Patent ID: 11965472
Assignee: FORD GLOBAL TECHNOLOGIES, LLC
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F | IPC F

Claim 9:
10. A vehicle, comprising:
an internal combustion engine including a plurality of cylinders with at least a first and second cylinder of the plurality of cylinders associated with a sensor configured to provide a signal used in determining air-fuel ratio of the first and second cylinders; and
a vehicle controller programmed to:
monitor air-fuel ratio of cylinders previously identified as having air-fuel ratio determinations that satisfy predetermined criteria for current engine operating conditions, the previously identified cylinders including only one of the first and second cylinders for at least one engine operating condition;
repeat the monitoring of the air-fuel ratio as engine operating conditions change until each of the plurality of cylinders has a predetermined number of air-fuel ratio determinations; and
generate a diagnostic signal in response to an air-fuel ratio variation among the plurality of cylinders exceeding an associated threshold, wherein the associated threshold corresponds to at least one of: a rate of false-positives, and a rate of false-negatives.