Mine arrived yesterday

 

Do they sell single seats, or do you need to buy both? And am I correct that the driver side is more plug and play than passenger? And also, if I'm 6-5 would the folding bucket not be low enough? Say even with the Cantrell or BBI mounts?

 

How I Installed 991 Euro Spec Folding Sport Bucket Seats (P03) in a US Car

!!! WARNING and Disclaimer !!!
This is not a guide, it’s just documentation of what I did, and I am NOT recommending you follow suit. Much of what is detailed below is tricking the car’s air bag system into thinking these seats are compliant. Any tampering with the car’s air bag system will put yourself and your passengers at risk. I do not take any responsibility for what you do with the information detailed in this post/thread, this information is offered for you to use or not use at your sole discretion and understanding of the serious risks involved.

When I installed these seats I quickly found out that neither seat is plug-n-play, and that I got an airbag light on my dash after installing the seats.



These are the options I had:

1. Live with the airbag light always on (and potential risks associated with that).
2. Have my car coded to remove/fix the airbag light. (A few places, like BGB Motorsports, have been able to do this)
3. Remove parts from my original US seats and retrofit them to the Sport bucket seats. (Least expensive solution)
4. Buy the necessary parts and install them on my new Sport bucket seats.

The details below show how I went about option #4 to eliminate the airbag light by "satisfying" all the car’s requirements (i.e. tricking), as well as how I retained the seat heating functionality on the Sport bucket seats.

Error Codes

These are the error codes I got when I installed the Sport bucket seats without any modifications.

Driver’s Side:

• 002804 - Seat position sensor driver 5%, open circuit

Passenger Side:

• 002B04 - Seat position sensor passenger 5%, open circuit
• 002104 - Front passenger buckle, open circuit
• 00611F - Seat occupancy detection, open circuit

Parts

Here are all the parts I bought to solve these error codes. I tried not to remove anything from my original seats (except one thing because I wasn’t sure if a new part would work without coding).

Ordered from the Dealer:

• (1) 991.622.784.01 - Passenger Seat Wiring Harness. This is the simplest harness I could find with all the connections I needed for the passenger side. It’s from a 991.2 GT3 with 4WSS+ w/ seat heating. However, I did need to modify this harness to use the correct connector for the seating heating on the sport bucket seat.
• (1) 991.803.184.07 - Passenger Seat Belt Buckle.
• (2) 9P1.980.341 - Seat position sensor. Need one for each side (driver seat and passenger seat). This actually isn’t the correct part number for a 991, because the dealer was having trouble figuring out the right part number. It’s for some other car in Porsche’s lineup (Cayenne?), but it worked well enough (even though it looks very different).
• (1) 9P1.971.391.C - Driver Seat Wiring Harness. This was a sacrificial part for me. I used it to pull some pin/wires from to make my seat position connection on the driver’s side sport bucket seat. And I used it to pull a seat heating connector off of, so I could splice it on to the passenger side harness I bought (which had the wrong type of seat heating connector).

Found on eBay:

• (1) Passenger Occupant Sensor Pad. There isn’t a good way to buy just this part from the dealer. It’s sold as a matched set with the sensor module, sensor pad, and seat cushion, which are all calibrated together (see service manual warning below). Also, this matched set is very expensive (I’ve heard something like $2500?). When searching eBay, any Porsche/Audi/VW pad ~should~ work as long as it has the right connector (typically from around 2012 to 2017 model year vehicles)
• (1) Male Seat Belt Buckle Clasp. Bought this to leave permanently installed in my new Passenger Seat Belt Buckle.

Reused from Original Passenger Seat:

• (1) 970.618.245.03 - Passenger Occupant Sensor Module. I’ve heard this part is coded to the car, and I couldn’t find one on eBay for cheap enough to test out that theory, so I just removed it from my original passenger seat (which was very easy to do).

Here's a warning from the Service Manual about replacing the Occupant Sensor.


Here's one example of an Occupant Sensor Pad that can be found on eBay. They can be found in several different shapes. This particular one from a Porsche Cayenne ended up fitting very well.


Most important thing to pay attention to when I was shopping for one of these Occupant Sensor Pads on eBay is that the black connector (pictured above) has a 3-pin layout (pictured below).


Here's a picture that shows the difference between the original 991 Seat Position Sensor, which I couldn't find the part number for, and the Seat Position Sensor I ended up purchasing for this project (which ended up working out fine).



