Can a water pump go bad with no check engine light?

I "was" using a ScanGauge for this, till it started causing problems: kept getting brake/traction warning lights, "Check Hybrid System", and work-to-rule brakes. The latter kinda scary: at first it feels like NO brakes. Dealership mechanic suggested I stop having a constant OBD plug-in, and that did the trick.

Yeah, there are workarounds, but they can backfire. And it used to be the norm to have a coolant gauge, in the dash, from the factory.

I wouldn't wait for trouble, just replace them both, at least every 100k miles. Like an oil change. Changing the inverter water pump is a chore...