Trunk Lid Slams Shut Every Time
Thread Starter
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Joined: Aug 2005
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From: Covington, WA
'96 SL600, '05 S55 AMG, '06 C230
Trunk Lid Slams Shut Every Time
Been battling this problem for a while now - When using the automatic trunk closing activation, the lid travels down fairly quickly but does not stop until it slams into the latch and is physically stopped by the body frame. Because the lid travels 'too far', the normal soft-close function never gets a chance to activate. The soft-close function works correctly with the lid open and I can use a screwdriver to simulate the latch engagement. This is not an intermittent problem; it occurs every time. If I close the trunk lid by hand, the soft-close grabs the latch at the correct time and pulls the lid slowly closed. I have changed the PSE; same result, no change. Using Star, I normalized the trunk lid - no change.
Looking for any information on how the trunk lid 'knows' when to stop. If it were not for the physical body frame, the lid mechanism wants to continue travelling downward. In fact, the little trunk hydraulic pump keeps running for a couple seconds after the lid has completely slammed into place. This suggests that whatever tells the PSE to turn off the pump is not doing so. Any insight, especially from the MB Technicians, would be fabulous. Thanks in advance.
Cheers,
Jeff
Looking for any information on how the trunk lid 'knows' when to stop. If it were not for the physical body frame, the lid mechanism wants to continue travelling downward. In fact, the little trunk hydraulic pump keeps running for a couple seconds after the lid has completely slammed into place. This suggests that whatever tells the PSE to turn off the pump is not doing so. Any insight, especially from the MB Technicians, would be fabulous. Thanks in advance.
Cheers,
Jeff
Thread Starter
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From: Covington, WA
'96 SL600, '05 S55 AMG, '06 C230
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From: Cape town
not a merc
Hi there. There is no sensing mechanism as far as I am aware. Unlike the ML which has an angle sensor. Your problem Is most likely mechanical. Check the dampening struts that are fitted near the hinges they are extremely hard to compress. If one has collapsed or has lost it dampening action the boot will slam. And possibly also not stay up at times. Good luck
Thread Starter
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Joined: Aug 2005
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From: Covington, WA
'96 SL600, '05 S55 AMG, '06 C230
Thanks Russell for the thoughts on the struts. Both have been replaced within the last 3 months with MB-dealer parts. They were replaced to solve a lid-won't-stay-up problem. But the trunk slamming was occurring before I replaced them.
Cheers,
Jeff
Cheers,
Jeff
Thread Starter
Super Member
Joined: Aug 2005
Posts: 591
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From: Covington, WA
'96 SL600, '05 S55 AMG, '06 C230
It's as if the lid closing pump is activating for too long a time, or whatever mechanism/signal/timeout/whatever that is supposed to turn off the pump is not being triggered correctly.
Cheers,
Jeff
Cheers,
Jeff
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From: North Carolina
2003 S500 - Toyota Corolla (in the rain)
Jeff, I have a similar problem. The struts have been replaced and the trunk stays up. However, just as yours when I hit the trunk close button it seems to come down normally and then just before it gets to the point where it meets the latch it speeds up. It certainly has me and my buddie who is a specialist scratching our heads. If I find anything out I'll let you know.
Mine does the same exact thing but I have problems with soft close so I have been blaming it on that. Just got a pump from a different car and gonna swap it with mine. See what happens...
Thread Starter
Super Member
Joined: Aug 2005
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From: Covington, WA
'96 SL600, '05 S55 AMG, '06 C230
Cheers,
Jeff
MBWorld Fanatic!
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Mercedes
Trunk Lid Slams Shut Every Time
Is there a control module for the trunk closer? My W211 E55 was slamming the trunk lid and almost took your hand off. Turns out, as the trunk closer control module gets older, it slowly keeps getting faster and faster in slamming the lid. Replacing the module with an updated design, and the problem was fixed.
