Well, despite the fact that the battery was replaced shortly before I bought the car, this now appears to almost certainly be an issue with the vehicle battery.

Yesterday I had to take the rear door panel off to repair the vapor barrier. The door was left open for extended periods multiple times throughout the day. Later in the evening, we got in the car to run some errands and as the motor first started a warning flashed across the check control about additional charging load. Then I noticed the mpg and trip meter were reset.

My wife then informed me that the last time it happened to her, it was when she spent a while with the door open switching out child seats.

I'll have to confirm with some voltage checks, but it seems the battery is weak, or perhaps the wrong model.

__________________