Gm Global Technolgoy Operations, Inc.

Thomas J Majcher

Stephen Paul Levijoki

John W Siekkinen

Scott R Jeffrey

Andrew Paul Bagnasco

Michael John Dokter

A system according to the principles of the present disclosure includes an error count module and a sensor diagnostic module. The error count module increases an error count when an actual air/fuel ratio is different from a desired air/fuel ratio and selectively adjusts the error count based on an actual engine speed. An oxygen sensor generates a signal indicating the actual air/fuel ratio. The sensor diagnostic module diagnoses a fault in the oxygen sensor when the error count is greater than a first predetermined count.

System and method for diagnosing a fault in an oxygen sensor based on engine speed

A system according to the principles of the present disclosure includes an error period module and a sensor diagnostic module. The error period module determines an error period based on an amount of time that a first air/fuel ratio and a desired air/fuel ratio are different. A first oxygen sensor generates a first signal indicating the first air/fuel ratio. The sensor diagnostic module diagnoses a fault in the first oxygen sensor when the error period is greater than a predetermined period.

System and method for diagnosing faults in an oxygen sensor

A system includes an offset determination module and a correction determination module. The offset determination module determines an offset value based on an average response time of an exhaust gas oxygen (EGO) sensor located upstream of a catalyst in an exhaust system. The offset value relates one of a predetermined number of cylinder imbalance values to a cylinder of an engine. The correction determination module determines a fueling correction for the cylinder based on the offset value and one of the predetermined number of cylinder imbalance values.

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Orchard Lake, MI, United States of America

Thomas J Majcher