Hello, I noticed today the MFD is taking a while to boot up. Black screen will show for a while and it doesn't want to pull any information of the engine or AC system. I'm wondering what's going on since everything has been fine up till now.
Replaced the radio? The CAN bus (the computer bus that lets the components talk to each other) needs to be terminated properly, if the radio is changed and the CAN bus is not terminated, it can cause those symptoms. The MFD is a small computer and can break, but that looks like a communication problem. Loose plugs, hacked up (or chewed up--mice?) wires, bad radio, bad A/C Amplifier (A/C ECU--A/C working?), or any other component that is connected to the bus (practically everything in the Prius) could be causing noise. Anything plugged into the ODBII port? Having problems with any other component(s)? Had the dash open? Getting any codes?
Oh, troubleshooting rule #1--what has changed? Any changes around the time the MFD started acting up? Get the 12v battery jumped? For that matter, have you tried rebooting the car (disconnect 12v battery neg cable for about 10 minutes).
If nothing else is amiss, I would open the dash and unplug/replug (is that a word?) the MFD cables (and the radio, too) several times--there may be some oxidation on the contacts and that may take care of it.