Automatic Emergency Braking

Battin4th · 03-11-2021, 04:34 PM

2019 m40i with the Driving Assist and Parking Assist packages. So here's the story...

I'm driving along at a pretty good clip in the left lane of the expressway. Speed limit 65, I'm doing maybe 80 which is not usual for this stretch of road. I'm coming up on an entrance ramp and a slow moving truck in the right lane. I see a Subaru STI coming on to the entrance ramp at the usual stupid speed.

From the Subaru speed, I know that he is going to want to flip into the left lane to avoid crashing into the back of the truck, and probably doesn't even see me. Judging his speed, my approach speed and the slow moving truck, I also know he won't have the room to get in in front of me, if I don't hit the brakes. So, as all this unfolds exactly as I thought it would, he comes over to the left lane, without seeing me. I was all ready to hit the brakes which I did, but it seemed the car may have decided to do the same thing at the same time. I stepped on the brakes but not hard enough to cause the ABS to activate, however it did. Audible noise, peddle pulses, etc...

So my question, will the car apply AEB at that speed? It seems to have done that, and I do not have the "advanced" driving package (or whatever it was called) that enables the self driving/self following capabilities.

I know, I should of just slowed down sooner, but I knew I wasn't going to let it happen anyway.

eX3Werks · 03-11-2021, 05:34 PM

I think you're talking about the automatic emergency braking in the front collision assist? I believe that is standard on all models with or without the advanced drivers package.

Battin4th · 03-11-2021, 06:19 PM

Yeah I guess I'm talking about front collision assist. There is no mention of it in anything I have seen in writing with respect to my optioned car. And I assumed it would only be available with the driver assistance "plus" package. I have seen frontal collision behavior differentiated between "city" and "highway" by BMW. The main differentiator being how fast you are going and whether and how the car reacts.

I suppose its possible that "emergency brake assist" primed the brakes for me, and when I stepped on them, the immediate reaction (and seemingly ABS) surprised me.

freshxdough · 03-11-2021, 10:52 PM

Quote:

Originally Posted by Battin4th

Yeah I guess I'm talking about front collision assist. There is no mention of it in anything I have seen in writing with respect to my optioned car. And I assumed it would only be available with the driver assistance "plus" package. I have seen frontal collision behavior differentiated between "city" and "highway" by BMW. The main differentiator being how fast you are going and whether and how the car reacts.

I suppose its possible that "emergency brake assist" primed the brakes for me, and when I stepped on them, the immediate reaction (and seemingly ABS) surprised me.

The braking function will do this. It is to be able to have the driver brake immediately instead of push all the way down to get full braking pressure.

spangle1980 · 03-12-2021, 02:31 AM

For sure it will apply AEB at speed - you don't think it cuts off above a certain threshold do you? I think that story is totally cool, and a good example how the tech may have saved you from a certain pain :-)

Of course it wouldn't care about the loser behind you tailgating ;-). There again not really a lot it could do there I suspect?

rob175 · 03-12-2021, 07:14 AM

I'm not sure.....yesterday as was in the right exit lane and traffic was backed up in the left traffic lane a taxi suddenly pulled out in front of me....NO RESPONSE from the car but no matter, I slammed on the brakes and avoided t-boning the taxi. If there was ever a time some sort of assist would have been nice, that was the time! Occasionally, I've seen the "red car symbol" warning appear in the center of the instrument panel but that's all, just a display of the symbol.....no braking action....just the symbol. I don't have any "assist" package, just the standard stuff.

Guess I don't understand the system and the owners manual doesn't really explain.

GGEVOX · 03-12-2021, 07:17 AM

I had mine slam on the brakes yesterday evening. It was going downhill. I was above the posted speed but in flow with traffic. I wondered if it was the combo of reading the speed signs and going downhill. I also do not have any additional packages. Just the parking assist. Made the dresser in the back hatch hit my back seats and piss me off.

