×

Apparatus for detecting abnormality of oxygen sensor and controlling air/fuel ratio

  • US 5,020,499 A
  • Filed: 06/18/1990
  • Issued: 06/04/1991
  • Est. Priority Date: 06/16/1989
  • Status: Expired due to Term
First Claim
Patent Images

1. An apparatus for regulating the emission of exhaust gas discharged from an internal combustion engine, comprising:

  • oxygen sensing means for generating an oxygen concentration signal indicating the concentration of exhaust gas discharged from an internal combustion engine;

    air/fuel ratio setting means for setting the air/fuel ratio of air to fuel in an air/fuel mixture supplied to the internal combustion engine based on a predetermined threshold value and the value of the oxygen concentration signal during closed loop control and for selectively setting the air/fuel ratio to either rich or lean during open loop control; and

    abnormality detection means operable during open loop and closed loop control for determining that the oxygen sensing means is abnormal when the oxygen concentration signal is outside of a predetermined range.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×