The trunk of my 09 SL550 will not close using the fob or the button on the trunk lid. It opens properly using the FOB or the lever on the door panel. Soft closure works if I close trunk manually (I sealed all the ports on the trunk mechanism). With trunk open and I push the button on the FOB, I can hear the trunk mechanism doing something. I get nothing if I push the button on the trunk lid. Anyone have this issue and the fix?
thanks

 

Hello, did you ever resolve this issue as I have exactly the same problem?

Thanks,

Jim.

 

Hi Jim. I ended up selling the car last year and never got it fixed before selling. Didn’t seem to bother the buyers and have no idea of whether or not they had it repaired. I was a little surprised that I didn’t get a good response on this forum. Good luck dave

 

Hello Dave, thanks for getting back to me. I troubleshot the issue and I lucked out. I found the trunk lid closure pump relay located at the end of the pump had failed. There are two relays and they are the same P/N. I swapped the two and the trunk lid would now power close, but not power open. MB wanted $49 for the relay. I purchased two relays online for $22, replaced both and trunk lid operation is now normal.
All the Best,
Jim.

 

Hi Jim, how did you know it was a relay issue? How did test your relay please?

A few weeks ago the soft close of my r230 SL 500 2004 stopped working. Just the day before it stoped working I noticed some random noise coming from the PSE pump and the boot light was flashing randomly. (See video).


The 20 amp yellow fuse behind the seat is intact. I understand it might be a leak in the system and the pump shut itself off but I wonder if have a relay issue as in yours. I appreciate if you could tell me how you diagnosed your relay issue. Thank you

 

Hello glasgow2,

Does your trunk power close (hydraulic) to the latch, but just won't latch (pneumatic), or the trunk won't power close which was my issue. The soft close (latch) function worked normally, I just had to manually pull the trunk lid down until it met the latch and then it would latch (soft close) normally on the pneumatic system.

I subscribe to alldata.com for all my vehicle manuals. I have only owned my SL for a couple of weeks, but I added the SL manual to my library shortly after taking delivery of the car. From my perspective, I find their manuals to be quite helpful.

I determined that the trunk lid would not close using the driver door switch, Smartkey or the switch on the trunk lid.
The trunk lid red close & lock switch lights were operational. However, the red indicator light on the driver door switch was extinguished.
When I pressed any one of these switched, I could hear the hydraulic distribution module cycle which was a good sign, but the pump would not run.
The trunk would open normally and the trunk lid pull down/soft close worked normally.
I checked and found no hydraulic leaks.
I checked fuses and electrical connections to the trunk lid actuator position switch.
I figured I had to determine why the pump would not close.
There are two relays mounted on the pump mount assy, one at each end. In my case they are both yellow color and P/N 002 542 14 19.
Again both relays are the same P/N.
I figured one relay operated the trunk close function and the other the open function.
I swapped the relays and when I pressed the close switch on the trunk lid, the trunk would now close, however, it would no longer open hydraulically
and the pump would not run, so basically, I had swapped the issue from the close to the open.
I checked with MB and they wanted $49 for the relay. I checked online and bought two (2) new relays from Amazon for $22.
I replaced both relays as precautionary and knowing the car is 12 years old.

I'm not sure if this helps, but good luck with your troubleshooting and repair.

Jim.

 

Hello glasgow2,

Does your trunk power close (hydraulic) to the latch, but just won't latch (pneumatic), or the trunk won't power close which was my issue. The soft close (latch) function worked normally, I just had to manually pull the trunk lid down until it met the latch and then it would latch (soft close) normally on the pneumatic system.

I subscribe to alldata.com for all my vehicle manuals. I have only owned my SL for a couple of weeks, but I added the SL manual to my library shortly after taking delivery of the car. From my perspective, I find their manuals to be quite helpful.

I determined that the trunk lid would not close using the driver door switch, Smartkey or the switch on the trunk lid.
The trunk lid red close & lock switch lights were operational. However, the red indicator light on the driver door switch was extinguished.
When I pressed any one of these switched, I could hear the hydraulic distribution module cycle which was a good sign, but the pump would not run.
The trunk would open normally and the trunk lid pull down/soft close worked normally.
I checked and found no hydraulic leaks.
I checked fuses and electrical connections to the trunk lid actuator position switch.
I figured I had to determine why the pump would not close.
There are two relays mounted on the pump mount assy, one at each end. In my case they are both yellow color and P/N 002 542 14 19.
Again both relays are the same P/N.
I figured one relay operated the trunk close function and the other the open function.
I swapped the relays and when I pressed the close switch on the trunk lid, the trunk would now close, however, it would no longer open hydraulically
and the pump would not run, so basically, I had swapped the issue from the close to the open.
I checked with MB and they wanted $49 for the relay. I checked online and bought two (2) new relays from Amazon for $22.
I replaced both relays as precautionary and knowing the car is 12 years old.

I'm not sure if this helps, but good luck with your troubleshooting and repair.

Jim.

 

Sorry for the delayed reply. In fact mine just sorted itself without me doing anything. Strange cars but lovely 🙂