Inventors:
Richard Radu - Grand Blanc MI,
Robert Nankee - Canton MI,
William Eichbrecht - Livonia MI,
Leon Cribbins - Farmington MI,
Joseph Kopera - Trenton MI,
George Mitchell - Brighton MI,
International Classification:
G01N027/00
Abstract:
A method of filtering an oxygen sensor signal is provided. The method includes obtaining the oxygen sensor signal from the oxygen sensor on a periodic basis. The oxygen sensor signal is then compared to an average oxygen sensor signal value. If the oxygen sensor signal is greater than the average oxygen sensor signal value, a high signal counter is incremented. If the high signal counter is greater than a high signal count threshold, the oxygen sensor signal is forced to a high signal value. If the oxygen sensor signal is less than the average oxygen sensor signal value, a low signal counter is incremented. If the low signal counter is greater than a low signal count threshold, the oxygen sensor signal is forced to the low signal value. The high and low signal count thresholds correspond to a preselected period of time indicating a low or high signal trend within the oxygen sensor signal.