Patent ID: 7556016
Filing Date: 2009-07-07
Classification: F02D

Abstract:
1. A method to operate an internal combustion engine, comprising: providing an intake tract that communicates with a combustion chamber of a cylinder of the internal combustion engine based upon a position of a gas intake valve; providing a final control element in the intake tract to specify a mass air flow up to the combustion chamber; providing an injection valve for metering a fuel allocated to the cylinder; determining a value of an operating variable of the internal combustion engine based upon a first measured quantity of the internal combustion engine; determining if the value of the operating variable is reasonable depending on a second measured quantity of the internal combustion engine; determining if the internal combustion engine is operated in a lean operation when the value of the operating variable is not reasonable; changing the operation of the internal combustion engine to a quasi-stoichiometric operation of the internal combustion engine when the internal combustion engine is operated in lean operation and when the value of the operating variable is not reasonable; redetermining the value of the operating variable of the internal combustion engine based upon the first measured quantity of the internal combustion engine and determining if the redetermined value of the operating variable is reasonable depending on a remeasured second measured quantity of the internal combustion engine in response to the changeover to the quasi-stoichiometric operation; and changing the operation to the lean operation if the newly determined value of the operating variable is reasonable.