Benz Franklin

So the pneumatic closure feature of the trunk has not been working 100% of the time. I attempted to utilize the manual closing procedures but now the trunk will not close.
Am I correct to assume that by engaging the manual feature I have disengaged any automatic closing of the trunk? i so how would I be able to begin using the automatic closing features again?

Benz Franklin

I was able to fix the lock and it works just as it has in the past, the pneumatic closing system still isn't the greatest, but seems to be a common problem for this class.
I had to purchse a new battery since my uncle left the lights on when I went out if town and the soft close started working again, we'll see for how long.

next2pool

It's normal for the soft close to work again after a battery disconnect and re-connect. However, this is usually temporary since sooner or later the soft close will time out and shut off. This is almost always due to a leak in the latch mechanism or a hose.

Bugsi

I want to second the advice to *remove* the guts of the unit from its housing in order to better cover the ball-bearing ports with epoxy. There are two clips (indicated with blue arrows) that you can squeeze and then slide the unit out (and detach the hose that goes to the hockey puck diaphragm). There are SIX ball-bearing ports to glue (indicated with yellow arrows) on mine (from my 2005 S500 4MATIC). I see some people reporting that there are five ports, but mine has six, and it was hard to tell there were six without removing the unit from the housing.

ChristopherPJ

Hi Nick,

Firstly, thank you for the excellent tips! I drive a 2004 SL500 and while I have yet to try your fix, the soft close is just one of the problems I'm currently experiencing. Also, let me apologize now as I'm not too familiar with automobile mechanics.

Not sure if you would know but could a leak in the trunks pneumatic system cause a single wheel's ABC system (servos, level sensors) to malfunction? Could it possibly indicate if and where there may be a leak?

After being greeted with a front right lowrider and "ABC Visit workshop!" on a fairly regular basis, my temporary fix was to raise the car then lower it back down and it seemed to be fine. Until the next morning but sometimes longer. I then realized that it only happened when the "Close trunk lid!" warning appeared. (Note: My trunk does not fully close unless I slam it so.. there's that)

For the past two days, I've made sure the trunk was fully closed before parking it and I have yet to come out to a cripple.

Any thoughts?

Thanks in advance!
Chris

moretech

I had plenty of problems with my trunk lid closer until I used the above procedure to fix it. The car did not sag though at any time during the weeks it took me to find this forum and this great solution. And the closer is still working perfectly today ( last 5 months). I cannot be sure but now that I've had some time with my new car I do not think there is any connection to the ABC and the vacuum pump. I'm going to bet on a leaky pressure control valve but perhaps it will clear up on its own. You mention it is better now. You might try a fluid change as described in this forum. I have done this as a preventative measure as my fluid was discolored. I have not had any problems with sagging though before or after the fluid change. I hope it stays that way.


Moretech

Kenneth Oehmke

My main battery went dead and I had to use hard key to get into trunk to jump. Now I have a malfunction batteryou light onyears cluster and the trunk assist button stopped working. Do you think disconneciting the convenience battery and reconnecting would resolve my issue as well, Nick?

1054boston

4 weeks ago took apart the trunk soft close and tried the posted repair. As a professional tech I wouldn't attempt such a shade tree repair for my customers do to the high probility of a come back. But for my own cars I'm always looking for an inexpensive solid solution to fixes.

I have got to say MB World for this quick fix....

Kenneth Oehmke

When I got home, I disconnected the front battery, let it sit for a few minutes, and re connected. Everything reset and works perfectly again. Thanks for the info. Now I need to clear the malfunction light I'm my cluster. Looking for help on Google before I take it in to clear.

jtse

So, I just got a 2003 SL55 and I unplugged the 20amp yellow fuse, and voila the trunk auto closes. I was happy then on the 4th try to close, it stopped working and I can hear the air leaking.

Now, I'm thinking, ah sucks, I gotta fix this now and I'm looking at the pictures and stuff and looks like its doable but.....still unsure of my own handy skills.

The screws on mine in the 1st step looks a bit different. I'm not sure why. I wanna know if anyone has had a failed attempt???

another question is if you guys know if my year SL55 comes with soft close front doors as standard or not? Mine is currently not working at the moment, and I think it probably doesn't even have that function factory installed.

Jan T

If you are talking about that very first photo, those are just plastic clips that pull out. If you are talking about that photo with the two Torx bolts referenced on the latch, mine were Torx bolts. So if yours are different maybe someone changed them out. But if you do have Torx bolts, make sure you use a an appropriate Torx bit. I mistakenly used an Allen wrench, and striped one of those bolts and then was hell getting it out.

By the way, my fix is still holding up well after all these months.

1054boston

The battery in the trunk is the convience battery the one located in the engine compartment is the main battery for starting the car

1054boston

https://mbworld.org/forums/sl-class-...w-fix-diy.html

This link is great showing how to repair

megatron.

