In my 2008 non-nav is250 I have had intermittent problems with an unresponsive volume / power **** on the audio system. When it happens, the volume cannot be changed and the system can't be powered off. All I can do is change the mode and eventually the system powers off by itself. Then I power it back on and everything is back to normal. Of course this happens randomly and when I told my service advisor about it, he said the tech couldn't replicate the problem so they couldn't fix it

 

I've had this issue on and off for the past 2 years as well. I notice it happens when it's warmer out, which would be practically year round for you I would imagine. Also unable to replicate the problem when I go in...tricky lil bugger haha

 

No doubt, it happens a lot more often during the hottest part of the summer!

 

Ive had that happen to me, but its been awhile since...Weird!

 

Are you playing "burned" cd's? This happened to me before when I had a cd I made in the player. Remove the cd, turn the car off and back on and you're good to go..just don't use that cd again! just something to keep in mind...

 

Funny thing, I don't think I have ever played a CD in this car. I either listen to the radio or my MP3 player through the AUX input.