OBD-II Mode 01 PID 0 gives commanded MIL on (bit A7, see link) and Number of confirmed emissions-related DTCs (bit A6-A0, see link).
I did hit Mode 01 PID 01 on a few cars but got surprising results. In Skoda Superb, there was no visible Check Engine Light (or MIL) on, there was no commanded MIL ON (bit A7), but DTC count (bit A6-A0) was 16. How is it possible? If the commanded MIL is not ON, how can number of DTC count be non-zero?
Going through this website, MIL NOT Commanded ON & codes ARE stored = 0% cases. But the case in question is actually this case.
Side question: MIL Commanded ON & codes are NOT stored. Is this case possible? If yes, when can this case happen?