I have a 2007 Prius with about 80K miles. In the past year or so, I have noticed that the audio system temporarily malfunctions particularly when the car is left outside in the sun for some time. For example, I just returned from an out-of-town business trip where the car was left in an airport parking lot for 5 days. After starting the car and beginning my drive home, I noticed that the radio worked fine but I could not engaged the CD/Aux function. Similarly, the power button did not function properly; I could not turn the radio off without turning off the ignition. This has happened several times before when the car was left all day in a parking lot out in the sun (I live in Southern CA.). After the car is driven for a while, the audio function returns to normal. Does anyone have an idea of what might be causing this problem? Thanks in advance for your assistance. John.
I have heard of others having trouble with the buttons on the front not working. Some have disassembled and cleaned the buttons. Not sure if it helped. The main thing is that, with all the electronics in the Prius, it absolutely needs to have reflectors on the windows if left in the sun. The heat can lead to quick death of the HV battery. So keep it cool by any means possible.
My guess is you cooked the stereo and mfd failure soon to follow. Like nH70 said I really hope you use a windshield shade. Because of the angle and cross section of the windshield its one monster solar cooker. Put a thermometer on the dash someday. The PRIUSHOP on this site sells a custom insulated & form fitted windshield shade. Mine has lasted almost 6 years of daily Florida sun use. It keeps the car cool (saves gas!!!) and the dash cool. And buying from the shop supports this site!!! PriusChat Shop : Toyota Prius HeatShield Sunshade - Front - $32.00 If I left the car at at an airport for days I would cover the entire dash with towels too. Without a shade your are par boiling the dash and the multifunction display. There's an amazing amount of electronics and ecu's under the dash all getting cooked on a daily basis out in the sun. I suspect the reason so many MFD's have failed is no one protects it from the sun and all the capacitors dry out. I have a MFD shade and a dash mat and a SHOP shade. My 6 year old dash looks new. I put the shade up even if I'm just going in the store. Takes 8 seconds. And make sure this is in place and extended in the back as it keeps the hybrid battery cooler also: 2004 2009 Toyota Prius Tonneau Cargo Trunk Rear Privacy Shade Cover | eBay And this really helps while you drive: Toyota Prius Sun Visor Hood for Your Display Screen Fits 04 09 | eBay I wouldn't buy a used Prius with a sun beat dash. Thats nothing but $$$ out the door down the road. To much expensive stuff under there.
Get the Prius Chat Shop shield. Helps keep the car cool, and saves the dash and underlying electronics from baking themselves to death! Plus it supports the site!