Patent ID: 7025035

Claim:
A method for controlling a multi-displacement system for an internal combustion engine, wherein the multi-displacement system includes a solenoid in hydraulic communication with a hydraulically-deactivatable valve train component, the solenoid being triggered using an event-based timer correlated with changes in a crankshaft position as detected by a crankshaft sensor, the method comprising: when operating the engine in a full-displacement mode at a first engine speed and a first engine oil temperature, retrieving a first value from a plurality of calibratable values representative of a time-based hydraulic deactivation delay based on the first engine speed and the first oil temperature; determining a first time period between current changes in crankshaft position; dividing the first value by the first time period to obtain an event-based hydraulic deactivation delay; and triggering the solenoid to move from a closed position to an open position based on the hydraulic deactivation delay.