Thread Starter
Super Member
Joined: Aug 2005
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From: Covington, WA
'96 SL600, '05 S55 AMG, '06 C230
Thanks for the input Joe. To my knowledge, the PSE module receives input data from the trunk lid positional sensor and the latch assembly within the trunk lid. The PSE then sends activation signals to the trunk lid hydraulic pump. In theory, changing the PSE should resolve the issue. Problem is, I have changed the PSE module and it had zero effect on the situation. Also, Xentry/DAS suggests the correct parameters are being read by the PSE. To solve this problem, we need to know what triggers the pump to stop. Working back from that point will lead us to the failure.
Cheers,
Jeff
Cheers,
Jeff
I finally got around to swapping the pse pump. The problem still happens and it is exactly as you described it. If I lower it manually, it will allow the soft close to kick in and do what it is supposed to but if I press the red button to close it, it will slam down and not give the soft close a chance to work. I also replaced the shocks on the lid with new ones from the dealer since my lid wasn't staying open but it still does it.
Thread Starter
Super Member
Joined: Aug 2005
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From: Covington, WA
'96 SL600, '05 S55 AMG, '06 C230
-BUMP- Keeping this frustrating issue alive. Any additional input? Really hoping an MB Tech can chime in on how the trunk closing sequence works, specifically what triggers the trunk lid hydraulic pump to stop. That's the key to this problem - the pump is not being told to stop and keeps running, forcing the trunk lid to slam shut.
Cheers,
Jeff
Cheers,
Jeff
-BUMP- Keeping this frustrating issue alive. Any additional input? Really hoping an MB Tech can chime in on how the trunk closing sequence works, specifically what triggers the trunk lid hydraulic pump to stop. That's the key to this problem - the pump is not being told to stop and keeps running, forcing the trunk lid to slam shut.
Cheers,
Jeff
Cheers,
Jeff
Thread Starter
Super Member
Joined: Aug 2005
Posts: 591
Likes: 9
From: Covington, WA
'96 SL600, '05 S55 AMG, '06 C230
Cheers,
Jeff
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From: Montreal, Quebec
2009 E350 4M Avantgarde;mistress 2002 S600; wife 2014 C300 4M
Trunk functions
I went thru this a few years ago after I bought the car; my problem was that the car would not "go to sleep", and continue to draw about 800 - 1200 mA.
Took me a year to get it to work right (almost), with some help from Eric in China.
The hinge geometry is mental, and appears to wear easily.
The hydraulic pack brings the lid down, and there is a proximity sensor behind the actuator to know where the lid is (both opening and closing).
On the closing cycle a timing circuit is activated, that monitors how long between hydraulic closing and locking by the soft close (must be less than 10 seconds, otherwise you get a fault in DAS to that effect ..."time exceeded..).
The pump still runs while the soft close engages (!).
The lid stops must be adjusted such that the lid can "overtravel", so when the soft close releases, the lid goes up by a few millimeters.
If you search my posts here and on Benzworld you will find my posts on the trunk hydraulics and the lid adjustment.
Good Luck!
Took me a year to get it to work right (almost), with some help from Eric in China.
The hinge geometry is mental, and appears to wear easily.
The hydraulic pack brings the lid down, and there is a proximity sensor behind the actuator to know where the lid is (both opening and closing).
On the closing cycle a timing circuit is activated, that monitors how long between hydraulic closing and locking by the soft close (must be less than 10 seconds, otherwise you get a fault in DAS to that effect ..."time exceeded..).
The pump still runs while the soft close engages (!).
The lid stops must be adjusted such that the lid can "overtravel", so when the soft close releases, the lid goes up by a few millimeters.
If you search my posts here and on Benzworld you will find my posts on the trunk hydraulics and the lid adjustment.
Good Luck!
Last edited by kraut56; Oct 15, 2015 at 08:59 PM.
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From: Cape town
not a merc
I had a chance to check this closing system. There is no proximity sensor but there is angle sensor measuring lid position. There is a learning process on star. Also in actual values you will be able to see the full open position and also full closed position that the sensor reports to PSE. Also the boot catch sw must be functional for learning to be done. And of course mechanical gas struts in good working order. Guys have a look at actual values of boot position and report back
