How does the whole "Auto Brake Feature" work?
Thread Starter
Senior Member
Joined: Nov 2016
Posts: 268
Likes: 35
From: Western Massachusetts
2019 S450 Silver w/ black interior
How does the whole "Auto Brake Feature" work?
I understand there are sensors that detect a pending collision and the car will brake itself, but how does the whole process work? Are the brakes electrically controlled? Does the brake pedal actually move when the car brakes for you? What happens when you realize what is happening and react by putting your foot on the brake pedal, does it feel weird? I assume the rear brake lights come on during this whole process.
Just curious since I never drove a car with this feature.
Just curious since I never drove a car with this feature.
Member
Joined: Nov 2016
Posts: 88
Likes: 13
From: Long Island, NY
2014 Mercedes Benz E350 Sport 4matic
The brakes, throttle, and steering are not mechanically connected they are all electronic. When the car auto brakes it will just slow to a stop, now if you put your foot on the pedal it will feel the same as normal, it does not move on its own and only has a short built in range into it to give the appearance of a firm well adjusted brake.
Takes a little getting used to, kind of like the steering, if you notice for example if you it bump on one side the car compensates for it and the steering wheel doesn't jerk around.
Takes a little getting used to, kind of like the steering, if you notice for example if you it bump on one side the car compensates for it and the steering wheel doesn't jerk around.
Thread Starter
Senior Member
Joined: Nov 2016
Posts: 268
Likes: 35
From: Western Massachusetts
2019 S450 Silver w/ black interior
Ah, ok that makes sense. So in the case of using Distronic I can see how the car will "trail" brake to maintain distance, but couldn't grab the concept of emergency braking. All the YouTube videos I watched only shows the car braking, nothing shows what the actual brake pedal does.
Senior Member
Joined: May 2015
Posts: 326
Likes: 3
2011 E550
The brakes, throttle, and steering are not mechanically connected they are all electronic. When the car auto brakes it will just slow to a stop, now if you put your foot on the pedal it will feel the same as normal, it does not move on its own and only has a short built in range into it to give the appearance of a firm well adjusted brake.
Takes a little getting used to, kind of like the steering, if you notice for example if you it bump on one side the car compensates for it and the steering wheel doesn't jerk around.
Takes a little getting used to, kind of like the steering, if you notice for example if you it bump on one side the car compensates for it and the steering wheel doesn't jerk around.
If I'm using cruise control there is no change in how the brake pedal feels. A couple times I've been driving "manually" and the car in front of me brakes a little so I brake, followed by VERY hard braking by the car in front of me which has kicked in the "auto brake" feature he's asking about.
The pedal DEFINITELY moves differently. It almost feels like it falls to the floor or something. I don't think it's really moving on its own but it's as if suddenly there's no pressure needed to brake 100%. It's hard to explain but the sensation is altogether different than "normal braking".
Man I said brake a lot.
Member
Joined: Nov 2016
Posts: 88
Likes: 13
From: Long Island, NY
2014 Mercedes Benz E350 Sport 4matic
I have to disagree. I have a 2011 E550 with distronic etc.
If I'm using cruise control there is no change in how the brake pedal feels. A couple times I've been driving "manually" and the car in front of me brakes a little so I brake, followed by VERY hard braking by the car in front of me which has kicked in the "auto brake" feature he's asking about.
The pedal DEFINITELY moves differently. It almost feels like it falls to the floor or something. I don't think it's really moving on its own but it's as if suddenly there's no pressure needed to brake 100%. It's hard to explain but the sensation is altogether different than "normal braking".
Man I said brake a lot.
If I'm using cruise control there is no change in how the brake pedal feels. A couple times I've been driving "manually" and the car in front of me brakes a little so I brake, followed by VERY hard braking by the car in front of me which has kicked in the "auto brake" feature he's asking about.
The pedal DEFINITELY moves differently. It almost feels like it falls to the floor or something. I don't think it's really moving on its own but it's as if suddenly there's no pressure needed to brake 100%. It's hard to explain but the sensation is altogether different than "normal braking".
Man I said brake a lot.
Senior Member
Joined: May 2015
Posts: 326
Likes: 3
2011 E550
Right I agree. I probably worded it incorrectly. I meant it like its not motorized, like if you look at the brake pedal while its doing it, it doesn't move, however pressing the pedal while its already braking is of course different because part of that programmed range has already been accounted for.
