I really need some help. I don't know much about Mercedes. I run an auto repair shop. The car was towed to my place, because of the battery being dead - since the battery was dead - they couldn't get in the truck. I hooked up a spare battery to a fuse and opened the truck. Tried to jump the car, but that didn't work. If you put the key into the iginition - nothing happens - no sound - However, all the lights and electronic devices work - the radio reads code though - Don't have a clue what that means. I do know it can't be the battery, if everything else is working. Is it some kind of immobilizer that is in place that isn't letting start the car? Could the key have to be reprogramed for some reason or another? Any advice would be greatly appreciated. Thank you.