On Board Diagnosis Logic
WARNING: This page is about a different car, the 2005 Nissan 350Z. However, it is still accessible from the selected car via links, so may be relevant.
To judge the malfunction of A/F sensor 1, this diagnosis measures response time of the A/F signal computed by ECM from the air fuel ration A/F sensor 1 signal. The time is compensated by engine operating (speed and load), fuel feedback control constant, and the A/F sensor 1 temperature index. Judgment is based on whether the compensated time (the A/F signal cycling time index) is inordinately long or not.