The Mégane II Owners' Club

Hi lads. I have MegCC 2005 1.6 16V. Recently I have installed a subwoofer and then the ignition in the car stopped working properly. Car starts fine. What I mean is normally to start the car u insert the card in the reader, select neutral gear, press the brake pedal and press the Start/Stop button. Now I dont have to press the brake or clutch pedals. Just insert card, select neutral gear and hit the Start/Stop. Car starts. I wouldnt notice but I wanted to close the windows and I selected third gear, pressed brake pedal and pressed the Start/Stop button. Cat should give just the power, ignition but it tried to start the engine (weird) but it didnt because the car was left on gear. Once I pressed the clutch it started (and it shouldnt). Also I noticed that 'Electronic Fault' comes up on the display and disappears itself. Wipers, lights, windows working fine so I dont think its the UPC box. Any ideas guys?

Sorry for my english.

Double check the connectors in the battery - tug them to see if any loose connection. You would be surprised even a little bit loose and errors throw up.