"Check Hybrid System" & Radio/Nav

Over the weekend, I tried to replace the touch screen on my Radio/CD/Navigation unit (E7022) on my 2011 Prius. For reasons I won't go into here, I was unable to reconnect the screen's ribbon cable to the motherboard, so the screen remains deactivated. Because of that, when I reinstalled the radio unit, I didn't bother to reconnect the various cables (I never use the stereo, anyway).

This morning, I cranked the car for the first time since removing and replacing the unit. The status screen (or whatever you call it by the speedometer) now constantly displays "Check Hybrid System." I haven't had an opportunity to read the trouble codes, but could not re-attaching all the cables to the radio/navigation unit cause this?