http://caraudio.manualsonline.com/manuals/mfg/pioneer/pioneer_deh_dehp3100.html User submitted content regarding Pioneer Car Stereo System DEH-P3100 http://www.owneriq.net/images/sites/www.owneriq.net/logo_notag.gif http://www.owneriq.net 144 57 en-us Sat, 27 Jun 2009 22:32:18 -0400 240 http://caraudio.manualsonline.com/ex/thread/view/idThread/2200487?s=rss <em style="font-style: italic;">My unit was working fine until the car battery was changed. Then the unit stopped working completely. The stereo is in an 1989 Mercedes 300SEL. Is there an unlock code required? How do I get one if there is one?</em><br /><br /> <strong style="font-weight: bold;">Latest post, made on 2009-06-27 22:32:18</strong><br /> My unit was working fine until the car battery was changed. Then the unit stopped working completely. The stereo is in an 1989 Mercedes 300SEL. Is there an unlock code required? How do I get one if there is one? 2200487#2567607 Sat, 27 Jun 2009 22:32:18 -0400