I changed the oil less than three months ago, and the monitor is already telling me to change it again. I've driven just over 200 miles in those 3 months. I've only owned the truck for 6 months, and the oil had just been changed when I bought it. The monitor was on early for the previous batch too, but I attributed that to a faulty temp sensor making the ECM think that the truck had overheated. The new temp sensor fixed all the overheating false alarms, but still the oil life monitor activated too early.

Are there any sensors that can cause the ECM to speed up the countdown?

Gozer
2005 GMC Yukon XL Denali 6.0L