Well three G's in and over 14k total miles, it finally happened - the G was spooked by its own shadow and slammed on the brakes by itself.

I've had it happen before when reversing out of my garage which was scary for a second but then annoying. Today was really scary because of what could have been, but fortunately nobody was behind me.

I was crossing a green light and a railroad track was ahead and the car must have thought the track and the sun reflecting off it was a car, so it beeped then slammed on the brakes. There was an icon that appeared on the left screen with a white triangle and then it went away.

I'm not sure if you can override it with the gas because it happened so fast. Well I guess it's another step after turning off LKAS I'll have to turn this off as well.

 

..I once left 10 foot long skid marks when the G got spooked over a steel plate cover on the road..the only saving grace being the automatic emergency braking keeps the vehicle straight.

 

Just so you know, turning it "off" doesn't completely turn it off. It just sets it to the lowest sensitivity.

 

Interesting. Because when I turn it off it puts the icon on the dash. Maybe I’ll try low if it remembers that setting and just watch out for railroad crossings in the future.

I drive on that road very often so it was weird for it to happen.

 

I never tailgate other drivers because I assume they're idiots susceptible to doing stupid things like braking hard at the last minute in order to not miss making a turn, or to avoid driving over a prairie dog. With more and more automobiles being equipped with ADAS systems that include ABA, here's yet another reason to maintain a safe distance from the vehicle in front of you. Perhaps vehicles equipped with ABA should have rear mounted signs as the metro buses do, "vehicle makes sudden stops" (lol).

 

Low is higher sensitivity than "off". Turning it off is part of my routine (same with LKA and auto start/stop). Was just letting you know that off doesn't truly mean off. Source: my Merc tech.

 

Had my LKA and Auto Start/Stop permanently turned off. Definitely great to to just start up and drive without holding here for 3 seconds and pushing this button.

 

My skid mark would have been in my pants, that’s terrifying!

 

Right--I meant I wonder if I switch to low will it stay at low so I don't have to keep turning off as the hope is low is "low" enough.

Anyway for now I'll keep doing it. I drove the same road at the same time of day on "off" and no drama.

 

How did you turn it off? I can't seem to find that option... Thanks!

 

Sure:

-Home screen scroll to Vehicle
-Go to Assistance
-Go to Active Brake Assist
-Choose between Early/Medium/Late/Off

Edit: I switched it to Late this morning (not low as I previously said) and it keeps that setting. However if you turn it off it’ll revert back to medium next startup.

 

This has got to be the most annoying thing and it is scary.

 

A couple questions:

1) Active brake assist is the collision detecting warning thing? Because I've had this happen to me randomly twice as well where the car just suddenly slams the brakes for no apparent reason, thinking some sort of obstacle is inbound...

2) To be clear I assume this is like LKA and A/S/S that you have to manually toggle off on every startup? I switch both off immediately entering the car, LKA implementation is so horrifically bad and dangerous I have no idea why a recall hasn't been issued yet to delete the actual braking side of it or just rid of it completely

edit - just read your comment about if it's set to late OK memory is kept, if you set it to off memory is NOT kept...

 

Yes this was the car making the warning tone then slamming on brakes with nothing in front. An alarm screen came up on the left side of the dash.

I guess the one good thing is the brakes are really strong.

This is the most annoying feature to me with new cars. Most force you to turn it off every time for safety reasons. I always keep a far distance from cars and pay attention to the road.

 

This same discussion about active braking / collision avoidance is happening on one of the BMW forums I follow. I haven't yet experienced it, and hope not to ever in the future. It seems as if when active braking takes over, you the driver revert to passenger class, and are simply along for an adventure ride. Seems much like Boeing's 737 MCAS that pushed the nose of the aircraft down due to a faulty sensor, and the pilots were helpless to counteract it.

Several years ago, I was driving in blizzard conditions, creeping along at only about 25 mph. The truck I was following suddenly turned sideways in front of me, and I was on a collision course to T-bone it. I averted disaster by accelerating and moving into the adjacent lane in front of another vehicle that had been next to me. It seems that active braking would prevent such a maneuver and would assist me in assuring a collision. ABS would have aided by ensuring perfect collision trajectory.

 

another update..happens on reverse too..happened a couple of times. was reversing at a crawl and for some reason it kicked in and it sounded like my rear bumper scraped the parking stall concrete "stops". when I got out and looked to see if I had scraped the bumper, not only was the G a full couple of metres away, the bumper was way higher than the concrete. it only occurred to me later that it was the vehicle that did that. like I said it's not a quick stop but will sound like you are scraping something slowly.