After battery replacement at dealership, total mileage odometer went up about 4000 miles, from about 16500 to 20600. Before battery replacement, car electronics were clearly erratic during attempts to start with weak battery.
A weak battery could have caused the odometer to give a false reading. On some vehicles the mileage is stored in both the instrument cluster and the Body Control Module and a fresh battery will allow the two to sync up. Your Honda may have had the same issue. That’s my best guess, anyway.
Your answer was better than a good guess!
I believe you are right. The effect on the odometer of the weak battery was opposite of what I thought. The odometer reading was temporarily reduced by 4000 miles until the new battery was installed. I was able to confirm this after looking at my last previous oil change service record which indicated mileage higher than what was displayed with the weak battery. It’s all good and I’m slightly embarrassed for jumping to the wrong conclusion. Thanks so much.
We all get an opportunity to learn. I would not have guessed that.
I’ve heard of it happening with some old Saturns so I took a guess. Who knew?