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As the title states, after work I opened my trunk to put some items in and tried to close it manually (by hand)... and it refused to latch. I tried a few more times (a little more firmly) to no avail. I then tried using the auto close button on the trunk lid a few times and that would lower the trunk, but it wouldn't latch and immediately flew open every single time.
Perplexed and angry, I gave up and drove home (not far) with the trunk open. When I got home and parked, I remembered the button on the driver's door to open/close the trunk. This worked. I haven't tried to reopen the trunk yet out of fear that it may not close again.
I've seen similar posts, with different symptoms, all pointing to the soft close motor. With the trunk not even closing manually, is that ruled out then? Or is the latch still electrically controlled by that motor even when manually closing the trunk? Any and all suggestions and help are welcomed, thank you in advance!
As the title states, after work I opened my trunk to put some items in and tried to close it manually (by hand)... and it refused to latch. I tried a few more times (a little more firmly) to no avail. I then tried using the auto close button on the trunk lid a few times and that would lower the trunk, but it wouldn't latch and immediately flew open every single time.
I have not had this with my recent E's, but my '03 S500 did this every once in a while, with the trunk open {obviously} hit the trunk open button on the remote which reset the latch mechanism
Perplexed and angry, I gave up and drove home (not far) with the trunk open. When I got home and parked, I remembered the button on the driver's door to open/close the trunk. This worked. I haven't tried to reopen the trunk yet out of fear that it may not close again.
I've seen similar posts, with different symptoms, all pointing to the soft close motor. With the trunk not even closing manually, is that ruled out then? Or is the latch still electrically controlled by that motor even when manually closing the trunk? Any and all suggestions and help are welcomed, thank you in advance![/QUOTE
I have not had this with my recent E's, but my '03 S500 did this every once in a while, with the trunk open {obviously} hit the trunk open button on the remote which reset the latch mechanism
As the title states, after work I opened my trunk to put some items in and tried to close it manually (by hand)... and it refused to latch. I tried a few more times (a little more firmly) to no avail. I then tried using the auto close button on the trunk lid a few times and that would lower the trunk, but it wouldn't latch and immediately flew open every single time.
I have not had this with my recent E's, but my '03 S500 did this every once in a while, with the trunk open {obviously} hit the trunk open button on the remote which reset the latch mechanism
Perplexed and angry, I gave up and drove home (not far) with the trunk open. When I got home and parked, I remembered the button on the driver's door to open/close the trunk. This worked. I haven't tried to reopen the trunk yet out of fear that it may not close again.
I've seen similar posts, with different symptoms, all pointing to the soft close motor. With the trunk not even closing manually, is that ruled out then? Or is the latch still electrically controlled by that motor even when manually closing the trunk? Any and all suggestions and help are welcomed, thank you in advance![/QUOTE
I have not had this with my recent E's, but my '03 S500 did this every once in a while, with the trunk open {obviously} hit the trunk open button on the remote which reset the latch mechanism
Yeah, I thought that maybe power cycling it did the trick, as I hadn't tried to start the car after the initial issue. I also thought that the car has not been outside in cold weather (25°F) in about a year. Not sure if that makes a difference, but it may be worth noting. Also, I remember about 3 months ago, the trunk opened on its own while the car was running in park. Didn't think anything at the time, just seemed weird.
Trunk not closing happened to me one night after work. For a completely different reason.
Got home - needed to get something out of the trunk - then it would not close manually.
It seemed like the weirdest thing - manual throw down and it would pop back up.
Then I noticed some one had backed into the corner my rear bumper - leaving a big dent in the plastic.
Everything was out of alignment till bumper repaired.
Trunk not closing happened to me one night after work. For a completely different reason.
Got home - needed to get something out of the trunk - then it would not close manually.
It seemed like the weirdest thing - manual throw down and it would pop back up.
Then I noticed some one had backed into the corner my rear bumper - leaving a big dent in the plastic.
Everything was out of alignment till bumper repaired.
That's a huge bummer, I hope they left their info (although it seems they never do)
The soft close you said is working, it's the electric latch that was malfunctioning, it should have reset if you followed the trunk open -hit trunk open on remote, Have you had more issues? I apologize, I'm a distillation and fermentation engineer with 30 years driving 12 different Benz's, Not a Benz mechanic.
The soft close you said is working, it's the electric latch that was malfunctioning, it should have reset if you followed the trunk open -hit trunk open on remote, Have you had more issues? I apologize, I'm a distillation and fermentation engineer with 30 years driving 12 different Benz's, Not a Benz mechanic.
My apologies for the delayed response.
No shade being thrown, not dismissing anyone's input. Tone is indistinguishable via text alone. Obviously, you took offense to how I worded my post. I'm sorry you took it the wrong way. I was simply hoping someone might chime in that works on these all day, everyday. Nothing more, nothing less. Everyone's input is welcome, including yours, and I appreciate it!
