Heatwave

Startech: It sounds like to me, you are trying to remove the inner cover from the lid of the storage area. Here is a picture of mine that might help.

Thanks for all that, Startech. I'll revisit mine tomorrow. Your picture is most helpful, and I really appreciate it.

Heatwave

Startech: I got to the rear fuse blocks by popping out the stowage box bottoms as you instructed. Many thanks for that ... I wouldn't have discovered it had you not told me.

So I pulled Fuse 71 (it was good, by the way), waited for about 5 minutes, reinserted Fuse 71, fired the car up and tried to raise the top. No joy.

Local MB guru told me to bring it in next Tuesday. This is how $100,000 cars become trinkets in a few years time.

cyglee

Heat: Are you still getting a trunk open dash message, preventing the roof to operate? Can you slam the trunk closed, and then operate the roof? I might replace that yellow fuse with a new one anyway. If all no go, I'm guessing a PSE pump problem. Keep us posted. Good luck.

Heatwave

Thanks, Cyglee. I disconnected the ground wire from the service battery early this morning. I'm going to give everything the rest of the day to "go stupid," as it were. I'll hook it back up later this afternoon and see if there's any change. And I'll replace that yellow fuse with a new one, as you suggested. Can't hurt.

But still ... on cars this nice and this sophisticated and this high-tech ... simple little things like a convertible roof that won't operate are abominations.

Heatwave

OK: hooked the battery up. No change. Rats.

I don't know how the great minds at MB work ... I was a lowly PE major. But you'd think some bright MB engineer would have looked at the convertible top as it was being designed and engineered and said to the design team:

"Look, sooner or later the mechanism that operates the top is going to fail. Design it so that it will fail in the up-and-latched position. The car has air conditioning ... the driver can operate his car with the top stuck in the up-and-latched position. But just in case the system fails in the trunk-stow position, let's add a simple jack-it-up method for raising the folded-up roof from the trunk and moving it to the up-and-latched position ... something like the process American pickup trucks have lowering and raising the spare tire. Widen the gas cap door on the car's hip ... add a point for inserting a simple tool (stored in the trunk) that, when turned, jacks the roof up and out and allows it to be latched shut."

A car this expensive and so well designed, engineered, and manufactured shouldn't be so vulnerable to a failure that could be catastrophic in a simple little rainstorm.

Heatwave

Another piece of the puzzle: the tow alarm button on the console is inoperative. ABC off/on and ABC up/down works perfectly well. Door lock buttons atop dash do not work. Can't find a defective fuse. Something else I noticed: I disconnected the negative cable to the service battery and left it unhooked for about 8 hours, thinking perhaps that might allow the trunklid soft-close to reset itself and start working again. It didn't. But disconnecting the battery did not cause the audio presets or the seat adjustment presets to lose their memory settings. These are puzzling cars.

Heatwave

Here's the verdict: SAM Passenger Side. P/N 230-900-16-00

Heatwave

All done. Replaced the PSE pump. Makes all the difference in the world. At last ... everything about the Vario Roof and door locking system is in good working order. What's next?

cyglee

Heat: So it was both a passenger SAM, and a PSE pump? Thanks for posting the followup, so we can all learn.

Heatwave

I don't know why the SAM was faulty. But Xentry kept reporting it as bad, so I replaced it. That made Xentry happy.

Xentry also told me that the PSE was dead. I replaced the PSE pump ... everything works perfectly, including the door locks. The Vario Roof moves more quickly and the trunk release/slow-latch system works perfectly ... all is well. Knock on wood.

Replacement of the PSE pump wasn't too bad. Hardest part was getting the hydraulic pump out of the way ... suspended it with bungee cords. A coupla blocks of air lines lead into and out of the PSE pump. Each block comes out of the old pump fairly readily readily ... plastic clip on the pump holds the blocks in place ... push the clip tab securing each block and it releases its respective block. Remove the PSE pump ... attach the hose blocks to the new unit and install it. Place the hydraulic pump atop the PSE pump. Done.

I plan on dissecting the old PSE pump just to see what it looks like inside. If there's anything worthy of note, I'll try to post pix here.

I'm leaving Thursday for a 2000+ mile trip to Trinity Site, in New Mexico, then to Carlsbad Caverns, back up into Texas to see Palo Duro Canyon, then back home to north Mississippi. All systems in my car are "Go." It better not let me down.

webuycarnotes

I bought a used trunk soft close assembly on ebay almost 3 years ago, and it finally started to leak and fail. Removed the unit and still had trouble finding where the air was leaking from, even after several sealing attempts with epoxy.

Brain storm: This is a sealed unit, so I hooked it up to an oxygen concentrator I had to provide a constant pressure AND PUT THE UNIT UNDER WATER IN A SMALL BOWL. No trouble spotting the leak location. Resealed with more epoxy and tested underwater again. Sealed now (no bubbles) and put the unit under a garage fan to make sure the epoxy was set AND the mechanism was dry. Reinstalled in car and works great. Just an idea to move things along.

Ken Silver

I've done all the reading, but haven't found this solution yet. I want to know if it can be done.

I have the red warning "Close boot lid." But even closed it still gives the warning, and a regular clicking from the rear tells me that I have the dreaded soft close air leak.

The indie tells me today, after physically getting inside the trunk and listening for air noises, what I already knew from this thread - that the actuator will need replacing.

