Seat swap questions - Sofas to carbon buckets
 

Hello all,

Although my car is a 2008 911 GT2 I suspect it will be the same issue for any 997.1 generation car making the switch. My car came equipped with the basic sport seats (sofas) which have electronic movement controls, seat memory, and heaters on them...with all corresponding factory buttons to match. Everything works normally as you'd expect of course. My goal is to install my newly reupholstered manual GT2 carbon bucket seats, but I have a few questions about the behavior that may be interpreted by my car when the original seats are no longer there.

1. Should all factory plugs work normally?
2. Should my carbon bucket seat airbags be fully functional?
3. Should I expect any CELs due to the swap alone?
4. After the swap, if a button is pressed which no longer serves any purpose (memory controls, seat heaters), do you suspect a CEL will result?

I am suspicious that the car will 'miss' it's OEM seats in it's current state of tune, and I further suspect that I may need to have a Durametric Pro or PIWIS visit to convince the car that it no longer has the seats that it does, but would love to know if that's the case.

Feel free to let me know I should have searched too, because I actually deserve it this time. :)

Thanks all!

Going from factory sofas, manual or full power to carbon buckets is fine. The issue is going from manual seats to full power.

You may get an airbag warning if there is some remaining power in the system. But most likely not if you disconnect the battery. If your seats have heat and you press a button, or you press a memory seat button, there won’t be an error light. You may have to go to your dealer though and have some things coded with a PIWIS. Expect to pay an hour of labor for this but it can be done after your seats are installed. No need to have it all done there.

Thanks for the quick reply. I am going to disconnect the negative battery terminal before I disconnect the actual connectors under the seats, but want to leave them hooked up so I can move the power seats fore and aft to access the actual bolts prior to removal.

I forgot one important thing regarding the seat-belts, as they mount differently for each application I think. Referencing my other Porsche (which has carbon buckets from the factory), I see that the belt is attached to the base of the seat itself, and I really hope I have that bolt. Is there anything unusual about that bolt that holds them to the side of the seat? I may be overlooking something but will know more soon. Thanks again as I'm excited to have proper carbon buckets in the GT2 and am about to start the work.

As I want my DRLs disabled (they were turned on for the car to live in Canada prior to my ownership), I have a feeling that a PIWIS visit is inevitable. :)

If you don’t have that bolt, you should have no problem ordering it from suncoast or your dealer. I can probably find the part number if you need it. I don’t think there is anything unusual about the bolt though.

What I have learned so far is that all my hardware appears to work, but when looking at my GT3 RS as reference, there are some differences too. The seat bolts that hold the seat to the floor appear to be physically smaller from the sport seats (head design) and there is a 'collar' of sorts that goes between the seat belt retention bolt and the seat frame that is thinner on the GT3 RS. However, all the bolts on the GT2 do work, they may just not be optimal for the carbon buckets overall. My biggest struggle is keeping the seat tracks on the carbon buckets at roughly the same length to install them. I had it close a couple of times but ran out of time before dinner. I will try again tonight.

Taking the harness off the sport seat was a bit harder than I expected too, but only because I had never done it and had to figure out that there was a slider which helped to hold it to the connector. Once you slide that piece, everything came apart nicely. It appears there will be an unused plug for the carbon buckets on the drivers side as a result of those seats being so much simpler. More to come...

I went to my local Porsche dealer today to see what the revised seat-belt and seat hardware cost and it was fairly clear I didn't need any of it after studying part numbers. Some of the confusion may be that I'm comparing what I'm putting in a 2008 GT2 with what I see on a 2010 GT3 RS (regarding the seats and associated hardware), meaning they may have revised some part numbers by 2010. But I'm OK with my 2008 spec project.

So the swap itself went fine, but I do have an airbag light on post swap. I was at a Porsche shop yesterday for a dyno day and they plugged in the Durametric Pro and saw that it was throwing airbag communication failure messages. They reset it twice, but the same messages did come back, so I'll have to look at these connectors again. It seems hard to believe that I hooked up anything incorrectly as there are a total of 2 connections per seat, but obviously something isn't quite right. I'll keep you guys updated when I resolve this in the future. Seats themselves are fantastic, and definitely the way a GT2 should be equipped!

That's definitely interesting. Airbag issues I have not heard of in the past so I am guessing it is just a connector or something, although it does seem difficult to believe that you would have connected it improperly. Keep us posted/informed of what you find.

I suppose anything is possible as I'm no Porsche mechanic, but I took my time and examined the connectors, which are not complicated. Another buddy seems to believe that the car does indeed need to be reprogrammed to know it has different seats than it was born with, although I know that is not the opinion shared by this board and the advice I received here. I'll ask a few more qualified people to see if that opinion is shared. I do kind of hope it is that as I feel these connectors are mostly fool-proof (but I've been known to be a fool before!). :)

One odd thing I did notice is that my power mirror memory setting still works, so although the seats are now manual I do need to update my power mirror setting to match the new seat configuration. Perhaps that is indeed somehow related, if only a bit?

Not sure when I'll resolve this, but I will strive to update the thread when I do for the benefit of others. For the weight weenies among us, total weight savings from the swap from sofa seats to carbon buckets was a quantified 51.5 pounds, only complicated a it by a Brey-Krause fire extinguisher bracket attached to the underside of the passenger sofa seat.

Hi ​​​@Steve Theodore did you ever get your carbon bucket swap to work? I'm going to attempt to do the same thing. I'd be grateful for any help. Thank you!

Yes sir, and it took a PIWIS 3 to code it out so that the car no longer thought it had adaptive sport seats. I do think the 'real' problem was with my seat belt receptacle for the record though, so they made the car think it didn't need that either. My SRS system is still working, but this is similar to what you'd do for coding on a car with harnesses. If I recall that was the issue more so than the seat swap itself, but it has been a couple of years. Regardless, the PIWIS and some re-coding is what I needed to resolve my specific issue. Good luck with yours!

@jreifler recently put carbon buckets in his 997.2 GT3 and also had no issues. His is extra slick as he got euro buckets that retained the heating function.

If you put in Euro-spec buckets you have to code out the airbag weight sensor (In PIWIS 3: Diagnostics → <Select Car> → POSIP → Coding programming (7) → AWS → Change to “no”). You shouldn't have to do anything for US-spec buckets that have a AWS on the bottom of the passenger seat.

As an aside. I was on carnewals site and it said 991 buckets no longer available

I'm going to be replacing my 7.2 adaptive sofas with my kevlar Profi Spas that came out of my 996. I assume the same PIWIS coding procedure for the OEM Euro buckets can be used when swapping in a non OEM seat?

We are essentially deactivating the seat airbag and the weight weight sensor, correct? This applies to both seats or does one need to specify driver and passenger side in PIWIS? Thx..