2005 Prius Climate Control Issue

Clock spring behind steer wheel . And if you can bring up your MFD the center screen if you put the system on l o fan on medium the yellow button on over the air conditioning does the air conditioning work and cold air come out and then what happens if you go from that and you push the front defrost button does cold air defrost it there come out up to the windshield? You got to get your MFD straightened out and you may have a problem with your clock spring If your MFD is not working correctly that's probably where I would start they're cheap enough now You can buy these things from a junkyard for 25 bucks No they're not all broken out in the wild I find good ones everyday depending upon which model you have this is for the four button non-GPS but backup camera capable MFD actually pretty simple stuff.

 

Sounds like the clock spring behind the steering wheel may be suspect If you try to operate buttons that don't work when you normally try to push them on the steering wheel try and turn the steering wheel while pushing the given button does the device all of a sudden come on bingo there's a short in the clock spring wiring replace it and everything should be generally restored pretty simple relatively inexpensive The MFD could be tied to the CM monitor display issue which is your speedometer gas gauge and transmission display so generally when that's out your MFD may be out not sure I don't see your car from here.

 

There could be trouble codes from the HVAC system that would help pin down what is going on. The easiest way to get those is on the MFD (as described here), but if your MFD isn't working, a suitable scan tool would be the only way. Suitable means it has to be one that can talk to all the ECUs in a Prius, and then your HVAC codes will show up, generally as B14xy codes.

This thread talks about suitable scan tools: Gen2 OBD2 app review | PriusChat