Thank you OP for a great writeup! I did this for my 06 SL55 yesterday. Glued up all the ports with gorilla glue epoxy and after 30 minutes of letting it set, I confirmed that there was no more air leak. I like the suggestion of turning on the pump briefly once before the glue sets in order to suck in some of the glue into the cracks. I disconnected the trunk battery to reset the pump and the trunk worked perfectly after that. However, the red light on my driver's door trunk button remained lit and I also had the associated 'trunk lid open' error in the dash. I tried pulling the fuse from behind the passenger seat, but this did not help. I opened and closed the trunk several times and this also did not help. I was running out of ideas and for some reason I thought I would try the a trunk key. I put the trunk key in and turned it (can't remember if i turned it halfway or all the way) and then the trunk light went off. However, the remote would not operate the trunk and the trunk release handle on the trunk lid would not work. The driver door trunk release would also not work. I rotated the key in the trunk lock a few more times and finally the trunk would work normally from the remote as well as the trunklid release and driver door release. The trunk open error also resolved along with the in-dash trunk open warning. Definitely try this if you are having the error message persist after the repair!!!!!

I also did the trunk strut replacement which took all of 5 minutes and the trunk no longer hits me in the head! $24/each from amazon.

As always, great info on this forum!!!

jtse

Okay, so today, I did a consumer battery replacement and the trunk worked for like 2 minutes.

However, I noticed two things. 1) When I drive I always hear a hissing sound of some air leaking form the back of the chair. 2) for the first time, I heard the hissing sound standing outside of the car right behind the trunk and hear the hissing sound even after the trunk is soft closed for seconds after.

Do you think there might be more than 1 leak going on? or am I hearing the hissing of just that one spot where this DIY guide is doing?

Can you hear leaking sounds if the DIY location of the leaks are leaking while driving?

J

next2pool

I never did hear any hissing before I fixed my latch. I suppose there are all levels of leakage. Mine would work 4 or 5 times after a reset. Now a year later the fix has held up perfectly.

nmumford

I followed NiKleinr6's excellent instructions and I would like to contribute the following advice. The most difficult part is to disconnect the rod with the cup and ball. You need to reach in and feel for about 3/16" rod. Once you find the rod follow it to the plastic cap. Then use a long screw driver to pop the plastic cup.

Reconnecting the rod is not any easier and you may want to reach in with a drift punch to push the cup on.

bigkev21

My soft close works fine. When I push my close button however, I hear the motor run, but does not move the trunk. Will this fix my auto close?

Jim SL55

Thanks for the awesome info, my trunk (boot lid here in Australia) wouldn't lock down....but after disconnecting and re connecting the battery it started to work again. Thanks for the tip and ill be off to get some epoxy asap.
Cheers Jim

moretech

I used this process 8 months back and it solved my problem


Moretech

bill morrow

THANKS to the OP for his how to fix it post..

pulled the ground cable from the "consumer", waited a minute, reconnected it and all is now well for as long as it works..

going to look into the trunk lid on my now retired and parting out '01 S600 to see if the trunk soft close part is the same..
and at least have a spare if the one on the SL55 goes bad..

hlmpk

For those of you who choose the fixing/patching route, you can go 1 step further (see pictures):


I remove this part from the assembly (it seems to only have 5 ports with the metal *****) - my car is an 03-SL55, original part I believe.



I went out to my local hardware store (Home Depot) and bought some fuses, and pipe cap!



I broke the fuse glass, ground its end to size. I also clamped the hexagon nut cap, and drilled it to size...



Each time, after I epoxied one end, I cappet it with the right cap, then epoxied over it one more time... Voila!





So... I installed the whole thing back in the car (I had not put everything back yet), and it worked great...

However, a couple days afterwards, I noticed some black plastic flakes in the trunk, so I removed the latch assembly to investigate, and found out the so-called black puck was loosing material. I tried to seal it with the same epoxy, and it did not stick. I went out and bought 3-4 different types of sealer, glue and epoxy and it still did not stick (I could seal it then tie it with a hose clamp or cable tie).

All these patches will work, but could potentially break down 6 months or a year down the road, and since the part is original and old, I do not want to take this chance and went out to the internet to buy a whole new assembly. Here is some info about the parts:

My car: 03 SL55 AMG

- Whole Trunk Lid Actuator Switch: A 230 750 00 85 (01 85 for the latest)
www.oemercedesbenzparts.com ($265 as of April 2016)

- Remote Control Vacuum Module: A 230 800 01 78 (Woco 01 2945-013013) (this is the main culprit with 5 ball bearing ends, I cannot find anyone on the market selling it - Only this one need to be changed)

- Air Servo: A 220 800 02 75 (KW16/03 - D108B) – Woco 400292 A/B
(many of you call it the "black puck" - could be bought separately)

- White container: A 220-800-05-75-M22 – Woco 400395
(serving as an air accumulator - could be bought separately)

Enjoy and good luck with all your DIY...!

hlmpk

skalade

Is it normal for the " White Container / Air Accumulator tank" to have air coming out around where the 2 pieces of the tank snap together ? Just curious. When I cycle the trunk closer I hear air from that part of the tank.

hlmpk

If you hear (or feel) a hissing noise somewhere, then there is a leak.
If your whole assembly is old, then change the whole thing - so you don't have to deal with it down the road when something else fails.
If you car is new (5-7 years old) or you think the latch is new, then just fix or change the part that fails. In your case, you can just buy and swap the while container (see part number on my post above).

Just want to remind folks who have a convertible that a working latch is very imperative! When you have your top down, and if it starts raining, and your latch doesn't function (for ex. your car detects a "trunk not closed"), you CANNOT raise and close your top!

hlmpk

Startech

For all those asking about having to unlock with the manual blade key-------