Solving the Airbag Light on the Driver Side Sport Bucket Seat

Overview of Steps:

1. Add Pins for Seat Position Sensor to the main connector of the existing bucket harness
2. Connect Seat Position Sensor

First I started out by un-taping part of the new Driver Seat Wiring Harness I purchased. I wanted to harvest two things from this harness. The Seat Position Sensor Connector and pins, and the Wide 4-pin Seat Heating Connector (to be used later...)

This was relatively easy to un-tape. I also think I could have removed the Seat Position Sensor Connector and pins from my original driver's seat harness (if I didn't want to buy this extra harness), without being destructive to the harness.


Here's what the Seat Position Sensor Connector and pins looks like once removed from the main harness connector.


Then I simply wired that connector I just removed to the Driver's Seat Harness that comes with the Bucket Seat. Here's the pin layout:


Here's what the main harness connector will looked like once I was done. Also note that each of those pin blocks within the yellow connector (the grey, grey, and black pin blocks) easily slide out; the yellow plastic is just a shell holding all those blocks together.


Here's the completed underside of the Driver's Side Bucket



Solving the Airbag Light on the Passenger Side Sport Bucket Seat

Overview of Steps:

1. Install new Passenger Seat Wiring Harness
2. Reuse Thorax connector from existing bucket harness
3. Install and Connect the new Seat Belt Buckle
4. Connect Seat Position Sensor
5. Connect Passenger Occupant Sensor Module
6. Connect Passenger Occupant Sensor Mat

Once I did all these steps, this is what the completed underside of the Passenger Side Bucket looked like:










Fixing the Seat Heating on the Passenger Side Sport Bucket Seat

Overview of Steps:

1. Splice the seat heating connector from new Passenger Seat Wiring Harness to correct seat heating connector needed by existing bucket harness

The new Passenger Seat Wiring Harness that I bought doesn't have the right 4-pin Seat Heating Connector needed by the Passenger Side Bucket Seat. It does have all the seat heating pins and wires, but they are just going to the wrong type of connector. So I spliced those wires onto a connector that I harvested from the Drivers Seat Wiring Harness. I created a custom Molex connector to join the two halves.

The Passenger Seat Wiring Harness that I bought has this connector:


But I need a connector that looks like this, so I clipped this connector from the Drivers Seat Harness that I bought.


Then I followed this pin layout from the original Passenger Side Bucket's harness seat heating connector:


And created this custom seat heating adapter/connector:



Result

The seats look great, and no airbag light!






Bonus Parts

Plastic Trim Pieces. These go on the front of the slide rails. If I already had manual fore/aft adjusting seats, then I could have just reused all my existing trim. But with the fully electric seats, I could only reuse 2 of 4 of these trim pieces (plus I broke 2 of them, so I just bought a whole new set).

• 991-521-361-00 L
• 991-521-362-00 R
• 991-521-360-00 R
• 991-521-359-00 L

Lowering / Angle Adjustment Brackets:

• Cantrell: https://cantrellmotorsport.com/produ...side-mounts-2/
• Tarett: https://www.tarett.com/items/986-987...slb-detail.htm
• BBi (does it fit this seat?): https://www.bbiautosport.com/product...and-slider-kit

!!! WARNING and Disclaimer !!!
I repeat, this is not a guide, it’s just documentation of what I did, and I am NOT recommending you follow suit. Much of what is detailed above is tricking the car’s air bag system into thinking these seats are compliant. Any tampering with the car’s air bag system will put yourself and your passengers at risk. I do not take any responsibility for what you do with the information detailed in this post/thread, this information is offered for you to use or not use at your sole discretion and understanding of the serious risks involved.

 

^^ Excellent work and write-up marinb!

My plan for my GT4 is to use a race shop to code the airbags properly (as you describe, option #2) but I would love to get the occupancy sensor working as well. The problem that I see now is that all of the sensors require a pass-through hole for the wire. You are using the sub-belt pass through, but I intend on having harnesses on the passenger side to satisfy PCA HPDE rules. I can't see myself drilling a hole in these beautiful carbon seats for that so unless I can find a sensor pad that does not require that, I will probably skip it...

My other question is how the seat position sensor works. How does it determine seat position? It would seem like it needs to be mounted to the seat rails. Or are you simply plugging it in to get the airbag light to turn off?

 

Thanks!

You could drill a hole. It wouldn't be that bad (maybe silver dollar sized). I considered it, but ultimately did it this way since I wasn't running a harness on that seat.

They don't "work" in this setup. But that's fine. Typically (as far as I can tell), it senses when the seat is too far forward (like literally almost all the way forward). Since I am average height, this won't ever be the case.

This picture doesn't really help, but you'll see when you pull out your original seats. There is a magnet near the front of one of the rails, and when the sensor passes next to it then it triggers.

