Cayenne955TT

I did not do the repairs myself, but the system was confirmed to have no vacuum leaks after the repairs. The sensor also reads correctly per the ECU. The vacuum pump itself was also replaced with new OEM.

-Will

blakecam

I just experienced the same brake booster warning light. My independent mechanic replaced the entire vacuum hose assembly running between the vacuum pump and the brake booster. It luckily solved the issue for me, but he said if the warning light returns I would have to replace the actual brake booster unit. You may have a failing brake booster.

Cayenne955TT

That is where I am at this point - The only other question that not many people seem to talk about is the travel sensor in the booster itself. It is available separately and seems easier to replace than the entire booster. My booster both hold vacuum over night and will also "charge up" if ran down manually to test the booster like any booster would be tested. It almost makes sense that the only other sensor involved, the travel sensor, is bad. Any thoughts/does anyone have experience with this?

-Will

Corvetteboy6988

Cayenne955TT, did you ever figure this out?
i had a code and replaced my vacuum pump, is stopped work and kept blowing fuse #13 under the hood. With that solved, Im still having some drivability issues, rough, surging, etc. I've checked from the vac pump line and the line to the intake, and both hold vacuum, which should theoretically be all the way back to the booster. Not convinced yet it isnt the booster itself that is bad.
Im also thinking the vacuum feed line that goes tothe Ypipe and back of the manifold and supplies vacuum to the brake circuit might have a bad one way valve.

But was most curious if your issue was the booster, and how you checked it.