Pneumatic door/trunk closing problem in my S-420

My 1998 S-420 has developed a recent problem whereby the pneumatic closing of doors and the trunk is non-operational. I had run into this once before and I happen to be in the dealership for a class-A service. The mechanic said he would "reset" it and sure enough, the pneumatic closing started workiing again. Is this something I can do myself? If so, how? Any help is appreciated.

the fuse for the door locks is under the rear pass seat it is the only 20 amp yellow fuse. you don't have to remove the seat it is facing the front of the car. if it is not blown you could try to remove it and wait 30 sec then plug it back in. if that doesnt work you will have to get a new vacuum pump for the locks.