some fancier ones had battery protection, if it got to low it would start.
others had temp sensors and would start once in a while when it got really cold.
likely one of those two options setup in it.
Yup, that sounds like what it was. It woild come on at like -20 or so (the house woild be snapping znd creaking from the cold, waking me up, then the engine starts up- first time it happened I didn’t know what was going on lol)