It is the actuator on the locking mechanism. I just had the same thing happen to me. There is a leak somewhere. There is a small diaphram that is only held together by compression clips. They are prone to go bad. You have to remove the linning on the trunk lid and look where the actual lock mech. is and you will see what I am talking about. The only way to open the trunk now is with the actual key in you key fab. Insert it in to the key hole turn 1/4 to the left. Than all you have to do is push up/in and the trunk will open.

 

Try to reset the boot first, the instructions for this are in the owners manual.

 

I am having the same problem and dont have the manual handy. Can someone please tell me how to do the reset?

Thanks

 

Good point I forgot about that.

 

Thank You Both. Now I Can Try and repair the trunk:thumbsup:

 

Looked at the trunk release diaphram housing and found a crack. Used some superglue and a small piece of duck tape. Problem solved.

 

Good man; I used gorilla glue lol

 

same issue

I have the same issue, at least acording to the dealership, the diaphragm has a hole in it. They wanted eight hundred to fix it. I declined
Only opens with key, no buttons, nor remote. Closes fine though. They say the diaphragm pushes the lock open so the lifter can do it's job.

 

Does any one have any pics on how to fix the diaphragm? I have the exact same problem on my 02 S500.

 

So, I opened the boot of my e320, looked at the lock - which has a electric cable, tried to pop the felt lining off the whole inside but failed at that point due to the little black poppers being so well fixed... I take it, that I need to access the area around the handle / key - not the actual lock.

Any advise on popping the little black poppers?? or is it just brute force?

ps - the reset is apparently activated when the interior boot release button is held down for 20 seconds. - This made no difference on my car!

 

I was able to find my diaphram and take it out and see that it needs to be replaced. what is the actual name of the hockey puck with the diaphram in it so i can go purchase a new one and put it in the trunk? does anybody know the actual name?

 

2001 S55 Trunk Release problem only works with key

I have the same problem, the reset didnt help either. Does any one where the diaphram is, I am attaching a picture from epc

 

It is in the actuator, which is the white rectangular device in the pictures at http://www.benzworld.org/forums/w220-s-class/1554501-what-do-i-do-now.html

You replace the white actuator.

 

My truck problem was due to the wires not locking in to the yellow plug connected to the side of the door latch

 

But how did u manage to open the trunk?
I have been trying for 2 days now & can't open the trunk ....

 

I guess this is the problem now......
Trunk won't open even when the car is running with a jump start from the front....
Looks like the vacuum leak in the trunk locking mech.
Now the question is, How the trunk can be opened so I can change the battery?
It won't open with key.....
It won't open with remote.....
And won't open with the switch on the driver side door switch......
Even when the car is running......

Please help.
Appreciate your time & help.

 

A vacuum leak from the soft close mechanism would not prevent opening the trunk with the mechanical key. The mechanical key is (supposed to be) able to remove the lock mechanism from the central locking system altogether. Some members have not understood quite how the mechanical key functions, especially in the trunk lock.

For your model, put the key in, turn the lock 90 degrees counterclockwise and keep it there; and push the lock button (the silver button into which you inserted the key, not the plastic one) in (upward) to open while keeping the key in the lock. Be ready for this to set off your car alarm (have the Smartkey nearby). If you try this and the key just won't release the lock, try a little WD-40 in the keyhole.

The mechanical key operation is discussed on page 53 of your owner's manual, with a diagram. If you don't have an owner's manual (yes, I know it could also be locked in the trunk), try the direct link to the manuals download page, https://www.mbusa.com/mercedes/service_and_parts/owners_manuals. if that link won't let you in, see the links under "Manuals" in the W220 S-Class Encyclopedia sticky (http://www.benzworld.org/forums/w220-s-class/1508080-w220-s-class-encyclopedia-start-here.html) and register as an owner on MBUSA (it's free) - then try the direct link to the manuals download page. It's in the Encyclopedia writeup as well.

Also, you might check fuses - see http://www.benzworld.org/forums/w220-s-class/1219691-fuse-chart-2.html for the fuse diagram for your car (I know your fuse diagram is probably in the spare tire well, possibly wrapped around a tool, so you can't get to it); the fuse diagram link is also in the Encyclopedia (together with links to some other model years). In your '00, Fuse 62 is for central locking, and fuse 13 is associated with the trunk lock (also fuse 57 if you have auto open/close). That might restore the switch on the driver's door, as well as the trunk opening function on your Smartkey. You might find that a burned out fuse is the cause of the whole problem.

Hope that solves the matter.

 

Hello,
Thanks for the input...but it didn't help.
I put in the wd40 in the lock with a straw(comes with the can)...the key just don't wanna turn..almost broke the end...the plastic does gets pushed in but the key don't turn....
I have the mannual but the mannual online is little different....although I was reading in that there is a trunk release switch on page 64. Is there any way we can access it from inside the car....
I tried to pull down the passenger seats but couldn't, is there any access door to the trunk from inside the car.....