 

Another option for the sensor pad, is it could probably be rolled up and zip tied, so that it's always in a compressed state. Then place it under the seat. Then the passenger airbag would always be on. (again, this is serious tampering with the air bag system, so I'm not recommending this approach)

 

Great write up-any measurements on how much each seat weighs?

 

They were like half of what my 18-way seats with heating/cooling weighed. I don't remember exactly, but it was around ~35 lbs for each bucket seat.

 

Thanks! I am trying to determine if they are much lighter than the factory 4 way seats. I LOVE the look of these seats-would just like to justify a few pounds of weight savings as well.

 

FWIW, according to my internet research across multiple forums and threads the weights are:

18-Way: 61 lbs
4-Way: 51.6 lbs
LWB: 38 lbs
Sport Bucket: 35.6 lbs (aka GT2, folding bucket, Option P03)

 

Awesome info-thanks very much!!!

 

marinb, you deserve full hero status for your post above—thank you for sharing what you've learned!

A lot to digest here, but it's a treasure trove for those of us who want to make these seats work in a US car.

I like your approach of satisfying the car's systems rather than deleting safety features, which appeals to me over options 1-3. I also like your approach in avoiding a harvest of parts from the stock seats, keeping the two pairs of seats swappable. I wonder if there is an option 5—which is to not only satisfy them but to retain their full functionality. I suspect working seat position sensors might be figured out, but am at a loss on the occupancy sensor paired with the cushion unless 918 seat cushions can be swapped or re-contoured to fit? I don't even want to know what they go for...

Great to see a pic of your seatbelt buckle workaround—it's slicker than I would have thought from previous descriptions. I am curious to see if the US 918 bucket buckle I ordered might bypass the need for it, and will check back in on that. Your parts lists are super helpful, as well! The only thing that worries me a bit is the advent of smart airbags—which probably drive the factory warning you thoughtfully included. I suspect the occupancy sensor may be calibrated to work with a certain kind of foam thickness and density—which really underlines why a friend in the industry told me seats are like cars in being nearly or just as complex. I'd love to figure out the seat position sensors with full functionality, too, but it doesn't sound like any of this is easy.

I may have to pass on this upgrade, though I really don't want to. Driving the car back to back with the P03 bucket vs the 4WSS+, I am not sure the P03 offered that much more support—though I prefer its connectedness to the car, weight, aesthetics, rear-seat legroom, harness compatibility (if needed someday down the road), and then one more rather odd thing that may or may not pan out as a benefit, but a potentially important one to my family: smell. It's nothing that bothers me (I am largely smell deaf), but my better half started hating the smell of Porsche sports cars in the 987/997 era—a bummer for both of us, as she likes driving and riding in Porsches, and loved her first one, a 986. And then a RoW 987.2 Boxster Spyder showed up on a press loan and she noted "Hey, this one doesn't smell bad like the others." Back then, I wondered if it had something to do with US vs RoW spec interiors or smell packets, but have since learned that Porsche only recently hired a "smell engineer," well behind that trend in the industry. Which has me wondering if the folding buckets in that 987.2 Spyder were the thing that avoided the adhesive or foam (?) smell that bothers her. So I've been letting a pair of P03 seats marinate out of their boxes for a few weeks now, and they don't bother her olfactory senses one bit…

 

Thank you for this, also! Fwiw, I was both surprised and not surprised by the "feel" of 4WSS+ vs P03 buckets when pulling them out of the car. At first, I thought hmm, this isn't that different, and then I realized that walking any distance with each seat was very different because seats are awkward things to carry, and my back reminded me of the extra awkwardness of the 4WSS+ later that day. If I had to guess, I would have guessed 10-15 pounds, which matches up with your numbers above. So, ~30 pounds out of the car for two P03s vs 4WSS+, and ~50 pounds out of a car with 18W seats.

 

What a sick write up marinb. Not to mention the actual problem solving. This is rennlist gold. Impressive stuff. Thank you. I want to get these seats in my car badly.

 

This forum is a real treasure for Porsche enthusiasts.
marinb your post and knowledge transfer is very helpful.

As i am based in EU i have the folding backets to my car and based on this thread i feel quite Lucky that i spec then during my build.

Allow me to ask one question for your seat harness setup. If any member is aware feel free to help me understand.
Harness needs Hans.
Hans needs full roll Bar.
Harness with Harness Bar is not safe comparing to OEM 3 Belt Solution.

You have opened a topic Last year and finally you decided to proceed with your current setup.

Can you please elaborate further?
Do you plan to install a rollbar from BBI or other suplier as next step?