摘要 |
When carrying out abnormality determination for an air-fuel ratio sensor 33 by comparison of an average value tave of all diagnostic values t(n) and an abnormality determination value C, the abnormality determination value C is corrected using an average value Deltatave for the disturbance correction values Deltat(n). A disturbance correction value Deltat(n) is derived by subtracting a correction reference value A, which is a diagnostic value with a normal air-fuel ratio sensor 33 when there is no disturbance, from the diagnostic value t(n). The present invention provides the abnormality diagnosis device for the air-fuel ratio sensor that can acquire highly precise diagnosis results without lowering frequency of diagnosis accurately taking into consideration the influence of disturbance.
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