Also there is another post which talks about the fuses...I got it checked from a mechanic and all of them are fine. He checked with a tester...there is no no 13 fuse in the diagram?...
This is the link to the post ...
http://www.benzworld.org/forums/w220-s-class/1219691-fuse-chart-2.html
Can u help me point out that no 13. Was thinking to just replace the fuse and see....
Also today, my cluster panel lights are out...the shocks , air pump, emergency flasher etc.....they all don't work now...seems like the battery is getting weaker day by day...

Thanks for your time and help.

 

There is no access to the trunk from inside the car. Unless you have the "ski" option, the gas tank fills the entire space behind your back seat.

All I can advise regarding turning the key in the lock is play with it. If you can't turn it before pushing up, then insert the key and push up, then turn.

You have to read posts carefully. The fuse diagram I referred you to and that you posted above has a correction regarding fuse #16 in the post, just above the diagram. It is fuse #6, not 16. The row labeled F16-F27 is in fact F6-F27. Fuse 13 is in that row.

Sorry I can't be of more help. Getting into the trunks of these cars with a dead battery or after locking the only key one has in the trunk is vexatious. Your dealer may be of help; call and request Roadside Assistance. There are certain conditions regarding whether the service will be free. See http://www.mercedesroadside.com/por...c6813453/?&vgnextoid=f3226069047ee210VgnVCM1000007c184335RCRD&vgnextfmt=default

 

I have the same problem....but the key don't work either....

Is there any other way to open besides calling the locksmiths.....

 

Ok..
This is where I stand...
I Tried

Unlocking the trunk with the mannual key..doesent turns...... Didn't work

Put the key in driverside door handle and turn left for 30 seconds ..all doors are unlocked and windows roll down, sunroof opens...indicating everything is unlocked.............didn't open the trunk.

Of cource tried to reset and use the trunk open switch in driver door panel even when the car is running......... Didn't open the trunk.

Next...check all the fuses all are working fine...there is something..as per the chart for fuses here, I checked but I don't have the fuse no 13 in my fuse box....there never was....I am not sure if it's normal......but all the fuses in both the boxes under the hood are fine including in the box under the rear back seat (passenger side)

Took the bottom seat off and tried to lift the back seat out but couldn't as the head rests don't move down (for when I got the jump start first time..the power to the instrument panel is gone...not even for emergency light) so can't use the switch to roll down the back seat head rests.
Anyways, behind the back seat, there is an opening in the foam and a square plastic cover, took that cover out hoping there is the access to the trunk from there, but there is the Fuel Tank.... So no luck there.

Went to the FJ Benz dealer....they told me that the locking mech is bad, need to drill it out and put a new one in. Total quote.....parts 450 labor 400 or @ 140/ hr.

Now I am trying to find a local locksmith who can do the same for less and looking to buy the locking mech on online.

Is there something I haven't tried....or if there is anything else I can try, let me know pls... Another post I read , someone mentioned a lock smith and that they used some air cuffs like they use for BP monitoring.....haven't tried that yet....
Shall I try or let a locksmith check that...

Pls. Advice .... Have learned a few things here on the forum here....so thanks a lot to all who have replied in past to me.

Really appreciate you guys.

 

Trunk release diaphragm housing

Looked at the trunk release diaphragm housing and found it that cap is losing.
To put back it is no space to work on it. Do I have to take whole lock out and how I do that?

 

I can add that when i had a new key cut it wouldn't budge the rear barrel lock for weeks I added WD40 and white grease and kept putting the key in and trying to turn it, eventually the pins released themselves in the barrel and today it moves effortlessly and unlocks. I use the key every few weeks and always apply a drop of oil to avoid it seizing. When I first got it moving it was with a pair of pliers but don't force it beyond acceptable limits. I had almost given up when it freed itself.

 

04 S500 trunk won't opwn without metal key

My trunk won't open without using the metal key. The door trunk release light (red) is on when I open the trunk with the key.. Key FOB, trunk release on driver's door, trunk lid button next to trunk key opening do not work/open nor close the trunk, only the metal key works. Once I open the trunk with the key, I can move the key back to 12 o clock and remove the key, then close the trunk manually by pushing the lid down (gently) until I hear it latch but it doesn't close all the way down (assist) until I again, manually push it down the rest of the way (gently as opposed to slamming it). When I push any the following (no metal key inserted) key FOB, driver's door button, or the latch button next to the key slot, I can hear the latch attempt sound for about 5-10 seconds but the trunk does not unlatch and open. I have to get the metal key out to unlock it. So, can anyone tell me the best order of things to check starting with most obvious through the most likely "process of elimination" for an 04 S500 model? I like to tinker and figure things out for myself mainly for the satisfaction of having done it and secondly, for not having to go to the dealer due to cost of labor. My problem is that this is my only vehicle so I can't take things a part for a few days if they hamper my ability to drive the car to work everyday, hence, the most likely thing to try first/process of elimination since this most likely will take some time to chase down.

 

First thing to try is resetting the PSE system. Find the interior light behind the right rear passenger's heels. Pry it out, and remove the yellow fuse. Make sure that it is not blown, then replace it. If the system then works for a brief time, you have a pneumatic leak that you must find and fix.

 

Same problem here. Problem continues. The lock will not turn when I place the valet key in. Any help?