What Happened?????
 

I have an odd problem. I’m wondering if anyone may have an idea as to what happened.
My daughter started her 2013 Mazda2 this morning at 7:00am to let it warm up. It was a cold 8 degrees Fahrenheit this morning.
According to my her, the car started just fine. She then went into the house while the car idled for 30 minutes with the heater and headlights on.
When she went back outside, she heard the car engine die. When she tried to start it back up, all it would do is click.

That’s when she called me. From what she is describing, it sounds like the battery died. I got home at noon to check it out.
When I got home the temp outside was 25 degrees. I checked the battery with my volt meter and read 12.8 V.
I turned the key and the car started right up. I then check the battery while running and read 14.6 volts making me think the battery and alternator are just fine.
The battery is the original and shows no sign of corrosion. The check engine light was off. I hooked up my Actron OBDII code reader to see if I could find any engine codes. Odd thing my tester seems to not work on this car.

So now I’m trying to figure out what went wrong. Any ideas anyone?
Will this car automatically turn off after idling for 30 minutes?
Should an OBDII tester work on this car?

UPDATE > I tried the scanner again and this time it worked.
No engine codes were present. Still trying to figure this out.

Any ideas anyone?

Only thing I can think of is your daughter didn't want to go to school that day lol. I'm just playing. I've never heard of this before. At first I was thinking a remote start but you said she went out to put things on. I'm curious now. I'm going to keep my eye on this one.