You can hack the temp probe to keep it from happening, but then the on-screen temp in incorrect.
It is claimed it is needed to meet federal defrosting standards, blah, blah,,,
But the heater element it the same as the Spark EV.
And worse,, it never warmed the engine all the way up. It just cycles the engine on and off just enough to provide ~153* coolant. It was a gas burning water heater.
But it was a great Road Trip car. So take that Sparkers...
Used '14 2LT w/ DCFC. +76 K miles.
Mostly free charging! Only one LONG visit to the shop....
GM needs Modern Troubleshooting tools for Modern EV's.
3 step Trouble Tree, 2nd guess not covered by warranty and cost $800. 3rd guess fixed the problem.