My 2009 Rio 5 will blow cold on some vents and hot on other vents. Help!

Does your Rio have dual zone climate control? I don't think it does -- two dials -- one for each the driver and passenger side? Each dial controls the temperature for each side separately. I think this is a basic vehicle and not so equipped. If you are experiencing hot on the driver's side and cold on the passenger side, it could be that you have a low charge to your air conditioning system. Other than that, it'll require some hands on troubleshooting to figure out what is going on. Good luck.