Patent ID: 7169080

Claim:
A control system for an internal combustion engine having a plurality of cylinders and switching means for switching between an all-cylinder operation in which all of said plurality of cylinders are operated and a partial-cylinder operation in which at least one of said plurality of cylinders is halted, said control system comprising: operating parameter detecting means for detecting operating parameters of a vehicle driven by said engine, said operating parameters including at least one operating parameter of said engine; condition determining means for determining a condition for performing the partial-cylinder operation, based on the operating parameters detected by said operating parameter detecting means; modifying means for modifying a result of the determination by said condition determining means so that the partial-cylinder operation may be continued, when the detected operating parameters satisfy a predetermined continuation condition within a predetermined time period from the time a vehicle operating state where the condition for performing the partial-cylinder operation is satisfied, has changed to another vehicle operating state where the condition for performing the partial-cylinder operation is not satisfied; and instructing means for instructing said switching means to perform the partial-cylinder operation or the all-cylinder operation according to the result of the determination modified by said modifying means.