presented. In one example, deactivated valves may be reactivated to increase a rate of camshaft phase indexing relative to engine crankshaft position. However, if a desired rate of camshaft indexing is low, the engine cylinders may remain deactivated based on the low rate of desired camshaft indexing.

Systems and methods for operating an engine with deactivating and non-deactivating valves are presented. In one example, an actual total number of deactivated cylinders may be adjusted to control driveline braking. The driveline braking may be controlled in a towing mode, a hill descent mode, and during normal driving conditions.

Systems and methods for operating an engine with deactivating and non-deactivating valves are presented. In one example, engine volumetric efficiency actuators are adjusted in response to a request to activate engine cylinders so that engine intake manifold pressure is drawn down quickly toward its normal state at the engine's present speed and torque.

Systems and methods for operating an engine with deactivating and non-deactivating valves are presented. In one example, engine volumetric efficiency actuators are adjusted in response to a request to activate engine cylinders so that engine intake manifold pressure is drawn down quickly toward its normal state at the engine's present speed and torque.

Systems and methods for operating an engine with deactivating and non-deactivating valves are presented. In one example, a position of an engine air intake throttle is adjusted during cylinder deactivation to control intake manifold pressure for cylinder reactivation. Closing of the throttle may be timed based on an actual total number of cylinder induction events expected to provide a desired engine intake manifold pressure.