As stated, I have not reopened the trunk, fearing it may not close again. I live in an apartment complex and I'm not willing to risk that during winter.
I am curious about how the electric latch and soft close motor work together. From what I've read so far, I was under the impression that it's all one assembly. I'd really like to see pictures of how this all is assembled, but I haven't been able to find diagrams, pictures, etc. And during winter, I'm not going to tear it apart to find out the hard way. If anyone has any info about how it all works and/or pictures of what this all looks like, I'm all ears.
Again, I'm sorry if anyone took offense to how I worded my post.
No shade being thrown, not dismissing anyone's input. Tone is indistinguishable via text alone. Obviously, you took offense to how I worded my post. I'm sorry you took it the wrong way. I was simply hoping someone might chime in that works on these all day, everyday. Nothing more, nothing less. Everyone's input is welcome, including yours, and I appreciate it!
As stated, I have not reopened the trunk, fearing it may not close again. I live in an apartment complex and I'm not willing to risk that during winter.
I am curious about how the electric latch and soft close motor work together. From what I've read so far, I was under the impression that it's all one assembly. I'd really like to see pictures of how this all is assembled, but I haven't been able to find diagrams, pictures, etc. And during winter, I'm not going to tear it apart to find out the hard way. If anyone has any info about how it all works and/or pictures of what this all looks like, I'm all ears.
Again, I'm sorry if anyone took offense to how I worded my post.
well then I should apologize as well, I was not offended, so no need to apologize. I was trying to save you the cost of new parts and was trying to caution you that Benz's are different than other cars, things get discombobulated and fix themselves on many occasions. So with many cars you need new parts, with Benz's, it's usually something that resets itself or needs resetting. So all is good!
The soft close you said is working, it's the electric latch that was malfunctioning, it should have reset if you followed the trunk open -hit trunk open on remote, Have you had more issues? I apologize, I'm a distillation and fermentation engineer with 30 years driving 12 different Benz's, Not a Benz mechanic.
Are they separate? The striker/latch in the trunk lid, I thought, was only connected to the green emergency open button (via a cable). All the other actuations of the trunk via: FOB, trunk lid button, driver's door card switch activate the latch in the rear body panel.
[QUOTE=bmwpowere36m3;8227645]Are they separate? The striker/latch in the trunk lid, I thought, was only connected to the green emergency open button (via a cable). All the other actuations of the trunk via: FOB, trunk lid button, driver's door card switch activate the latch in the rear body panel. [/Q.b
Last edited by pierrejoliat; Dec 18, 2020 at 02:41 PM.
Reason: confused
I have not had this with my recent E's, but my '03 S500 did this every once in a while, with the trunk open {obviously} hit the trunk open button on the remote which reset the latch mechanism.
First post.
The soft close you said is working, it's the electric latch that was malfunctioning, it should have reset if you followed the trunk open -hit trunk open on remote,
Second post
?
Last edited by pierrejoliat; Dec 18, 2020 at 02:46 PM.
Maybe I was confused @pierrejoliat I thought your stating that its two different mechanisms/components. The trunk lid closing on the sedan is cable driven by the motor hanging under the parcel shelf in the trunk.
To me is sounds like either the latch mechanism is either stuck open and/or is being command to open (all the time or randomly). Again, a case where a bi-directional scanner might allow you to actuate the latch and see if its working. Or is the system being command to open when it shouldn't be. Inputs/Outputs/Powers & Grounds as Eric.o would say.
All good, I have a car with power closing and one without, the one without has a fixed latch bracket in the trunk sill and only has the open feature, my power close has the soft close latch in the trunk sill. I have other people closing my trunks all the time and the soft close feature doesn't like it when it's slammed closed manually from my experience with my "03 and '07 with that feature. with both those cars I was able to reset it with the remote so it worked again.
Function of trunk lock and electrical function diagram of trunk lid closing for a E550. Though the M14/31 "tailgate locking element" on a wagon is in the lid and the sedan its in the rear body panel (rear bumper meets trunk lid). Now as far as operation of closing... yeah, that's a lot of stuff communicating and needing to work.
The two mechanisms work together to close/lock the lid, @pierrejoliat you were correct . However I suspect the main "locking" function is performed by the catch mechanism in the trunk lid (M14/7) which looks like this:
I wonder if you could manually trip the rotating catch to the lock position, see if it locks into place, operate the unlock for the trunk and see if the catch releases. Door lock catches can get stuck either from being frozen, dirty or not fully being closed. If they are not fully latched, they won't unlatch (unlock) since some designs rely on spring tension.
Last edited by bmwpowere36m3; Dec 18, 2020 at 09:26 PM.
