99 (w140) s500 trunk door will not fully shut

May 12, 2020 | 02:18 AM

Drews s500

Thread Starter

Newbie

Joined: May 2020

Posts: 4

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99 s500

99 (w140) s500 trunk door will not fully shut

When I close my trunk door it will not fully shut. I would have to take the fuse out and put it back in for It to fully close.

May 12, 2020 | 05:37 PM

wizee

Member

Joined: May 2019

Posts: 213

Likes: 114

From: Waterloo, Ontario, Canada

'07 CL550

The trunk requires the vacuum operated soft close system to fully shut. The control computer for the electric vacuum pump will disable the pump if it fails to build the right vacuum pressure within a set amount of time. This is generally caused by a leak, either in a vacuum actuator, or an air line. Pulling the fuse and reinstalling it will temporarily reset the vacuum pump, allowing it to function (at a reduced strength) despite the leak, but doing this repeatedly will burn out the pump. You need to find the air leak and fix it so that the pump doesn't time out.

May 13, 2020 | 09:44 AM

Ekipe

Newbie

Joined: Feb 2015

Posts: 3

Likes: 0

From: Curitiba

W116, C124, W126, C219

Quote:

Originally Posted by wizee

Yes he is right. When you try to close the trunk put your ear close to the lock and probably you will hear a hiss sound.

Jul 5, 2020 | 12:15 AM

nishboo

Senior Member

Joined: Dec 2002

Posts: 348

Likes: 20

From: Florida

W124, W126, W140, W220, W222, R129

Quote:

Originally Posted by Ekipe

Yes he is right. When you try to close the trunk put your ear close to the lock and probably you will hear a hiss sound.

Any videos or diy on this? Mine does this too, and when it times out, the handle doesn't come out of the trunk anymore either.

I can hear an air leak on the latch side.