Can't switch to AUX input??
 

For some reason my AUX input is bypassed all of a sudden. I have the stock audio (non-nav) on my IS250 '08. It's always been working fine but now I can't even switch to it. Pressing the DISC/AUX button switches it to CD/MP3 so I know the button is not broken. Cycling through the MODE button on the steering wheel changes it to everything except AUX. What could it be? Dead fuse for AUX?

did you plug anything in the port?

Yes, tried both plugged in and unplugged. Before I would be able to switch to AUX even without anything plugged in.

i have the is250 and it wont go to aux unless i have something physically plugged into it. change the plug it might be damaged and try to use it again, if not the aux box might be messed up. i would just check to see if the connection is still good and the wire before trying something else. oh and also make sure the unit you are using is working proplerly or plug something different into it and see if it works

Likely a damaged cable. Replace it with another and see if your problem goes away.

As CANDYAPPLE says, that's not right. You should NOT be able to switch to AUX with nothing plugged in.

I believe there is a part of the jack that detects whether a plug is inserted. [I've observed that I can switch to AUX whenever a plug is inserted into the jack, even if there is nothing connected to the other end of the cable -- but if I remove the plug I can't switch to AUX] If replacing your cable with another one (make sure it has a 3.5mm plug, not 2.5mm) doesn't help, I'd suspect the metal finger in the jack that detects whether a plug is inserted may be broken.