search this forum and google, there is literally thousands of posts on this.
You probably have a leak in your air control unit inside the rear trunk lid. You need to remove this, test by pressing the trunk release and then glue any cracks.
To get you going you can reset the e-fuse that has triggered, just pull the fuse behind the drivers seat, either number 54 or 71 depends on car., however its a yellow 20A. Replace fuse after 15 secs and it should work once more.

 

search this forum and google, there is literally thousands of posts on this.
You probably have a leak in your air control unit inside the rear trunk lid. You need to remove this, test by pressing the trunk release and then glue any cracks.
To get you going you can reset the e-fuse that has triggered, just pull the fuse behind the drivers seat, either number 54 or 71 depends on car., however its a yellow 20A. Replace fuse after 15 secs and it should work once more.

Thanks
I disconnected the consumer battery & that reset it. I searched & found the air leak thread so I suppose that's the way forward

 

You should also be able to run actuations with SDS. It should direct you with a proper diagnosis.

 

Not sure what the SDS is??

 

SDS is a $500 tool that will save you tens of thousands of dollars if you are willing to work on your own car. Fascinating tool!

 

Willing and capable... ;-)

 

Hi! I have the same problem with my 2003 SL. Boot lid is now open/up and i have tried to unhook the battery and fuse, but nothing helps. I dont hear anymore any noise, last week i could hear the air leak. Is there any way to get the boot lid down? Do i need new pse pump or just a new trunk latch mechanism?

 

Do you have any PSE functions that work (door locks, central locking, seat bladders, etc)? If not, check the fuse and make sure that it didn't blow.

Removing power from the PSE should have reset it, so something else may have gone wrong.

 

Just checked the fuse once again and it’s ok. First time when i reattached the fuse, i could hear the sound of air leak under passenger seat. Nothing happens anymore. Door locks, seat bladders are all out of order.

 

We have a hole forum dedicated to diagnostic tools:

Diagnostic Tools

Discussion forum for all Mercedes-Benz diagnostic equipment. Moderator - rudeney

www.benzworld.org

Here's my info on how to build your own SDS setup:

https://benzbits.com/docs/DASInstall.pdf

 

In case you need a video help on the fuse reset for the pneumatics, here is one I made earlier...

 

Thanks for the answers. Trouble has not been solved yet. PSE pump works fine, tested it yesterday. I was thinking if trunk latch actuator is gone, does all the pneumatics go down? Door locks, seats and nothing is working. Fuse reset and battery reconnect doesn’t help.

 

Not sure but I highly doubt that, the system is segmented, if the trunk is dead the doors should still lock fine... not an expert but I think the system can separate individual segments...

 

Not an expert here either but - when you reset the pump by pulling the fuse out for 15 seconds, then reinserting it, everything that is not broken, will work.

But once you use the thing that's broken again, the pump will time out after a certain number of seconds of not working and shut itself offline, so then nothing that uses the pump will work again, until you reset the pump by pulling the fuse out again for 15 seconds.

The scanner will dutifully report all the things that aren't working/online when the pump shuts itself down, but is not actually helpful in telling you exactly where the leak is. What you have to do is reset the pump, and see what works, until you hit the thing that doesn't work.



For example, here are all the failures my tool is showing me right now, but when I reset the pump, the only thing that won't work is the roof opening. Once I try the roof, everything stops again until I reset the pump. So just have to figure out where the leak is to the roof. Can only find a little fluid right under the pump itself, don't find any other leaky areas yet.

B1021 Control Unit A37 (PSE Control module (combined)) is not transmitting data on the CAN bus

B1264-017 – Leading Assist Raised/lower limit switch): limit switch “down” not operating or has cable break

B1438-12 – The safety time has been exceeded for the following pneumatic branch – Multicontour backrest

B1442 – The safety time has been exceeded for the following pneumatic branch – Trunk Lid

B1436-12 – The safety time has been exceeded for the following pneumatic branch – Left Front Door

B1436-15 – The safety time has been exceeded for the following pneumatic branch – Right Front Door

B1438-13 – Continuous cutoff of Multicontour backrest: the safety time was exceeded 5 times

B1436-18 – The safety time of the central locking has been exceeded for the following pneumatic branch – internal circuit of central locking system

 

 

Suddenly last week i charged trunk battery and moved car out of the carage and back, and pushed trunk lid button and it closed! I dont think it’s because of bad battery cause i renewed it few months ago. But now it’s easier to drive somewhere to check the codes with SDS.