MB-Dude

The dynamic seats in my '05 S55 have stopped working. StarDiag shows code 9250 - Pressure Buildup Not Possible. Pump could be shot, or there is a leak somewhere. Haven't worked on the dynamic seats before, so I'm hoping someone has a basic (or detailed) layout/schematic of the pump-reservoir-valving-seats. I would prefer to not reinvent the wheel if a document or printed knowledge is already available. Thanks in advance.
Cheers,
Jeff

ibeforreal

Have you tried using startekinfo to see the layout of the seats?

MB-Dude

Good news is the DSP unit operates well - pressure where it should and vacuum where expected. After removing the telephone controller, I found 2 broken pressure tubes; the ones that feed the front seats. Looks like when the car was assembled, they didn;t put enough length for the pressure hose for strain relief, so they kinked and broke over time.


Made a couple temporary replacement hose sections from standard windshield washer hose about the same size. Using a couple male-to-male connectors, I was able to get the system to hold enough pressure to pass the DAS test procedure. This confirms I found the correct problem. But the rubber hose is not designed for this much pressure and they leak. So once I get to the nearest MB dealer (~40 miles away), I'll get some of the correct tubing and connectors, and make a more permanent repair.


Cheers,
Jeff

ibeforreal

Always great to hear good results.