Patent ID: 8577645
Filing Date: 2013-11-05
Classification: F02D,G01M

Abstract:
1. An air/fuel imbalance diagnostic system comprising: a filtering module that receives an oxygen signal from an oxygen sensor, that selectively samples the oxygen signal, and that generates imbalance data samples using: wherein the oxygen sensor measures oxygen in the exhaust from the cylinders of the cylinder bank; an imbalance determination module that determines one air/fuel imbalance (AFIM) value for the entire cylinder bank based on a variance of a plurality of the imbalance data samples; an imbalance diagnostic module that selectively indicates that an AFIM is present in the cylinder bank based on the AFIM value; and a cylinder identification module that, in response to the imbalance diagnostic module indicating that the AFIM is present in the cylinder bank, attributes the AFIM to one of the cylinders of the cylinder bank.