Battin4th · 03-12-2021, 08:45 AM

Quote:

Originally Posted by spangle1980

For sure it will apply AEB at speed - you don't think it cuts off above a certain threshold do you? I think that story is totally cool, and a good example how the tech may have saved you from a certain pain :-)

Of course it wouldn't care about the loser behind you tailgating ;-). There again not really a lot it could do there I suspect?

My main purpose was to share the event and the experience in the event it might help someone. Maybe also to spark some debate.

But yes, I will assert that many vehicles and manufacturers do not have their systems intervene at highway speeds. For the reasons stated in some of the posts already. Occupants potentially flying around the cabin, objects flying around the cabin and yes, the taligator.

I have seen literature and videos from BMW where they make the distinction (on at least some of their vehicles) between city avoidance (low speed) and highway avoidance (high speed).

eX3Werks · 03-12-2021, 11:43 AM

That is interesting they would differentiate between hwy and city speeds like that. Unless it's a hardware limitation I feel they should still work at hwy speeds. I guess for me, having things fly around in the cabin is better than getting killed? Lol but I get the part about tailgating, but there's nothing you can do if someone is going to rear end you.

Not sure if I remember it correctly but while reading the manual it mentioned something about prepping for rear collision. Your car would apply the brakes if it senses a collision from the rear. Not sure if this is a standard feature.

titomi · 03-12-2021, 01:23 PM

Quote:

Originally Posted by eric_88

That is interesting they would differentiate between hwy and city speeds like that. Unless it's a hardware limitation I feel they should still work at hwy speeds. I guess for me, having things fly around in the cabin is better than getting killed? Lol but I get the part about tailgating, but there's nothing you can do if someone is going to rear end you.

Not sure if I remember it correctly but while reading the manual it mentioned something about prepping for rear collision. Your car would apply the brakes if it senses a collision from the rear. Not sure if this is a standard feature.

preparing brakes for rear collision ? that doesn't make sense

As far as I know, there is only lights warning for the incoming traffic and some.kind of "pre-crash" functions triggered.

eX3Werks · 03-12-2021, 02:23 PM

What I meant is if your car is at a standstill and you get rear ended. It'll apply the brakes for you so you don't in turn rear end someone else.

yakuza · 03-13-2021, 12:26 PM

Quote:

Originally Posted by eric_88

What I meant is if your car is at a standstill and you get rear ended. It'll apply the brakes for you so you don't in turn rear end someone else.

Exactly, also if you're first on crossroad you may avoid being t-boned thanks to this.

