eDommer, I'll assume you have ACC. Your problem is normal. My '17 Volt also disables the ACC in moderate or heavy rain. Guess why? The radar sensors that are "seeing" the car in front of you are being overwhelmed by water and the system shuts down to protect you. If it didn't, it may keep your set speed and hit the car. I'll bet those here with the "normal" CC do not see this shut down as the driver is used to manually keeping distance with cruise. (And really, nobody should be using cruise in those conditions anyway).I've have the same problem on my 2017 Volt. Seems to only occur after driving in very heavy rain. After I park the car in the garage for a couple of hours it's fine.