This thread sounds like a mixture of Eco Mode and aftermarket stereos. 1. Eco Mode is a low battery or an electrical issue where you can simply disconnect the battery, reconnect and away you go. Make sure you give the battery a good charge. This happened to me when I left the lights on. 1. Aftermarket stereo. DO NOT assume that because because the stereo works fine without an adaptor, the car will like it. It won't . You need ISO lead PC2-32-4 because citroen use different things using the same wires so if you simply connect a new stereo to the car it will mess things up. Your central locking won't work after 20 mintues, your display might say eco mode and you stereo might forget its memory after an hour.