METHODS AND SYSTEMS FOR FUEL ETHANOL CONTENT DETERMINATION VIA AN OXYGEN SENSOR

摘要

Methods are provided for accurately learning part-to-part variability of an intake or exhaust oxygen sensor. A correction factor is learned based on sensor readings at voltages above and below a voltage corresponding to dry air conditions. 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.

主权项

1. A method for an engine, comprising:
during selected conditions, operating an oxygen sensor at a lower reference voltage where water molecules are not dissociated to generate a first output and at a higher reference voltage where water molecules are fully dissociated to generate a second output; and learning a correction factor for the sensor based on the first and second outputs.