Reason: typo
Function of trunk lock and electrical function diagram of trunk lid closing for a E550. Though the M14/31 "tailgate locking element" on a wagon is in the lid and the sedan its in the rear body panel (rear bumper meets trunk lid). Now as far as operation of closing... yeah, that's a lot of stuff communicating and needing to work.
The two mechanisms work together to close/lock the lid, @pierrejoliat you were correct . However I suspect the main "locking" function is performed by the catch mechanism in the trunk lid (M14/7) which looks like this:
I wonder if you could manually trip the rotating catch to the lock position, see if it locks into place, operate the unlock for the trunk and see if the catch releases. Door lock catches can get stuck either from being frozen, dirty or not fully being closed. If they are not fully latched, they won't unlatch (unlock) since some designs rely on spring tension.
My '03 and '07 worked like that, you could manually trip the latch and open it with the door switch or the remote, don't do this with your fingers, I'm told it hurts! LOL. I don't know if this works on the 212, don't really want to try either!
My guess is once Meteo's trunk latched and closed, the mechanism reset and it's fine now, I understand his reluctance to try it based on his parking situation. I believe you are correct about the main locking function being in the trunk lid, but the latch in the trunk sill does the soft close function and in my experience is the mechanism that gets "discombobulated"
Last edited by pierrejoliat; Dec 20, 2020 at 11:00 AM.
OP says he has left the trunk closed since the problem showed-up. But I question whether the "incident" was just a one-off situation.
My keyless go trunk has failed to close only once. I recall my feet dancing below the bumper several times while pirouetting between trunk and grocery cart, before balking to close. I recall pushing the trunk close button without joy, then closed it with the driver's door button. Next time it worked like always, and it's been a couple months without any failures.
So I don't think this is a fatal problem, and encourage OP to challenge it to see if function returns.
Isn't this part of the fun of owning a Mercedes? The random stuff they will do one time and never again? Been a universal truth with all of my Benz cars. A few weeks ago my car's blind spot monitor indicator lights in both mirrors flashed continuously (but in a random pattern) on a 5 minute drive without the car giving any warning in the cluster. After a restart, it was gone.
With keyless go the car will not allow trunk closing if the key is in the trunk, we all know that. This has saved me numerous times when I had my keys in the luggage and when closing trunk it popped right back open, when I realized I had the keys in the bag.
But, how does the car know keys are in the trunk? It is somewhat a line in a water as it is some sort of radio signal to be sensed from where it comes from. How about if the car thinks keys are in the trunk while they are very close outside the trunk? This would explain why the trunk would close fine from the door switch as at that location keys are far away from the trunk in the driver’s pocket.
It has to have a proximity sensor in the trunk to detect the key. Every car I've had with these smart keys have had this same feature regarding not allowing keys to be locked in trunk.
I got the E550 into the garage for some work after finishing up the E350... I took a look at the trunk locking mechanism as I was disassembling, pulling the rear bumper to deal with blind spot radar and harness.
There are three parts to the closing and locking system (SEDAN): trunk lid/tailgate central locking motor(M14/7), trunk lid/tailgate locking element (M14/31) and trunk lid control drive unit (M51/3). The central locking motor (M14/7) is the "catch" and "lock" mechanism of the system (in trunk lid). The locking element (M14/31) is the "striker" and part of the "closing assist" (in rear center panel). The control drive unit (M51/3) is part of the "closing assist" (in trunk, under parcel shelf).
The wagon is similar, but different:
Striker is "fixed" in trunk floor (passive device)
Central locking motor contains part of closing assist mechanism
Tailgate locking element is in tailgate and connected to central locking motor
Here's what I observed:
Trunk Lid Open
Central locking motor catch is open (ready to engage the striker)
Striker in lower position (down, towards ground)
Actuate Lid Closing (inner trunk lid button or driver's door switch)
Control drive unit begins lowering trunk lid
Locking element raises striker (upward)
Central locking motor catches [striker]
Locking element lowers striker
-VS-
Trunk Lid Open
Central locking motor catch is open (ready to engage the striker)
Striker in lower position (down, towards ground)
Manually Closing Lid
Pull down trunk lid with enough force
Central locking motor catches [striker]
I'll take some pics when I have time... so I suspect the issue for @meteo7880 is that since he can successfully manually close the trunk lid, the issue lies in the locking element. Since it needs to "raise" the striker for the locking motor to catch. So then its either:
a sticky striker (dirt, lack of lube, too much lube, etc...)
cable broken (striker is cable driven by locking motor)
bad locking element motor
lack of input to locking element motor
Last edited by bmwpowere36m3; Jan 4, 2021 at 12:03 PM.
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The soft close you said is working, it's the electric latch that was malfunctioning, it should have reset if you followed the trunk open -hit trunk open on remote, Have you had more issues? I apologize, I'm a distillation and fermentation engineer with 30 years driving 12 different Benz's, Not a Benz mechanic.
