Problems with the pneumatic system can cause closing assist and door lock issues.Google+
Car Problem Reports
Mercedes-Benz S500 Closing Assist/Door Lock Issues Due to Pneumatic System Problems
Mercedes-Benz S500 Problem
Average Mileage: 129,974 mi (42,000 mi - 268,000 mi)
Visitor, 2003 Mercedes-Benz S500, 109,400 mi
The central locking system does not work from the smartkey nor from the interior buttons. The truck will not open with they key either. I replace the 20 amp fuse in the F62 space from under the rear passenger back seat behind the light. This did not solve the problem. I can hear the pump go on and off as I press the key but does not do anything. The headrests do not go down either when pressing the release button. Not sure if its a leak or not.
System fails to close doors. Removing fuse will make it work again (for an unspecified time period)
Visitor, 2003 Mercedes-Benz S500, 115,000 mi
I have a 2003 Mercedes S500 my doors want lock/unlock also my trunk want open unless I open it with the key but I have to manly shut it I also notice my massage sits are not working and the back headrest isn't working can someone please help me out with these issues
Visitor, 1999 Mercedes-Benz S500, 125,000 mi
ITS A REOCCURRING PROBLEM, A TEMPORARY FIX FOR MOST OF THE SYSTEM IS REPLACING THE FUSE IF THE PROBLEM CONTINUES FOR ONE ITEM AND NOT THE OTHERS (I.E. THE TRUNK STILL DOESN'T WORK BUT THE DOORS DO.) THEN ITS USUALLY PRESSURIZATION ISSUE AND EVEN THAT CAN BE A SIMPLE FIX IF YOU CAN FIND THE AIR LEAK.
Smart key won't open door, battery is fine. Can't unlock doors or trunk from switches inside. Blade key was working fine for several months, now would not totally release drivers door had to get roadside assistance to manually unlock.
Visitor, 1998 Mercedes-Benz S500, 85,000 mi
Can the Bosch Vacuum Supply Pump which assists with closing the doors and head rest be repaired or must it be replaced.
Visitor, 1995 Mercedes-Benz S500, 121,000 mi
I also have the same issue with tunklid
Visitor, 2002 Mercedes-Benz S500, 148,000 mi
Auto assist door closing and locking stopped working. Truck has to be manually opened. Patched a leak in the line but still won't work.
Visitor, 1998 Mercedes-Benz S500, 150,000 mi
Having the same problem with the car locking. First it was the trunk not properly shutting, then I could only lock the cab from the trunk, and now the trunk locl is not working. I replaced the fuse, which worked for a day. Now I leave my car unlocked all the time.
Visitor, 2003 Mercedes-Benz S500
failure in pse system...remote does not open doors are trunk of car.