I vote Gremlins... I use trip B for my oil changes.. I think mine reset once in 5+ years

 

Never had that happen with my 2017 in the 57k miles I've owned it, one trip meter I use for logging road trip distance and fuel economy, the other hasn't been reset since it left the factory and provides the lifetime average fuel economy. Perhaps the hubby did it by mistake since it happened in his truck as well? Or maybe the dealer or some other shop did it by mistake? Who knows.

Sometimes weird resets happen, though I've mainly heard of that happening with the engine hours on GM trucks, not the trip meters.

 

I do know that the oil reminder on my wife's Nissan zeroed out, even though the guy at Batteries Plus had plugged in the backup power supply before he pulled the battery.

I have always used Trip B to track miles since last oil change.

 

Huh. Ya, musta been gremlins.
P.S. We would have both done the same thing. He doesn't drive my truck or do my oil changes; I do. (I sometimes drive his when he's too tired from playing at camp and we still have a 1 1/2 hour drive home. )

 

Same thing happened to me a few weeks ago. Had never reset trip B myself then one day I noticed it was back down to around 100mi. Funny thing is the MPG didn’t reset and still has the same average that is my lifetime average. This was around 64k miles so I wonder if the trip meters will “roll over” after a certain mileage. OP, how many miles when yours mysteriously reset? Also FWIW, I have disconnected my battery before and didn’t have anything reset.

 

My trip B reset as well.

Just went and looked. Mine switched at 62136mi., which puts it somewhere between 11-17-20 and 12-01-20, between fillups. I know I didn't reset it, because I never look at that screen on the DIC between fillups. Thought it happened at the dealer during oil change, but I just looked at the service work order and it happened 130 mi before I took it in.

I ordered my 2016 new and I was going to keep trip B keeping track of miles to the decimal and fuel mileage since new. Needless to say, it kind of pissed me off. Trip A was being used for between fillups.

 

Same thing eventually happened to me. I was not happy but, there is nothing I can do about it.

 

Exactly the same for me, low 60000's. I was letting B keep running and resetting A at fuel fill-ups. I wasn't happy about it either, but I can think of many worse things to go wrong.

 

So it would seem they reset sometime after 60k miles

 

Might have reset when vehicle/GM performed an "over the air" computer update. Just a guess.

 

15 and 16's don't do OTA updates, 17+ do.