1998 Mercedes Benz C280

[easygo]

I am having problems with my 1998 C280 Mercedes Benz on unlocking the doors with the remote as well as not being able to unlock the trunk nor the the gas tank cover. I cant even open the trunk with the metal key. All of the fuses are fine and new batteries have been installed in the remotes. I located a door unlock vacuum pump in the trunk. I just need some help on trying to help me resolve this problem.