Electric assist door close - PeachParts Mercedes-Benz Forum

Vinalf · #1 04-26-2002, 09:49 PM

Hello everyone,

I have a problem in that one door on my 1992 (W140) SEL will not close properly.

THe electrically assisted dor closing mechanism is not working.

Before I pull the thing apart, can anyone give an idea of what I should be looking for and where??

Thanks in advance to all.

Vince
1992 600 SEL

Gilly · #2 04-26-2002, 10:10 PM

Go to the rear fuse box (in the trunk on the right side panel) and locate fuse 9. Pull out fuse 9 for at least 10 seconds. Reinstall fuse 9 and see if that fixes it.
Gilly
ps The closing assist is technically considered vacuum powered, however the vacuum pump that operates the system is electrically operated.

Vinalf · #3 04-26-2002, 10:19 PM

Thankyou. It is all fixed. You are a miracle worker!!

Vince

riske · #4 04-26-2002, 10:39 PM

I had the same problem on my W140 not too long ago. Pulling the #9 fuse would fix the problem for a while but this fix would only last a few days and the problem would return.
I finally replaced the closing assist pump and that solved the problem for good.
The pump is easy to get to and easy to change.
Bill

Gilly · #5 04-26-2002, 10:41 PM

Vince:
Glad it worked. There is a safety circuit where if the closing assist pump doesn't see the microswitch close in "X" amount of time, it will cut out just that particular circuit. Removing the fuse resets the safety feature. There could have been something jammed in the door that prevented the switch from closing (possibly a seatbelt retractor is getting slow), or there may actually be a problem with that particular door. Bottom line is this may be a temporary fix, if it cuts out again sometime soon, you may need to have it looked at.
Gilly

euro 287 · #6 04-26-2002, 10:54 PM

If you have the closure assist repaired in the future make sure they do the modification on trunk closure assist. This will provide faster closure assist of the trunk and put less strain on the closure assist pump.They use the PSE pump for the trunk instead.
Ref # MBNA 72/11a

arif · #7 06-09-2002, 04:12 PM

l have the same problem....the trunk and rear door problem keeps reappearing and resetting fuse #9 fixes it temporarily. is it easy to replace the pump?? is there only one pump or one for each (trunk , doors).
thanks

euro 287 · #8 06-09-2002, 06:22 PM

The new pump should come with a modification kit if not then you will need to get one. Remember to do the mod to the trunk closure assist. This will prevent any strain on the new pump.

riske · #9 06-09-2002, 09:28 PM

The pump is located in the trunk directly behind the rear seat on the left side. Just pull it out , dis-connect the electrical connection and the vac. lines and re-install the new one.

euro 287 · #10 06-09-2002, 09:30 PM

The ref# was referring to the bulletin # provided by Mercedes. Now the pump is located in the trunk where the back panel goes against the rear seat. After you remove that panel you can look on the drivers side and you will see a foam package that has a pump in it. Now as for the conversion I was thinking of the central door lock pump ( it gets modified) . Closure assist pump is a straight plug in . I can fax you the modification for the trunk closure assist that we are doing for less strain on the motor .It has the part numbers and instructions for this procedure.

Gilly · #11 06-09-2002, 09:56 PM

Someone will have to check, but i believe the modification that's being discussed is just for the first few years of 140 production, later models implemented this change in production. I'm also thinking this isn't actually for the trunk pull-down, it's for the retractable hand grip, the handle that you're supposed to pull on to close the trunk. The source of pneumatic supply changed from the closing assist pump to the central locking pump.
Gilly

daddiojiggy · #12 06-09-2002, 10:31 PM

can you provide a little more info on that pump mod and is it a mod you do to the replacement pump or do you use an alternate pump?by the by,what was that ref# all about?

arif · #13 06-10-2002, 12:05 AM

thanks for all this useful info....
one question...how do l know the pump is bad, it still seems to come on when the door assist is needed.......l can hear it. Can the problem be something else since the pump seems to be working? ......or am l missing something here.

thanks in advance.

riske · #14 06-10-2002, 02:33 PM

It could be a vac leak at one of the lines or fittings. The easy way is to take a known good pump from another car and install it in your car, if that solves the problem then you know its the pump.
BILL

arif · #15 06-30-2002, 09:20 PM

Riske,
l looked still can't find the pump...can hear it coming on...how to access it from the trunk...l dont see any obvious openings.....
can anyone help??????????..any pics???
thanks in advance.