Yeah, their wording is strange, it leaves a grey area gap in time. I actually have a cheap OBDII tester, but the battery has been disconnected multiple times as it sat for 5 years, but I'd still go out and start it every month, just to make sure everything still worked. I've since drained, flushed, and refilled the coolant, oil, and brake fluid. I don't have any codes coming up currently, but the computer hasn't had any mileage to test anything either, just driveway idle time.