Charlie Wise

Given Im not particularly fussed about auto locking and boot etc and lumbar support in the short term ---- will my SL500 2002 operate ok without a PSE pump until I can afford to replace it I have heard it can cause problems with the roof down mechanism?

Robert Eccles

The PSE pump powers the trunk soft close mechanism. If that does not work, I don’t think your Vario roof will work. The PSE is a pretty simple device and can be easily repaired in many cases. The parts for the repair are readily available online and relatively inexpensive.

I hope this helps.

Rob

bobterry99

You heard right. What's more, the Easy Pack feature will not work.

Tony Ryan

Hi Bob , im a bit late to this thread but can you confirm for me , i have NO PSE pump - missing when i rescued the car , a bit like the OP i wasnt really fussed about it , but now with nothing but time on my hands i wouldnt mind getting my Roof to work ( 2002 SL55 AMG ) .
If the answer ,as i assume is NO it will not work at all , then is there a purely mechanical way of fooling/tricking it down , i have seen the emergency Roof UP video that shows various ways of getting the Trunk out of the way , wish i knew that before i stripped the boot carpets,lol . Is there also a way to put it Down ??

matk

I recently repaired my PSE pump and can confirm the roof will not operate as the boot will not fully close to fully locked. On mine I got repeated “boot unlocked” red warnings on the dash too.

However on opening the PSE pump up the problem on mine was only a shattered impeller and the repair was straightforward. You can get the PSE pump out and open for examination in about 30 mins maximum, so I’d highly recommend doing that to investigate. If it shows water ingress and corrosion that may not be so straightforward.

Tony Ryan

Thanks for the reply Mat, its a s i assumed then , sadly i have NO pse pump at all or id have it apart to see whats going on in there .
I would really like to see if theres a fully Mechanical "only " way of putting oit down too , im bored and fancy seeing it opened up , especially if i dont have to buy a pump to do it !
Anyone got a cheap one ??

bobterry99

If like me you really don't care about the pump pneumatic functions, Tony, then you can use a pump which is mechanically broken. Perhaps start a thread stating you are looking for such a pump.

The reason your roof does not work is because the trunk partition switch is wired to the PSE pump. Absent a pump, the roof controller does not receive a signal that the partition is closed. And since the signal from the PSE comes over the CAN, there is no way to substitute for the pump.

Tony Ryan

Thats absolutley the concise answer i was after , thanks very much . So even if the pump has issues , as long as the signal is there it makes a circuit , i wonder what the market for dodgy pumps is like here in the UK ,lol

matk

But on mine when the pump was present but broken the roof would not work at all.

bobterry99

Here is an experiment. Open your trunk lid. Remove the manifold from the PSE pump to simulate a mechanically failed pump. Now slam the trunk lid closed. Does your roof operate? (It should.)
.

matk

I tried that many times and it didn’t work. No matter how hard I slammed the boot, it would always close and lock.......... but........... would never do the final “vacuum” seal and the roof would not open.

Im not disputing what you’re saying, just reporting what I experienced. As soon as I repaired the PSE pump everything restored to normality.

bobterry99

You closing the trunk lid and locking it arrives at the same result as you gently closing the lid and having the pump pull the lid down locked. The roof controller doesn't care how the lid got closed, nor can it tell.

Tony, at this point you may feel it is a risk to purchase a non-working pump. You can't do the experiment that I suggested which proves a pump needn't function mechanically. But there is another tell.

When you are driving do you get a message in the instrument cluster telling you to close the trunk lid? And is the little red LED on the trunk release switch lit? If neither case, then you know the roof controller is receiving a status that the trunk lid is completely closed, and you can have complete confidence that a broken pump can work. There is the caveat, though, that the pump must still function electrically, of course.

Tony Ryan

Thanks Bob , sadly the car isnt quite ready to be driven its in bits while i sort a number of other issues , but next time its running i will check the LED's for this information .
My Questions till stands tho , is there a purely mechanical way of putting the roof down , is it the reverse of the putting it up Video , slacken pump , undo the catches in the boot etc .

matk

Just to reiterate even when slamming the boot it would not latch as far down as when the pump pulled it. However your answer is making more sense to me now, my problem was impeller failure and as a result it was continuously blowing the fuse. Therefore although my pump was fully repairable, it was NOT electrically working. I also had the red light lit on the boot release switch in the door panel and I was getting boot not closed warning messages in the dash. So I understand when you say the pump can be broken but still working electrically, mine was not in that condition.