What causes my 2018 chevy volt check engine light to come on?

Check engine lights are general catch-alls that tell You that Your car is throwing one or more diagnostic trouble codes (DTCs), that need to be read with an OBD-II scan tool. There are dozens, if not a hundred or more, reasons that Your check engine would illuminate, in all vehicles including the 2018 Chevrolet Volt. Even though You won't often be using gas in Your Volt, a common cause can be an improperly seated or tightened gas cap. Low engine coolant is another common cause, perhaps caused by a low battery. But seriously, the causes and fixes range so drastically that without checking Your DTCs, there's no way to even give You an accurate ballpark; while some stuff is more common than other stuff, that's far from meaning it's what's happening to You.