Installing 997 Adaptive Sports Seats in My 986

[KevinH1990]

https://www.planet-9.com/threads/987-2-base-seat-to-14-way-memory-seat-conversion.255990/

I have attached a pdf to post #12 of the thread I linked above showing how I used the information in the thread to install 997 adaptive sports seats in my 986 Boxster. Unfortunately, it appears that the file is too large to upload to this forum. These seats are heated and include powered lumbar supports and inflatable seat bottom and seat back bolsters. At this time, I have achieved the following:
1. Fully operational passenger seat - all motors, lumbar supports, side bolsters and seat heaters are working.
2. Driver's seat with operational seat motors and seat heaters.

The issues that I need to resolve involve the lumbar supports and the side bolsters in the driver’s seat. When I press the switches for the lumbar, the pump operates, and the lower lumbar reservoir inflates. Unfortunately, the upper lumbar reservoir does not inflate, nor will the lower lumbar deflate. When I press the buttons to inflate the side bolsters, I can hear the pump running, but the bolsters don't inflate.

I'm wondering whether there is an issue with either the wiring or one of the valve blocks that distribute air to the various components. (I have attached a wiring diagram of the seat showing the various components.) I discuss the possible issue in the following paragraphs.

Valve Blocks - It appears that I have two valve blocks in my seats. One is in the seat bottom, and I think the other is in the seat back. If someone knows how to access the valve block in the seat back without removing significant portions of the upholstery, I would appreciate guidance. If I can access the valve block in the seat back, I may be able to determine whether it is defective.

Wiring - As shown in the accompanying write up, the seat motor wiring is straightforward. I’ve been able to make all of the seat motors operate correctly, so I will focus on the problem with the lumbar and side bolster wiring. The wiring for the lumbar pump on the replacement harness consists of 6 wires with the following colors:

Green/Black
Black/Pink
Yellow/Green
Yellow/Black
Yellow/Blue
Blue/Brown

I found a matching wire color on the green 18-pin plug that attached to the seat memory module for each of the wires with one exception. Instead of Blue/Brown wire I have a Blue/White wire. When I matched and connected the wires on the new harness to the corresponding wiring already present in the seat, the pump motors operated when I pressed the lumbar control at the 12 o’clock, 3 o’clock and 6 o’clock position. This is how the passenger seat operates. When I press the 9 o’clock position on the passenger seat lumbar control, the lumbar deflates. Pressing the lumbar control at the 9 o’clock position on the driver’s seat does nothing.

The wiring for the side bolsters seems fairly simple. The original wiring that attached to the control module in my driver seat included two sets of brown and red wires. One set was attached to pins 10 and 11 and the others to pins 17 and 18 on the green plug. When I attached power and ground to these wires, the pump motors operated when I pressed the bolster inflation controls. However, the bolsters did not inflate. This suggests that the valve blocks are not allowing the air from the pump to travel to the correct reservoirs.

Another area I am exploring is that I had two wires on the green plug that don’t attach to the new harness these are the White wire on pin 1 and the Violet wire on pin 2. According to wiring diagram, these control the “Lo Back” and “Lo Forward” function on one of the valve blocks.

I will appreciate any suggestions that help me resolve the remaining issues with my driver's seat.

If anyone can provide a copy of the wiring diagram for the passenger seat that corresponds to the drivers-seat diagram I posted that will be helpful.

[KevinH1990]

I finally have all the functions in my driver and passenger seats working. This includes the seat motors, lumbar support, inflatable side bolsters and heat. Because the pdf with details is too large to include on this forum, I posted updated instructions on this Planet9 thread.:
https://www.planet-9.com/threads/987-2-base-seat-to-14-way-memory-seat-conversion.255990/

I discovered that there is a minor wiring difference between the 997 adaptive sports seats and the non-sport memory seats. There was also a problem specific to my driver's seat that occurred when I had an upholstery shop replace the lumbar pump motor. The shop installed the motor in a way that pressed on the air supply line to the side bolsters.

The reason I installed adaptive sports seats was to improve the support for cornering on the track. When I participated in a high-performance driver education event with the stock 986 seats, I found that I was sliding during turns. I tested the seats at an HPDE on Friday and Saturday. The adaptive sports seats solved this problem.

My 986 seats had memory and I'm considering whether I should attempt to add memory to the 997 seats. The 997 memory uses the CAN bus in that is not included in the 986. I think I have a way to work around that. If I decide to proceed with installing the memory, I will post an update.

[997_986]

Thank you very much. I can now also think about implementing this ;-)

[KevinH1990]

https://911uk.com/porsche/987-997-comfort-can-help-needed-for-987-memory-seat-install-in-a-986.128417/

I recommend that you consider this option as well. It wasn't available when I started my project. I would have used it if it had been. It appears to be a more elegant solution that requires less modification to the seat. Because you wouldn't need to buy a seat switch or a wiring harness, I expect that it would be less expensive.