I swear seats and air lines are the bane of my existence lately. Fix one leak in the backseat, then I end up moving the front passenger seat and that cracks another line, fix that, yee haw here we are now.

So the driver's seat won't inflate the side lateral and leg lateral on the right side. Who knows how long it has been going on, because the seats always seem to be in some la-la land with something going on so I'm digging more into it.

Couple things...
1) I can't hear air leaks anywhere. When I try to inflate them, one side inflates and stays inflated. There is no hissing or anything when inflating from the other side.
2) Watching the pump on DAS, it will cycle on and off. It hits around 2000 hpa, cycles off. Drops to 1300, cycles on. This is when doing nothing with the seats.
3) Leave the car alone for around an hour, pop the door and pump will cycle for about 10-15 seconds. I have no idea if this is normal, but I do know with a leak that baby will run until it cuts itself off which is probably around a minute.

Bad adapter with a faulty valve? VIN doesn't fall in the TSB for that yet I'm leaning towards that since it looks like single feed line into it. But just seems darn weird the seat cushion also has the same issue. But with this car, anything is possible.

 

I just repaired my leaking system. The safety valve in the air reservoir failed and I had to replace the whole tank as the valve is not available alone. I bet in Germany it is as the valve is a separate part easily removable in the reservoir tank..

In my car the air pump comes on for some 10-15 s each time I enter the car so this is normal.

For the poorly functioning side bladders I have the same issue but only on the seat. The seat back one works just fine. The one on right side of the seat still works but it is weak.

Im thinking it is a valve issue or the air tubing to the right side has some sort of restriction but this is not a big deal for me as I normally keep the seat part side bolsters at very low setting.

Your problem could be bad bladders as already suggested IF each side bladder has its own valve as it think they must have. If they didn’t neither side would hold air if one bladder leaks.

 

when the car sleeps after locking the seat's release some air to take the strain off, and builds it back when unlocking. If you turn it off and remove the key and sit in the car after 7 mins you can both hear the valve move, and the seats "relax"

for the OP, on older cars the flexi pipes do fracture (there's a good post about seat modules and common pipe fracture locations - with lots of pictures). Its about a year old. Also the modules seem to die, but some claim disconnect and remake multiplug connections helps just as much - they have about 30 wires to the module over 4 multiplugs. The warning about 240volts is OK if its been asleep before you start work

 

Yeah the bolsters have their own valves so in the 1/10,000 chance you have a fully functioning seat and its a full moon you can turn on dynamic mode and they individually inflate driving through the corners.

Not doubting having a bad air bladder. I just find it a tad wild it does absolutely nothing. Doesn't even try to inflate. No sound whatsoever. Would be a helluva tear on the seam or whatever. Looks like yanking it through the seat without taking a lot apart seems doable based on a youtube video.

I'll hook it up on DAS again and dig around more.

 

the pump can trip if its been working too hard on a thermal cut out... and it doesn't cut back in - it remains locked out
Mine came to life as I knelt on the seat cushions testing fuses in the rear SAM. I think it got the pressure high enough to wake up - before that I was stuck and the faults wouldn't clear out of the diagnostics

 

While working on my leaking reservoir my pump tripped out several times for over heating but it always started working again after it cooled down.

 

Service Campaign 2007080001 AUG07 Malfunctions may occur in the dynamic/multi-contour seat modules, which may result in inflation or deflation of the air cushions without cause. Dealers will update the control module software for the dynamic/multi-contour seats. Approximately 3,205 vehicles are affected.

 

Question. My drivers side inside bolster will inflate but instantly deflates. The active bolster function doesn't work except for the side that inflates and after a few times shuts off and then neither side of the seat works, only the massage function. On the passenger side the outer bolster doesn't stay inflated and since I don't have anyone to drive me the dynamic seat shows as working but I'm pretty sure it will do the exact same thing as the drivers side. I'm wondering if I can just buy one seat unit and replace the inner bladder on the drives side and the outer bladder on the passenger side. They aren't left and right but I'm wondering if I can take the hose fittings off without any trouble? Anyone done surgery like this before?

 

look for a recent pair of posts with links to the right post everyone should have found and continued to build upon - with more data photos on what usually fails