After we discussed some options, I had a thought that we could seal off the soft close mechanism and have it operate as an ordinary boot. Indie thought this was quite possible and a cheap fix by just sealing up the various hoses.

But will doing this affect any other part of the car?

I don't want to go ahead only to find it stops the roof operation or something like that.

Thoughts please.

DieselMartini

There are micro switches inside the trunk latch, that monitor the state if the latch. Probably gone bad, or out of alignment. You would have to take off the latch and take a look.

Ken Silver

My indie says there is a hiss which means a leak. But the question I guess is whether sealing the hoses up will cause the microswitches to malfunction?

Rafdaddy

Necessity is the mother of invention and this proves how an easy solution can be found for a complex problem. Great Idea and I will try it today. Thank you.

Heatwave

webuycarnotes: I was a PE major, so I gotta ask ... what is an oxygen concentrator? I don't think I have one of those lying around the house.

Good solution. Glad it worked for you.

emcinnis

Heatwave: I think I may have the same issue as you had. While my trunk lid will operate it does not latch completely causing the trunk indicator on dash to show open and of course will not let the roof to operate. I have been able to close the lid if I slam down just at the end of the power assist. That allows the roof to work, until next time I open the trunk.

What was the part number for the PSE pump? I am not sure if I have a PSE pump, closing sounds more electronic than air. I have a 2008 SL550. Do you know if they changed the closing mech?

Heatwave

emcinnis: The p/n for the PSE pump is:

A 230 800 06 48 ... Vacuum Supply Pump

I do not know whether your 2008 model uses a pump different from the pump in my 2007.

I hope this info helps you. Please let us know how you get this resolved.

NiceMerc

Bought my 2004 SL500 about 18 months ago. Love the car, it's a lot of fun and I've learned a lot from everyone here as I've gradually had the gremlins sorted.

The car had the typical trunk not latching problem. Removing the fuse reset the pump and then it would latch, but only for a while. Same with the contour seats. They would give up, seemingly at random.

I assumed it was the soft close and bought a new one. Indie fitted it, but told me it hadn't solved the problem and he was seeing codes related to the seats, but nothing specific enough for him to pinpoint the problem, so he was reluctant to start hunting, not knowing how long it might take and how much it might cost.

The car went back in for a service and some minor work recently. I gave him everything I had learned here about PSE pump related problems and suggested he use a MityVac to chase the problem back and forward from the seats etc. He didn't sound too keen and called me the following day to say everything was done except this problem and he was still getting a generic seat code. I told him to go ahead and pull the seats and start tracking down the problem. I explained that slamming the trunk led to broken 3rd brake light, which resulted in leaks which... you know the story.

Knowing that I was serious and this was more than a minor inconvenience, he put a good tech on it and they quickly - before they took the seats out - found the problem. The leak was at the PSE pump itself and they could hear it. They pulled the pump but couldnt find a way to 'bodge' it, so they replaced it. it was an easy fix, if hard on the bank account.

Having lived with it a couple of weeks I'm sure it was worth every penny to get it fixed and have the soft close working reliably!

If anyone else has problems with this system and assumed it was the soft close, jumped in, replaced it and is still having problem, the advice you can garner from this thread is priceless. Get the codes, put your Sherlock hat on and start listening for the leak from the PSE pump and from the ailing component.

Thanks to everyone here for all the insights and shared experience.

Gary

theboogers

Has anyone in us done a automatic trunk closer install to solve this problem?

Heatwave

Has anyone in us done a automatic trunk closer install to solve this problem?

Guilty guilty guilty. But it didn't solve the problem for me. I had to replace the PSE pump to get my roof and trunk operations squared away. Your results may vary. Good luck, Mate.

Rudeney

I had a different problem with mine today. The trunk would not open. I'd pull the handle, but I'd hear hissing and the latch would not open. I removed the latch and found the problem. There is a diaphragm that controls the opening of the latch and the plastic where its housing snaps together was broken:



I took it apart to see how it works and discovered it was just those broken plastic tabs that held it together:



Seeing that, I just decided to put it all back together and secure it with zip ties:



All is well now!

Oh, and as an added bonus, with the trunk lid trim disassembled, I took the opportunity to begin the install of my backup camera. Hopefully I'll finish that tomorrow.

AthlonX

Just to add an idea to any others that struggle with this. I had mine repaired twice using this method and although it did work, eventually it failed yet again. As it is a known problem that will happen again and again even on a new part it seems i decided a different approach. There is a permanent way to fool this and have it all work regardless of a leak provided it is small cracking as is usual. I have connected a reset relay in line with the fuse that trips when it over runs. What happens is when the boot motor fires the control power wire to the motor activates a timer relay which goes open circuit after around 5 seconds and closes again. The relay basically makes teh fuse open and closed, same as rest it by pulling th epower. Bought the relay on ebay for 5.00. Never had an issue with it in 2 years now and my boot latch is well fubar. Maybe of help someone on here. The relay is connected in the fuse box area behind the drivers seat where the fuse is that eventually trips.

PS: Dont mess with the electrics if you are not competent and understand currents etc...

missjune

Thank you so much! Was told I over packed the trunk which caused the error and soft close to stop working! I reset by removing the negative cable and all is working. I will take in for message check and if I have a leak this post will enable me to make the fix! Thank you!!!! I have no auto
mechanic experience but everyone here makes anything possible! Just completed the vario roof flap fix yesterday!!

docwood

Still covered? I have a 2007.