SL-Class (R230) 2003 -- 2012: Discussion on the SL500, SL550, SL600

SL/R230: Trunk soft close - replaced but still fails

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Old Feb 25, 2016 | 06:12 PM
  #1  
NiceMerc's Avatar
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C300 and SL500
Trunk soft close - replaced but still fails

Hi everyone,

Great forum, super information. Thanks to everyone!

I've had a 2004 SL500 for 4 months now. Love the car, but it has some of the usual problems. The trunk soft close wasn't working, so based on the info here I bought a new unit and asked my mechanic to fit it. He did, but it's still failing. If you pull the fuse it will work 4 or 5 times and then fail again.

The mechanic said he thought the driver's seat lumbar support might be leaking and that would cause the new soft close to stop. I told him to leave it for now, so I can investigate.

The door locks and lumbar support are still working, so I think the pump is OK.

I'm pretty sure I read that if the soft close leaks it will be isolated from the other functions, so I think the problem is at the soft close end of things.

Anyone had a similar problem after fitting a new unit or repairing an old unit? Any pointers as to where the leak might be? Is it more likely to be connections at the new unit or hoses between pump and unit?

Any suggestions appreciated. I would really like to get the car in top condition.

Thank You
Gary
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Old Feb 27, 2016 | 04:09 PM
  #2  
moretech's Avatar
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From: amarillo texas
2003 sl 500
trunk closer

I'd be real tempted to double check the new units installation 1st. You might pull the fuse and check the lumbar both sides, if both still do something I think the closer is not in right or a hose is not plugged into the closer all the way.


moretech
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Old Feb 27, 2016 | 10:22 PM
  #3  
next2pool's Avatar
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From: Chandler, AZ
2003 SL500, 2016 ATS, 2016 CTS 2015 Volt
Originally Posted by NiceMerc
Hi everyone,

Great forum, super information. Thanks to everyone!

I've had a 2004 SL500 for 4 months now. Love the car, but it has some of the usual problems. The trunk soft close wasn't working, so based on the info here I bought a new unit and asked my mechanic to fit it. He did, but it's still failing. If you pull the fuse it will work 4 or 5 times and then fail again.

The mechanic said he thought the driver's seat lumbar support might be leaking and that would cause the new soft close to stop. I told him to leave it for now, so I can investigate.

The door locks and lumbar support are still working, so I think the pump is OK.

I'm pretty sure I read that if the soft close leaks it will be isolated from the other functions, so I think the problem is at the soft close end of things.

Anyone had a similar problem after fitting a new unit or repairing an old unit? Any pointers as to where the leak might be? Is it more likely to be connections at the new unit or hoses between pump and unit?

Any suggestions appreciated. I would really like to get the car in top condition.

Thank You
Gary
You are on the right track in that the soft close circuit is being isolated. I suspect you may have a leak or split in the hoses going to the latch. I epoxied my latch per this thread about 2 years ago and it is working flawlessly.
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Old Mar 4, 2016 | 05:37 AM
  #4  
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2005 SL350
I just went through something similar with my 2005 SL350. I tried the excellent repair instructions for the soft close mechanism from this forum and reinstalled the repaired unit. I reset the pump by unplugging it. It worked twice and quit. During the failures my lumbar supports, door locks, glove box lock, and behind seat box latches all worked. The soft close mechanism is definitely on a separate circuit in my car. You can verify this by tracing the hoses that go into the pump.

Frustrated I forked out the cash for an new soft close mechanism from the dealer. I replaced the old unit, reset the pump, and everything has been working fine for the last two weeks. I ws careful to be sure the new unit was mounted in exactly the same place as the old one, and used the bar from the old one to be sure it was exactly the right length. I was careful to ensue the sealing washer on the air hose connection to the soft close mechanism was in place, and that the connection was fully clipped in place before closing everything up.

Hope this helps.
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Old Mar 4, 2016 | 12:27 PM
  #5  
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C300 and SL500
Originally Posted by davies.thomas
I just went through something similar with my 2005 SL350. I tried the excellent repair instructions for the soft close mechanism from this forum and reinstalled the repaired unit. I reset the pump by unplugging it. It worked twice and quit. During the failures my lumbar supports, door locks, glove box lock, and behind seat box latches all worked. The soft close mechanism is definitely on a separate circuit in my car. You can verify this by tracing the hoses that go into the pump.

Frustrated I forked out the cash for an new soft close mechanism from the dealer. I replaced the old unit, reset the pump, and everything has been working fine for the last two weeks. I ws careful to be sure the new unit was mounted in exactly the same place as the old one, and used the bar from the old one to be sure it was exactly the right length. I was careful to ensue the sealing washer on the air hose connection to the soft close mechanism was in place, and that the connection was fully clipped in place before closing everything up.

Hope this helps.
Thank you, useful info and a couple of things to check with my mechanic.

Gary
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Old Mar 4, 2016 | 01:21 PM
  #6  
next2pool's Avatar
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From: Chandler, AZ
2003 SL500, 2016 ATS, 2016 CTS 2015 Volt
Originally Posted by davies.thomas
I just went through something similar with my 2005 SL350. I tried the excellent repair instructions for the soft close mechanism from this forum and reinstalled the repaired unit. I reset the pump by unplugging it. It worked twice and quit. During the failures my lumbar supports, door locks, glove box lock, and behind seat box latches all worked. The soft close mechanism is definitely on a separate circuit in my car. You can verify this by tracing the hoses that go into the pump.

Frustrated I forked out the cash for an new soft close mechanism from the dealer. I replaced the old unit, reset the pump, and everything has been working fine for the last two weeks. I ws careful to be sure the new unit was mounted in exactly the same place as the old one, and used the bar from the old one to be sure it was exactly the right length. I was careful to ensue the sealing washer on the air hose connection to the soft close mechanism was in place, and that the connection was fully clipped in place before closing everything up.

Hope this helps.
I think the repair procedure works for a lot of the failures but I suppose the latch can fail in other ways. When the unit fails that portion is isolated from the pump but luckily other components will still function as long as the pump is OK. I had my SL for 6 months before I even realized that it had a soft close. I just used to slam it shut like any other car. In my case, the repair worked
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Old Mar 7, 2016 | 12:29 PM
  #7  
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From: amarillo texas
2003 sl 500
Great topic , I too did not even know I had a soft close for 2 months after I bought my car. Slammed it good, very irritating--till I found the FORUM!! Works fine 8 months now. No resets of the fuse(and good luck finding where that is too without forum help)


moretech
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Old Mar 10, 2016 | 11:56 PM
  #8  
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2003 E55, 2003 SL55, 2014 CLS63, 2018 q50 Redsport, 1968 Camaro SS, 1999 Trans am Firehawk
if you have a STAR tool it will tell you what PSE leaks you have and exactly where they are coming from
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