Abstract: An engine control system for monitoring torque increase during cylinder deactivation for a displacement on demand (DOD) engine includes a throttle and a controller. The controller adjusts a preload of the throttle prior to a cylinder deactivation event and determines whether a DOD fault is present during the cylinder deactivation event. The controller one of operates the engine without the preload in the deactivated mode and switches the engine back to the activated mode if the fault is present for a predetermined time. The controller cancels the preload if the DOD fault is present and resets the preload if the predetermined period has not expired. The DOD fault includes one of an engine speed fault, a transmission gear fault and a fueled cylinder fault.

Abstract: An engine toque estimator according to the invention includes a vehicle data bus that provides a plurality of engine operating inputs including at least one of engine RPM, spark and a dilution estimate. A steady state torque estimator communicates with the vehicle data bus and generates a steady state engine torque signal. A measurement model communicates with the vehicle data bus and compensates for errors associated with engine-to-engine variation. A dynamic torque estimator communicates with at least one of the vehicle data bus, the measurement model, and the steady state torque estimator and generates an actual torque signal.