Brake booster without function

[XR116]

Since there are many members with a very good technical knowledge, I hope to have luck solving my issue...

I have a roadster 2.0 from 2009 since 1 year, about 55000km and it drives fine - no issues up to now.
My basic question is: Is the brake booster (power brake unit) controlled by the VMS?
I had to reset the VMS, because I was not able to get my logfiles. So I resetted the VMS by pulling the black and blue plug, reinserted them and was able to get my logfiles again. That worked fine.
After starting the car, I missed the noise from the brake booster and it was without function. After driving about 5min the function came back. I parked the car, went to a customer, started 45min later and booster without function...came back again a few minutes later, but the next day it did not came back and since then I have to step on the pedal really hard to get it stopped at traffic lights. Driving is possible as the regen does a lot of the work, but I would like to get the function back.
I am wondering if this is because I resetted the VMS, or if it is just a coincidence. I hope it is just a "cable-thing"...

Does someone has an idea?

I checked the following:
brake fluid is at the right level
fuse #22 is ok and I get 12,9Volt at the fuse socket when I turn the key to ON position

Thanks for your Help!

Dirk

 

[ML Auto]

Probably a bad pressure switch on the pump. It operates whenever the key is on, there is no other control. The switch cycles the pump, turning it on whenever there is low vacuum.

 

[dhrivnak]

I do not think there is any interaction with the VMS. So the pressure switch and possibly a bad wire is your issue.

 

[XR116]

Thanks or your reply!
I unmounted the left front tire and the plastic housing inside to dig for the pump of the booster, but it is not possible (for me) to get it out without removing the front bumper. So it put it all together again.
I was driving about 500km on Saturday and the fuction of the brake booster came back again...but not from the start, but after several minutes of driving. After turning the car off and on again (charging i.e.) it took the booster some minutes again to work. Somehow weird. Perhaps I have to take it to Tesla...

 

[XR116]

In the end, the booster is functioning well from the start...don't know why, tried to do something, but was not able to take the booster pump out (without removing the front bumper), but ... it is working. Perhaps some self healing capabilities of the roadster...

 

[X.l.r.8]

LOL I doubt any part is self healing, you probably moved something that was making a bad connection. if it happens again which in all probability it will, get ready to remove the bumper. sounds like a poor contact not allowing the pump to cycle so look straight to connections.