Hi, I am hoping someone can help, we have a similar problam to another tread with our car. It is an N reg E320 Avantgarde AMG . Over last week end it was kept in our workshop, when we came in on monday we heard a low pitched wawa noise. On closer inspection we found that the vehicle battery had run flat. We charged up the battery.We have no problem starting the car. We can only use the key fob when sat inside the vehicle and within 3 inches of the interior mirror to set the alarm and lock the car. All was working ok before the vehicle battery went flat. The first thing we did was to change the batteries in the key fob and check the infa red signal, this is all ok. We resynchronised as per instructions in the owners manual. We have the original certificate of installation and found it to be from Scorpion. I emailed them and they told me the alarm is now obsolete but he very kindly sent us a wiring diagram. We have had the car running to try and charge the siren battery (someone had told us to do this) so far no joy.Apart from taking out the system does any one have any suggestions onhow to rectify this? many thanks Lin