So first off here is the problem I'm having and a possible solution and Route I'm wanting to go with the car unless advised otherwise.

So I know these cars fairly well. When I bought this car I got it for a very good deal. Upon inspection of the car I knew there was already a leak in the PSE Central Locking System vacuum pump when buying the car one of the cables that opens up the trunk was cut so when you would open the trunk you would hear the vacuum hissing, it's invisible cut that you can see. Whoever had the car before me knew there was a problem with that so they converted the trunk to Springs versus having the actual pump and lock mechanism open the trunk. Also when I first got the car all of the central Locking System worked perfectly fine on the key fob and inside the car, the headrest would fold down perfectly fine and go back up perfectly fine, the rear sunshade work perfectly fine, the passenger door suction door works fine however like I said the trunk did not work because of the line being cut and converted to Springs and the driver side door did not suction so there must be something wrong or another line to cut to that door as well I'm not sure.

Now that all that is out of the way here is what's going on this morning when I went to go unlock my doors they unlocke, but when I went to go lock them it would not lock to the key fob and I wasn't sure what was going on it wouldn't unlock or lock. So I sat inside the car trying to use the central Locking System button that wouldn't work my rear sunshade would not go up all this points to the PSE pump. I checked fuses in the rear Sam and all seem to be in working order. Also key fob works... It still sets alarm and all lights blink when setting or disarming alarm!

Now this is my solution and route that I was talking about that I may want to go with the car now I have found a used pump on eBay that I could easily replace myself and I have been advised since it's not a new pump I would not have to reprogram it, however if it was a new pump I would have to reprogram it to the car. I was wondering about deleting the whole PSE pump all together and just getting an aftermarket alarm so that I can unlock and lock my car, would that work? Because in all honesty I don't care to have the vacuum doors and the headrest being able to go up and down however I would like the rear sunshade to work and I didn't think that was connected to the PSE unit.

I know this is a very long post but I'm just trying to get some input before I put money into the car. Thank you very much hoping someone can help here.

Come on isnt there anyone who can help me or give some input???

maybe to make it simpler what I'm really asking is since my PSE vacuum pump Central Locking System is not working and the key fob will not unlock or lock my doors can I get an aftermarket alarm so that my locks will unlock and lock with a new key fob the top aftermarket?

I get your frustration - but, I think you are exploring a path no one has any experience.

My car - same model/year as yours - experienced some of the same issues. When I got the car everything worked except the soft-close on the driver’s side. Then, I couldn’t lock the car with the key fob. Followed by not being able to unlock the trunk. Then, I was blowing the fuse for the pump.

When I finally decided to replace the driver’s door locking mechanism - it was decidedly shot. Huge leak due to the cracked vacuum housing. Once it was replaced, all worked fine except the trunk. It was intermittent in deciding to work or not.

I removed the pump housing and tore down the pump. It actually didn’t look too bad. The motor and vane pump is a small part of what’s in the box. The rest is electrical solenoids for the individual vacuum lines. Seemed like lots of opportunity for an electrical issue somewhere. So... I bought and installed a new, complete vacuum pump box.

Everything worked perfectly.

Bottom line... my input would be the issue is probably an easier fix than you might think. The door mechanism will need to be addressed and the trunk has been molested enough to maybe not be able to be returned to normal. The trunk line will at least need to be capped.

Not what you ultimately asked, but I’m not sure you want to go down your path.

Thanks so much for somebody finally replying! So I did more research and found out that it was very hard to even get an aftermarket alarm on this car due to the vacuum pump in the wiring diagram to the car. I actually pulled my PSE pump from the trunk today took it all apart and found out that there was water intrusion inside which looks like shorted everything, inside it smells like something was burned! I'm going to be getting a remanufactured pump on eBay and installing the new one. I will be taking advice and plugging the yellow nylon tubing to the trunk as the trunk has been converted to Springs so the pump doesn't even actually work for the trunk. I'm guessing it got disconnected at one point. However yes you are right about the door I definitely need to take a look at that line and get that fixed. And I know that's definitely a big project. Anyways I do appreciate the feedback and it looks like I will be going the opposite way that I wanted to you because in the long run it will be cheaper.

I did get told since it is a used PSE pump that it would not have to be reprogrammed to my car and I would only need to reprogram if it was a brand new pump because of the memory loss? Do you know anything about that?

I must have gotten lucky with the version number (or, whatever) on my new pump as it was plug-and-play out of the box.

I doubt the door issue is a cracked line - but, a cracked vacuum chamber cap. Replacing the door mechanism is, indeed, a fairly big job. But, be patient and careful - hopefully with a helper - and it'll get done. There's a good thread on here somewhere (maybe a sticky) that I used to follow. There are kits on eBay for the just the vacuum cap. But, I found it difficult to remove/replace without breaking a tab. So, I just replaced the entire unit.

The PSE is a plug-in play system, but sometimes you will need to get it programmed to the car. This is just what I have been told I have no experience with it on my end. When I get my remanufactured one from eBay I'm going to just install it as it was previously and hope everything works. And yes you're right about the driver side door about the vacuum cap that's what I meant is not a crack in the line like the trunk.

get a pump from the same car that you own, preferrably with the same options outfitted from the manufacturer

if you have access to the Star mercedes diagnostic systems, you will copy the settings from your old pump in DAS, then you can "paste" these settings to the new pump once you plug it in. we call it a "teach-in" process. this process helps because if you do not address the missing systems from your car, the pump can run into overtime, overheat and subsequently fail

as far as the rear shade,this is not controlled by the vacuum system

Regarding the door locks, they are vacuum controlled so i assume an aftermarket lock set will be quite difficult to retrofit...i would expect it to cause unwanted issues with reliability and such