Closing Assist/Door Lock Issues Due to Pneumatic System Problems on Mercedes-Benz S320

Problems with the pneumatic system can cause closing assist and door lock issues.

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Average mileage: 133,407 (40,000–273,000)
6 model years affected: 1994, 1995, 1996, 1997, more1998, 1999
59 people reported this problem
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Viewing 1 - 20 of 34 problem details
1998 Mercedes-Benz S320 155,000 mi,
AUTOMATIC LOCKS DON'T WORK AND CAN'T LOCK DOORS USING CENTRAL LOCKING SYSTEM
1999 Mercedes-Benz S320 246,887 mi,
I have to manually push all rear and passenger doors locks down. Then use the ignition key to lock the driver's door. I got to manually slam the trunk down and then lock trunk w/ ignition key.
1996 Mercedes-Benz S320 95,000 mi,
Easy fix for this problem. Access pump at back of trunk and check air lines for tighness. Can adjust amount of tension applied to doors and trunk. Search web for exact fix but very easy fix.
1999 Mercedes-Benz S320 165,871 mi,
can not unlock any door. levers only go up half way but not fully up it almost feels like not enough air to push em up. trunk opens fine
1999 Mercedes-Benz S320 160,000 mi,
Closing Assist, drivers Door Issues Due to known reason.
1996 Mercedes-Benz S320 144,215 mi,
Intermittent door/trunk closing assist. Found that pulling fuse and re-installing would resume proper function. Currently researching specific cause. Suspect relay or switching device in system.
1995 Mercedes-Benz S320 154,332 mi,
door locks dont work with key or button trunk wont open with button inside car rear backup bars in rear quarter pannels wont go down
1994 Mercedes-Benz S320 120,230 mi,
power locks don't work and trunk,Closing Assist/Door & trunk
1995 Mercedes-Benz S320 89,000 mi,
Problem began with a battery that does not hold a charge.
1995 Mercedes-Benz S320 80,000 mi,
3 doorlocks do not open close with remote need to manually open seats dont move rear view mirror doesnt move trunk lid tongue remains stuck in out position
my central locking system is not working, I have to unlock the doors manually.
My locks are not working except with key or manually, and the lil piece on the trunk won't go in
1996 Mercedes-Benz S320 95,000 mi,
door lock or unlock not work but light work
Doors will open atfer being unlock with key or remote
1996 Mercedes-Benz S320 101,000 mi,
had to use trunk to lock and unlock car also driverside window regulators went out.
The central locking system on my 1999 mercedes benz S320, is not working, I have to unlock the doors manually.
Door locks activate when (only door lock) opens and closes all four locks.
1999 Mercedes-Benz S320 144,540 mi,
I have to manually lock and unlock all doors. Then use key to lock drivers side door.
1999 Mercedes-Benz S320 90,000 mi,
Just quit on me. Have to unplug the fuse every now and then to close the trunk properly.