Diagnostic Method

Calculate faf difference and the λ value difference every 32ms x 4. Calculate the diagnosis value after calculating 1640 time.

• Abnormality Judgment 

  If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.

  Judgment Value 

  JUDGMENT VALUE
  
  

  Malfunction Criteria	Threshold Value
  parafca = td2faf/td2lmd	> 0.644 (AT model) > 0.444 (MT model)
  where, td2faf (N) = td2faf (n-1) + |d2faf (n)| td2lmd (N) = td2lmd (n-1) + |d2lmd (n)| add up to 32 ms x 4 x 1640 time. d2faf (n) = (faf (n) - faf (n-1)) - (faf (n-1) - faf (n-2)) d2lmd (n) = (lmd (n) - lmd (n-1)) - (lmd (n-1) - lmd (n-2)) faf = main feedback compensation coefficient every 128 milliseconds lmd = output lambda every 128 milliseconds

  Time Needed for Diagnosis:  32 ms x 4 x 1640 time

  Malfunction Indicator Light Illumination:  Illuminates when malfunction occurs in 2 continuous driving cycles.

• Normality Judgment 

Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time.

Judgment Value 

Time Needed for Diagnosis:  32 ms x 4 x 1640 time