Help needed! Autoradio Kenwood KDC-W311

Hi all,

I have a Kenwood car stereo with auxiliary jack in my car. I have purchased the appropriate 3.5mm jack to connect my Sony MP3 player to it but I cannot get the stereo to switch over to auxiliary mode. According to the instructions, I just need to press the SRC button to switch between the various functions but all I get is "standby" and "tuner". The stereo has a cd slot but that does not come up on the list either. I don't actually own any cd's so I haven't tested it.

I have tried reinitialising the stereo to factory settings but nothing appears to work. Is there anyone technical out there who can advise?

Many thanks :)