CEL on, then off. Then on.

So my ‘15 sportwagen check engine light came on a few days ago at jistbover 21k miles. Stayed on two days, then went off. I already had an appointment scheduled so I took it in this morning. Light was back on. They diagnosed it as needing one of the three water pumps replaced. It’s covered under warranty, but they said it’s okay to drive until they get the part in since it just gets me “a little extra heat in the cabin”. Any opinions on the accuracy of that, and is that something that would trip the engine light? I thought engine light pertains to emissions, which seems completely different from cooling.
Car is runnng great.

The CEL will come on for any engine malfunction. The pump in question is, most likely, the "Heater Support Pump" (V488) and it does not effect engine cooling. Drive more, worry less.

Here's a LINK to the study guide for the EA288 engine. Everything you need to know is in there.

The cooling system is absolutely part of the emissions compliance, as the engine must be able to get to operating temp. Therefor, the coolant temp and whatever components are necessary to regulate it, are indeed monitored and can be cause for an MIL request.

Variable displacement water pumps, active (electronic) thermostats, active grill shutters, transmission fluid temp regulators, etc. are all part of modern automobiles.

Thanks for the help. Should have the part in and installed early next week.