SL/R231: Trunk Partition Retrofit
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Joined: Jun 2004
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Trunk Partition Retrofit
I'm reinstalling my SmartTop module (had to pull it while the dealer diagnosed a problem with the Keyless Entry constantly failing) and as I was removing the trunk panels I was curious if anyone has retrofit the new style automatic trunk partition into a Pre-Facelift R231? Is its possible? While I recognize that its not a huge issue, forgetting to close it does put damper on my "smooth getaways" some days 
Thread Starter
Junior Member
Joined: Jun 2004
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As you guessed, I removed the module mostly to ensure the techs didn't blame the issue there and not address the issue....but also to do some diagnosing of the problem myself. Basically about once a week my Keyless Go would not unlock or start the car. I thought perhaps it was a flat battery as charging it would always correct it, however I later realized that leaving it for 30 minutes would also correct it. In the end the dealer found that it was a software issue, updated the firmware on the computer for the keyless go and it has not happened since.
Pulling the module doesn't take that long so just decided to play it safe. I usually pulled it on my SLK every time I took it in but that was much easier to pull as it was basically just hidden under the carpet in the drivers side door sill.
Pulling the module doesn't take that long so just decided to play it safe. I usually pulled it on my SLK every time I took it in but that was much easier to pull as it was basically just hidden under the carpet in the drivers side door sill.
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Joined: Dec 2018
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R231 SL
I looked into this at length a while ago. I had a full parts list drawn up, but unfortunately I do not seem to be able to find it or my detailed notes at all.
From memory, the conclusions were as follows:
The principal parts, both the major cover and minor attachment parts and panels, were all of relatively low cost and simple to install, at around ~$/€/£ 500??. However, the cover itself is connected via wires to the Rear SAM (Signal Acquisition Module). This is different between the pre & post facelift models, and as such, this would have to be changed at ~$/€/£ 400??. The old module has no connector for the wires to a moving cover.
The big catch is that the new module would probably not be able to be correctly be programmed to the car - SCN coding would fail. I believe that the only way to successfully execute it would be to find another post-facelift R231 with the exact same set of options that connect to the Rear SAM, and borrow it to install the Rear SAM temporarily and SCN code it correctly to that car. The only alternative would be to attempt to change the car's model year code on VeDOK and I cannot imagine you would find anyone with sufficient access clearance who would be willing to do it, even temporarily. There is no option code associated with the different Rear SAM versions.
From memory, the conclusions were as follows:
The principal parts, both the major cover and minor attachment parts and panels, were all of relatively low cost and simple to install, at around ~$/€/£ 500??. However, the cover itself is connected via wires to the Rear SAM (Signal Acquisition Module). This is different between the pre & post facelift models, and as such, this would have to be changed at ~$/€/£ 400??. The old module has no connector for the wires to a moving cover.
The big catch is that the new module would probably not be able to be correctly be programmed to the car - SCN coding would fail. I believe that the only way to successfully execute it would be to find another post-facelift R231 with the exact same set of options that connect to the Rear SAM, and borrow it to install the Rear SAM temporarily and SCN code it correctly to that car. The only alternative would be to attempt to change the car's model year code on VeDOK and I cannot imagine you would find anyone with sufficient access clearance who would be willing to do it, even temporarily. There is no option code associated with the different Rear SAM versions.
Last edited by D49; Aug 11, 2019 at 10:07 PM.
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Joined: Jun 2004
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Thanks. Not the answer I wanted to hear but sounds like pretty a well researched answer for sure. Perhaps I will give it some thought and see if there is a less invasive way to solve this. I wonder if the cover could be controlled via some other controller(CAN) or direct IO....I'm not too afraid of a bit of hacking so may be fun to look into as a project some weekend.