03-11-2021, 04:34 PM	#1
Battin4th Private First Class 141 Rep 112 Posts Drives: BMW X3 M40i Join Date: Mar 2019 Location: MD iTrader: (0)	Automatic Emergency Braking 2019 m40i with the Driving Assist and Parking Assist packages. So here's the story... I'm driving along at a pretty good clip in the left lane of the expressway. Speed limit 65, I'm doing maybe 80 which is not usual for this stretch of road. I'm coming up on an entrance ramp and a slow moving truck in the right lane. I see a Subaru STI coming on to the entrance ramp at the usual stupid speed. From the Subaru speed, I know that he is going to want to flip into the left lane to avoid crashing into the back of the truck, and probably doesn't even see me. Judging his speed, my approach speed and the slow moving truck, I also know he won't have the room to get in in front of me, if I don't hit the brakes. So, as all this unfolds exactly as I thought it would, he comes over to the left lane, without seeing me. I was all ready to hit the brakes which I did, but it seemed the car may have decided to do the same thing at the same time. I stepped on the brakes but not hard enough to cause the ABS to activate, however it did. Audible noise, peddle pulses, etc... So my question, will the car apply AEB at that speed? It seems to have done that, and I do not have the "advanced" driving package (or whatever it was called) that enables the self driving/self following capabilities. I know, I should of just slowed down sooner, but I knew I wasn't going to let it happen anyway.
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03-11-2021, 05:34 PM	#2
eX3Werks Private First Class 89 Rep 141 Posts Drives: BMW X3 M40i Join Date: Jan 2021 Location: Vancouver, BC iTrader: (0) Garage List 2018 BMX X3 M40i [0.00]	I think you're talking about the automatic emergency braking in the front collision assist? I believe that is standard on all models with or without the advanced drivers package.
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03-11-2021, 06:19 PM	#3
Battin4th Private First Class 141 Rep 112 Posts Drives: BMW X3 M40i Join Date: Mar 2019 Location: MD iTrader: (0)	Yeah I guess I'm talking about front collision assist. There is no mention of it in anything I have seen in writing with respect to my optioned car. And I assumed it would only be available with the driver assistance "plus" package. I have seen frontal collision behavior differentiated between "city" and "highway" by BMW. The main differentiator being how fast you are going and whether and how the car reacts. I suppose its possible that "emergency brake assist" primed the brakes for me, and when I stepped on them, the immediate reaction (and seemingly ABS) surprised me.
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03-12-2021, 02:31 AM	#5
spangle1980 Deadly 1315 Rep 2,070 Posts Drives: X3 M40d BG LCI Join Date: Jun 2018 Location: UK iTrader: (0)	For sure it will apply AEB at speed - you don't think it cuts off above a certain threshold do you? I think that story is totally cool, and a good example how the tech may have saved you from a certain pain :-) Of course it wouldn't care about the loser behind you tailgating ;-). There again not really a lot it could do there I suspect?
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03-12-2021, 07:14 AM	#6
rob175 Major 688 Rep 1,115 Posts Drives: BMW X3 xiDrive30 Join Date: Feb 2020 Location: Illinois iTrader: (0)	I'm not sure.....yesterday as was in the right exit lane and traffic was backed up in the left traffic lane a taxi suddenly pulled out in front of me....NO RESPONSE from the car but no matter, I slammed on the brakes and avoided t-boning the taxi. If there was ever a time some sort of assist would have been nice, that was the time! Occasionally, I've seen the "red car symbol" warning appear in the center of the instrument panel but that's all, just a display of the symbol.....no braking action....just the symbol. I don't have any "assist" package, just the standard stuff. Guess I don't understand the system and the owners manual doesn't really explain.
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03-12-2021, 07:17 AM	#7
GGEVOX Second Lieutenant 63 Rep 201 Posts Drives: G01 M40i, F36 440xi Join Date: Apr 2016 Location: Wisconsin iTrader: (0)	I had mine slam on the brakes yesterday evening. It was going downhill. I was above the posted speed but in flow with traffic. I wondered if it was the combo of reading the speed signs and going downhill. I also do not have any additional packages. Just the parking assist. Made the dresser in the back hatch hit my back seats and piss me off.
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03-12-2021, 11:43 AM	#9
eX3Werks Private First Class 89 Rep 141 Posts Drives: BMW X3 M40i Join Date: Jan 2021 Location: Vancouver, BC iTrader: (0) Garage List 2018 BMX X3 M40i [0.00]	That is interesting they would differentiate between hwy and city speeds like that. Unless it's a hardware limitation I feel they should still work at hwy speeds. I guess for me, having things fly around in the cabin is better than getting killed? Lol but I get the part about tailgating, but there's nothing you can do if someone is going to rear end you. Not sure if I remember it correctly but while reading the manual it mentioned something about prepping for rear collision. Your car would apply the brakes if it senses a collision from the rear. Not sure if this is a standard feature.
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03-12-2021, 02:23 PM	#11
eX3Werks Private First Class 89 Rep 141 Posts Drives: BMW X3 M40i Join Date: Jan 2021 Location: Vancouver, BC iTrader: (0) Garage List 2018 BMX X3 M40i [0.00]	What I meant is if your car is at a standstill and you get rear ended. It'll apply the brakes for you so you don't in turn rear end someone else.
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