Correct.If you just reset the oil change tracker, it doesn't skip monitoring the other service items does it? So when you get to the next 15% it should still be accurate with the code... Am I understanding this correctly?
If you perpetually reset the oil life before it reaches 15%, the other maintenance codes will never display. However, once you let it reach 15%, other maintenance codes that are due or past due will be displayed. They're only cleared if the MM is reset while those other codes are displayed once the oil life reaches 15%.
The big problem occurs if you always change the oil before the MM indicates reaches 15% either because you never drive enough miles in a year or if you change the oil before prompted by the MM and reset the MM (i.e., dealer-recommend premature oil changes or old habits).