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Old Jul 4, 2021 | 06:26 PM
  #1  
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Default Roll-over protection module

Does anyone know how to get past the plastic cover? I unscrewed the single screw on top but it still won’t budge. It appears to be on a pivot point but it won’t swivel open because the actual module case inside is blocking it. I’m kinda getting tired of breaking brittle plastic on this 20 year old car so I’m being careful. Appreciate your help



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Old Jul 8, 2021 | 01:06 PM
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Bumping this because I have a hard time believing no one has ever taken this off at some point.
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Old Jul 9, 2021 | 05:01 PM
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Yogi I've never messed with this part but since you're not getting any help I thought I'd try to sleuth a bit and see if I could find some answers for you. It's part #996-551-221-01. I found this picture of the bottom of it and it looks like it's just two plastic clips that grab onto a bolt or some section of the tunnel underneath it. I don't see any other mounting points - I saw the hole for the single screw you said you removed. If you search for that part number you'll see more photos of other angles, but this was the most revealing I could find of the underside. Can you reach in there and feel if there are bolts snugged up on either side? Otherwise it may be a prying situation.. If you break it - a new one is $38, so not terrible.



Last edited by Dr_Strangelove; Jul 9, 2021 at 05:09 PM. Reason: Picture wouldn't post.
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Old Jul 9, 2021 | 05:27 PM
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Originally Posted by Dr_Strangelove
Yogi I've never messed with this part but since you're not getting any help I thought I'd try to sleuth a bit and see if I could find some answers for you. It's part #996-551-221-01. I found this picture of the bottom of it and it looks like it's just two plastic clips that grab onto a bolt or some section of the tunnel underneath it. I don't see any other mounting points - I saw the hole for the single screw you said you removed. If you search for that part number you'll see more photos of other angles, but this was the most revealing I could find of the underside. Can you reach in there and feel if there are bolts snugged up on either side? Otherwise it may be a prying situation.. If you break it - a new one is $38, so not terrible.


Hay appreciate you jumping in. There’s very little lateral play on those pivot point. I got my hands on a replacement module and noticed that it must have been installed with bolts only Porsche can undo with a special tool because the mount points appear to have been cut. The shell won’t pivot because the module is huge and it bumping into it on top.



I think I’ll be dealing with another issue once I get the shell off with those bolts 😢

I’m going to get medieval on it here in a minute. 🪓🪚
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Old Jul 9, 2021 | 05:40 PM
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Yes that module is held in with shear-head bolts. You'll need to grind a screwdriver slot in the heads to unscrew them.
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Old Jul 9, 2021 | 06:04 PM
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Originally Posted by theprf
Yes that module is held in with shear-head bolts. You'll need to grind a screwdriver slot in the heads to unscrew them.
Thanks know how to open the cover?
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Old Jul 9, 2021 | 06:29 PM
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Pry the cover off with a trim tool, use one on both sides from the front under the foam tape. Next to the parking brake cables.
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Old Jul 15, 2021 | 02:00 PM
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@theprf thanks for the tip. It worked like a charm. So before I hack away at those proprietary bolts I decided to attach the new module to the car first. Same result. The ECU doesn't see the roll-over feature. My guess is it's not receiving power. I've traced most of the wiring back to the convertible top module for power but I believe the problem might be between the power source and the magnets that (I'm guessing here) sense a roll-over and trigger the loops to pop up. I've searched through pages of wiring diagrams and workshop manuals and can't seem to find the magnets. Are they inside the roll-over module itself? It would make sense but the diagram has them outside of the module.


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Old Jul 15, 2021 | 02:21 PM
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I believe the magnets are the end of stroke indication for the pop up rollbars. Or they may be the release for the pop up rollbars. I don't know for sure. They aren't in the rollover module as the schematic shows wire leading to them. The roll over protection module's powered from fuse E1, you might check that.
That module you have there, that's the "sensor overturn M439" I take it? It's certainly not the power top control unit, it does not have enough wires going to it. In that case you might check if you have power between pin #11 and pin#2 on the connector to rule out a wiring break.
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Old Jul 15, 2021 | 03:10 PM
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Originally Posted by theprf
I believe the magnets are the end of stroke indication for the pop up rollbars. Or they may be the release for the pop up rollbars. I don't know for sure. They aren't in the rollover module as the schematic shows wire leading to them. The roll over protection module's powered from fuse E1, you might check that.
That module you have there, that's the "sensor overturn M439" I take it? It's certainly not the power top control unit, it does not have enough wires going to it. In that case you might check if you have power between pin #11 and pin#2 on the connector to rule out a wiring break.
Yes, that's just the roll over module. The cabrio module is on the other end of that image M439. So if the magnets are part of the pop-up bars then it's not meant to detect the roll-over and trigger the event, right?
I'll check the fuse again.
I was able to get the module off the car w/o too much fuss. I used my Rocket Sockets to bite onto the bolt head. The was the only one that I had to use a heat gun to melt the threaded collar out of the unit.
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Old Jul 15, 2021 | 03:25 PM
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I believe the actual sensor is inside the roll over module itself, which is why it's located on the car's centerline and at it's center of gravity.
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Old Jul 15, 2021 | 04:25 PM
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Ok, I'm pretty green when it comes to reading wiring schematics but looking over it again it appears that it's getting power from the Orange wire. I tested for voltage on that wire and I'm getting a consistent 1.6 volts. That doesn't seem like a whole lot of power so I'm guessing either there's a resistance problem or this module uses very little electricity to function; which it's not doing at the moment. Neither module, new or old. Durametric states there's a communications error or the module doesn't exist.
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Old Jul 15, 2021 | 05:08 PM
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With the key on you should get battery voltage between the orange and the brown wire. Around 12.4 volts with the engine off, 13.6 or so with the engine running. You need to use a very fine probe on the meter, as the pins are buried fairly deeply in the plug.
If you don't get this, then check for voltage between the orange wire and the car body (ground, bare metal).
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Old Jul 15, 2021 | 07:00 PM
  #14  
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Originally Posted by theprf
With the key on you should get battery voltage between the orange and the brown wire. Around 12.4 volts with the engine off, 13.6 or so with the engine running. You need to use a very fine probe on the meter, as the pins are buried fairly deeply in the plug.
If you don't get this, then check for voltage between the orange wire and the car body (ground, bare metal).
1.6v orange and brown/frame engine off
1.8v engine on
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Old Jul 15, 2021 | 08:39 PM
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Neither module, new or old. Durametric states there's a communications error or the module doesn't exist.

Durametric had an issue awhile back reading the rollover module. I helped them fix this issue. Make sure you are using the latest software.
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