Circuit Description

ECM continuously monitors the response rates by measuring the switch time of HO2S output from lean to rich and vice versa during the closed-loop control. After the closed -loop control has started and the engine conditions have been met, every switch time (time differential value) are monitored for the side from lean to rich (rising of waveform) and the side from rich to lean (falling of waveform). Additionally, each sum of square (auto-correlation index) id calculated to average a predetermined cycle.

The response rate is calculated from the rise and fall of these values (auto-correlation index). If the resulting code is not responsive to HO2S1, the code data is stored in memory.