# Bug: Brake hold stopped working



## ummgood (Feb 13, 2017)

So this weekend I was in a very hilly town for my daughter's softball tournament and I was waiting at a light with a slight incline and I realized my car was rolling backwards and I stopped before I hit the car behind me. I am used to pressing hard at ever light and taking my foot off the brake. I really am so used to it I don't verify anymore (probably to my fault) that the brake hold is on. Anyway for the rest of the drive my car would not go into brake hold. I had to drive a few miles and at every light I tried to get it to engage. Some stops were on level ground and some were on an incline. I also tried restarting the car at a light and also putting it in park with no benefit. When I pulled into my destination I put the car in park and did a brake pedal two finger reset and left the car. When I returned everything was normal.

This was pretty annoying in this location because my car was constantly rolling backwards on hills when the light would turn green. I probably could have turned on creep but I am not used to having it on. I would have turned it on if the problem persisted. I had to do the old fashioned two foot start at lights like with my old 65 Mustang when it would stall occasionally. Anyone have this issue? This is a first for me after almost 12k miles. I am on 2018.49.20.


----------



## GDN (Oct 30, 2017)

This has nothing to do with the bug and I'm glad that a reboot helped, but here is a link to the Bosch iBooster. I'm fairly certain from a past article (which I can't find now) and from Google, this is used in the Model 3. If nothing else it is in an interesting read on current brakes and how they are integrated. https://www.bosch-mobility-solution...riving-safety-systems/brake-booster/ibooster/

EDIT - found the reference and likely one of the best sources - right here from @Ingineer - https://teslaownersonline.com/threads/amazing-inginineerix-model-3-teardown.6078/post-134437


----------



## Golden Gate (May 8, 2018)

Happened to me and a hard reset fixed it.


----------



## StarryNight (Nov 5, 2018)

Today I had the same issue. Out of the blue my Hill Hold stopped working in my Model 3. Two finger and brake restart did not fix. Flipping creep on and off also did not fix. What to do?

I feel it's dangerous without Hill Hold. I'm so used to it.


----------



## GDN (Oct 30, 2017)

StarryNight said:


> Today I had the same issue. Out of the blue my Hill Hold stopped working in my Model 3. Two finger and brake restart did not fix. Flipping creep on and off also did not fix. What to do?
> 
> I feel it's dangerous without Hill Hold. I'm so used to it.


Did it ever come back?


----------

