Abstract:
Methods are provided for accurately learning part-to-part variability of an intake or exhaust oxygen sensor. A correction factor is learned based on a sensor reading in dry air conditions, the dry air reading learned by applying a higher reference voltage to the sensor. An ethanol transfer function is then adjusted based on the learned correction factor so as to improve the accuracy of combusted fuel ethanol content estimation.
Abstract:
Methods and systems are provided for determining an amount of alcohol in fuel injected into an engine based on outputs from an exhaust gas sensor. In one example, a method includes estimating a first fuel alcohol content based on an air-fuel ratio estimated with the exhaust oxygen sensor and estimating a second fuel alcohol content based on a change in sensor output during modulating a reference voltage of the exhaust oxygen sensor between a first and second voltage. The method further includes adjusting engine operation based on a difference between the first and second fuel alcohol contents.
Abstract:
Various systems and methods are described for an engine system with an exhaust gas recirculation system. In one example method, a correction for a gas constituent sensor is determined based on output from the gas constituent sensor and output from a pressure sensor over a range of boost pressure. The gas constituent sensor output is adjusted based on the correction, and an amount of exhaust gas recirculation is adjusted based on the adjusted gas constituent sensor output.
Abstract:
Methods are provided for accurately learning part-to-part variability of an intake or exhaust oxygen sensor. A correction factor is learned based on a sensor reading in dry air conditions, the dry air reading learned by applying a higher reference voltage to the sensor. An ethanol transfer function is then adjusted based on the learned correction factor so as to improve the accuracy of combusted fuel ethanol content estimation.
Abstract:
Methods and systems are provided for determining an amount of alcohol in fuel injected into an engine based on outputs from an exhaust gas sensor. In one example, a method includes estimating a first fuel alcohol content based on an air-fuel ratio estimated with the exhaust oxygen sensor and estimating a second fuel alcohol content based on a change in sensor output during modulating a reference voltage of the exhaust oxygen sensor between a first and second voltage. The method further includes adjusting engine operation based on a difference between the first and second fuel alcohol contents.
Abstract:
Various systems and methods are described for an engine system with an exhaust gas recirculation system. In one example method, a correction for a gas constituent sensor is determined based on output from the gas constituent sensor and output from a pressure sensor over a range of boost pressure. The gas constituent sensor output is adjusted based on the correction, and an amount of exhaust gas recirculation is adjusted based on the adjusted gas constituent sensor output.