The computer screen on my 2009 Prius only worked from time to time, and it was winter, so I used it to turn on the heater before it quit working entirely. Now the screen is 100% dead, but the heater is set to full blast. It's Spring, so how can I turn off the heater (and the air conditioner)?
Try pressing the auto A/C button on the steering wheel, that usually shuts off the entire thing when you toggle it in my experience--you can also lower the temp with the buttons below when it warms up in the Summer. Obviously it would be best to fix the screen but until then that may just have to do. They're about $200 on ebay and pretty straight forward to install as I found out. Here is a tutorial when you're ready:
Take caution removing and/or inserting those cable connectors! Some of the solder joints that get cracked internally are because some one was a bit too rough with the connectors. Do NOT bend them side to side with the cables attached. etc. etc. Be careful of ESD discharge when handling the display unit it has CMOS electronics. I like to ground myself out by touching something metal that is connected to the chassis before touching the display. It is generally better to disconnect the - side of the 12v aux battery before attempting anything electrical in the car. This will reset all ECU's and your radio memories, window positions to boot, but that's ok the car will re-learn everything in maybe two or three driving cycles anyway. Have the windows all the way up before removing - of battery. Or it can be a PITA to re cal the windows. Better safe than sorry!