I understand this is a warranty repair in the states? Here in NZ I think it would be unlikely although I didnt bother to ring and ask benz (this w222 s550 Is a jap import) as theres no dealer in my town so I decided to pull it apart to see if I could figure out what actually goes wrong with them... that was kinda a fail as you'll see below although I think I got the jist of whats going on. (the white microswitch at the top of the second photo is the suspect area as thats where the latch strikes by another mechanism off that gear onto the microswitch (their is a fair bit going on in there). Something is deff failing/not working in that area on these as thats why the trunk up down buttons dont light up and dont work.

Here's some pics of the internals of the boot latch:







It basically was very hard to pull apart and keep track of where everything goes so this one is pretty much toast and im just going to buy a new one. (Does anyone know the part number for this latch off hand?)

So I dont think I can put this together again and I cant even figure out what was quite wrong with it. I notice when I plug it back into the car and push both micro switches my boot close button lights up whereas I couldnt get it to before because the latch was in the open position but wouldnt lock itself on the catch so I believe one of the springs internal with the piece that locks the catch after its latched isnt working but as I said I couldnt see anything obvious wrong with and in the process of dismantling this I think iv damaged it beyond repair (drilled out the rivets and hit it bit hard with a punch to try drive out the rivets which I think has misaligned them slightly as its just bent the outer casing so the latch isnt as smooth as it was before dissassembly again I believe a spring or something was to weak to push the lock finger in behind the latch when its in the down position or seized due to a weak spring). So for anyone in the future dont try to drive out the rivets just drill them out from the plastic side until the plastic becomes loose and you can remove the plastic cover.

So yeah I had a go at DIYing this but I think I stuffed up when dismantling it.

So I have read MB has updated this latch as they were failing all over the show on these cars??

I dont know much about it really and not much info around about them that I can see.


Basically id just like to order a new latch mechanism from somewhere other than benz..... Can anyone point me in the right direction?

 

Is A2317500085 the latest part number?

 

Hello Austingtir,

I had a similar issue with my W221, even appears the lock is the same construction! What I deduced was that it was a sticky or bad microswitch. As a result I removed the motor attached and used electrical contact cleaner in the area of the microswitch. So far I haven't had much issue, unless their is a rapid temperature drop! Also lubricating with silicone spray has helped as well.

To find the latest part number ring up an MB dealer, give them the last 8 of your VIN and request cost and part number for the trunk latch. Lastly, if you find any information about a recall or warranty repair surrounding this latch drop it here. I would love to not eventually pay $400-500 for a latch assembly!

 

I had another look at this one and nearly got it back together I just cant figure out the position of one spring in there. Anyway I bought a new one off aliexpress for $160NZD (same part number as this one).

So yeah they are cheap on there I have no doubt these things are originally made in china anyways so im prepared to take the chance on this aliexpress one.