July 1: So it begins. Don't worry, this is not in the correct legal jurisdiction!
Code P1000: OBD-II Monitor System Error
WARNING: This page is about a different car, the 1995 Mazda B4000, 1995 Mazda B3000, and 1995 Mazda B2300. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Trouble Codes No. P1000 OBD-II Monitor System Error