soft close trunk lid

The SL has a "soft close" feature, where when closing, the mechanical latch is engaged, and then the system pulls the lid all the way closed

the last bit of pull in is accomplished by vacuum, the system that also moves the door locks.

If there are issues, the first thing to check is remove and replace the fuse, which is behind the seats in a panel.

The pneumatic pump in the trunk shuts down this function if a leak or other problem is detected. It’s a very common problem and the first thing to try is removing the yellow 20A fuse in the fuse area under the storage boxes and replacing it. This erases the pump memory so that it will re-enable the soft close.

Yes, the door locks are pneumatically controlled, so too is the fuel filler cap lock and the lock to the storage bins behind the seats. If you have massaging seats, they are powered off the same pump which is in the trunk on the left hand side underneath the pump which runs the roof.

I’m sorry, I am in the UK and was not sure if the bins are swapped around for the US. Since the CD changer in on your drivers side, they are not, so the fuses you are interested in are underneath the bin on your passengers side.

You can remove the floor of the bin by very gently pulling back on the tabs which are at the back of the bin and lifting. Be careful, if you overdo it, you will break the tabs.

You can then reach in and push the vertical trim plate at the front out from behind. You’ll then see the fuses, the one you want is yellow, 20A, about 3 or 4 over from the left. If the fuse is blown, replace it with a new one, otherwise just plug the fuse back in. You should hear the PSE pump in the trunk run for a short while. You can then check the individual functions, central locking, trunk lid soft close, massaging seats if you have them.

If the pump runs on after the soft close, you may well have a leaky valve. If nothing works, it’s likely the pump has failed, it uses a graphite rotor which is quite fragile.

Fuse F71 for the pump

https://benzbits.com/R230/Fuses/RearFuses/2002_06_01_Through_2004_05_31_RearFuses.pdf