Newly acquired 2006 S65 and the dynamic seats and pulse massage do not work in the front. The back seat lumbar works fine (different circuit i guess). Isolated problem to leaking line under driver seat. Pulled and checked pump in the trunk and it is working fine. I can hear air hissing under the seat and the noise gets louder when I lift the carpet. Unfortunately I believe the problem to be under the driver seat under the carpet where I can't get to it. So in the meantime, I pulled the leaky line from the reservoir and plugged that port on the reservior so it now pressurizes the rest of the system and doesn't make the pump run excessively.

Do I have to take the driver seat off to get under there? If so, how hard is that to do? Not sure what I'll find under there, but expect it to just be busted line or connector.

Helpful hint to anyone looking for leaks......You can pressurize the system with an air compressor (set regulator to just 2-5 psi). I just hooked a rubber hose from the nipple on the reservoir where the pump feeds in and then used a little adapter on the compressor to go in the other end of the hose. This blew air into the system and let me find the leak under the driver seat. Just can't see how to get to the leak to fix it.

Any help is appreciated.

Just update on this. There are 2 lines off the interactive reservoir in the driver side trunk. One goes to driver seat, and other to passenger seat. Both of these lines run in a conduit under the driver seat. The conduit is under the air conditioning duct (which is easy enough to remove). The passenger side line was broken under the driver seat. It runs in a conduit with a bunch of wires. I couldn't see what caused the break in the line, but these lines look like they deteriorate and get brittle. Anyhow. I just broke the line completely into where it was cracked and then rejoined the line with a rubber hose that slipped over the factory lines and used a little silicone to hold it (was a tight press fit). Seat did not have to come out of car but would've made access easier. I just loosened the 4 bolts holding the seat and tilted the seat up. Disconnected air line and electrical connector but didn't have to removed the little cable that is hooked to the seat. Took a couple hours to do the job, but now the wife has massage in her seat

Now to get new tires.....

Awesome write up!! If you can take some pics with your phone and post them next time-we can document these repairs to help others too