How does automatic braking decide to activate?

[2nd 392]

My GC doesn’t like turn lanes, especially in a curve, slams on the brakes , I finally figured it out after the 3’rd time when nearly getting rear ended in the same curve, getting the expected hand signals and my intelligence loudly questioned. My wife loves the ACC that requires it on, now take the long way when driving it. Fortunately my Wrangler is not so inclined.

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[Byron]

Is it always in the exact same spot? Cameras work on reflections and the paint on the floor along with the sunlight reflecting going from shaded area causing the sensors and light to bounce back. does it do the same thing at night? If not it’s the paint and light reflections. it’ll do it too when sun is just right and behind another truck with chrome bumper

Yes, it's always that spot. Either North or Southbound lanes both trigger it. It's never gone off anywhere else that wasn't justified. That's why I was thinking it could be something in or part of the bridge. Good point with the reflections though, I've never been through there at night.

 

[Byron]

My GC doesn’t like turn lanes, especially in a curve, slams on the brakes , I finally figured it out after the 3’rd time when nearly getting rear ended in the same curve, getting the expected hand signals and my intelligence loudly questioned. My wife loves the ACC that requires it on, now take the long way when driving it. Fortunately my Wrangler is not so inclined.

I love the ACC too, I'll never have another vehicle without it. I have limited patience for people who behave unpredictably (call it road rage, whatever). When my Jeep slams on the brakes randomly, it makes me one of the people that I hate!

 

[JINO]

Might have figured out how to post a video of this nonsense.

Oh no, that is definitely not normal.
That's the first time I've heard of that happening in a JL. Mine has that too. I turned mine off, because it was annoying. I would be terrified if that happened going up and down a mountain, I live at 7000' and work at 10', and a lot of miles.
Mine would beep when someone cuts me off, but it's never activated the brakes.

 

[sunset]

Yes! you can adjust it through UConnect, which I didn't know until just now. You can adjust sensitivity, turn it all the way off or just set it to beep without applying the brakes. I'm excited because this thing is dangerous!

Can you please tell me/us what settings you found this feature set at, before you change the settings for it?

Also, if you keep that video on youtube, may I suggest adding remarks there to say what year and trim you have, the fact that it was stock, and what the option and settings were that caused the braking, and what you did that fixed it? That's so guys like me who stumble upon such "silent" videos (and there are many of them on YT) can read and learn.

 

[Byron]

Can you please tell me/us what settings you found this feature set at, before you change the settings for it?

Absolutely! In Apps, Settings, Safety & Driving Assistance on the UConnect. I have the 8.4" but I would think the other ones are similar. It's Forward Collision Warning and Sensitivity. I just found these settings thanks to @Mx5red and adjusted but haven't tested them yet.
I'm not here to tell people what to do with their own vehicles, but I would encourage everyone to look into this thing and make an educated choice. Yeah it might stop you from running into someone else. Or just pay attention to where you're going, turn this death trap off and keep yourself from getting rear-ended. Just want you to see what happens. Beep then total lockup. @Vinman had them lock up at speed, I was just going about 10. Crazy.
As for the video, I can add the remarks, I think. Will give it the old college try

 

[Jbudz511]

There's something with the change in lighting in those scenarios. I've turned the braking portion off immediately when I purchased. I've left the brake warning on at medium sensitivity and it's generally unobtrusive, but helpful in a few scenarios I will admit.

But i have noticed one or two situations during rain when approaching an overpass/tunnel and it's gray etc. one was in bumper to bumper. The other was at speed. Don't think it's tripped in clear conditions ever. Glad i have the brake off lol.

 

[Kbinspections]

That is a crazy video and definitely not correct. Maybe there is some outside signal source interference near the bridge. Head to the dealer with that issue! NSTB if they can’t get an answer

Jeeps system is on the crude side when compared to my Acura. Acura system is much more refined and brakes progressively. Jeep seems to go right to emergency braking!
Acura also has less false positives. Both systems seem to have issues with acute curves in the road.

I still think they are worth it. It saved me from an accident once.

 

[Byron]

I still think they are worth it. It saved me from an accident once.

Right? It can save you from an accident or cause an accident. I'm still torn on this one but after today, it's disabled for now.

Edit: The only reason I didn't get hit was the car behind me was a brand new shiny red Camaro and he was paying attention and also locked up his brakes. Had it been Sally-texts-alot behind me, I'd be in the shop, and who would be at fault? I'm pretty sure me even though I had nothing to do with it.

 

[Kyanche]

I watched the video and this one doesn't make any sense to me at all lol. Yea it might be some weird radar feedback too.

 

[Gnomad]

There’s a 2lane road by my house that has a moderate curve. Halfway through the curve is a mailbox on a brick pillar right up next to the asphalt.

When I first got my JL it would beep and slam on the brakes every time I passed that mailbox.

Shut the system off and never looked back!

 

[Bill_BCNtoNY]

That is a crazy video and definitely not correct. Maybe there is some outside signal source interference near the bridge. Head to the dealer with that issue! NSTB if they can’t get an answer

Jeeps system is on the crude side when compared to my Acura. Acura system is much more refined and brakes progressively. Jeep seems to go right to emergency braking!
Acura also has less false positives. Both systems seem to have issues with acute curves in the road.

I still think they are worth it. It saved me from an accident once.

Interesting - maybe Honda/Acura have a better system. Although, as a counterpoint, my Volvo XC60 also has phantom panic attacks on the highway every now and then.

I'd say I experience these fake emergency braking alerts about once a month - and I drive <10k mi per year, approximately 80% in the Volvo and 20% in the Jeep. To me, that is way more than acceptable... but ACC is just too comfy to give up on long drives, too.

 

[BobW]

Years ago, my Chevy Malibu ran with brake lights always on, until you pressed brake pedal and the lights went off. True story. I recall finding a tech alert indicating the cause was one specific plug/socket in which pins needed to be lubed with special conductive grease. That cured it (unplugging & reconnecting did not).
The point? It was a subtle cause in a system simple compared to ACC.

 

[TrentYoung]

Every day when I go under this specific bridge (in either direction), the dash turns red, Brake! flashes and it beeps. Today however, the Jeep locked up the brakes for me. Almost got hit as a result, wasn't that thrilled with the experience, and the guy behind me had some choice gestures to share (which I don't blame him at all).

Does anyone know what the Jeep uses to make the decision that you are about to hit something? And does anyone see anything about this particular bridge that would set it off? The system does work, it has beeped when I'm using the adaptive cruise control and people decide to change lanes for no reason. But it has never actually stopped the vehicle. And it beeps every time I go under this bridge.

Now I'm scared of it, can it just lock up the brakes going down the highway because it sees a bird it doesn't like or something?
Thanks!
-Byron

It is a typical action that is contrary to your reader unit. It is seeing that "particular"bridge as an obstruction just by the volume, angle, and approach of your jeep. It is a typical action inn 99% of most semi truck that have forward warning restriction. Imagine 80,000 lbs having the same thing happen. Usually there is a very short warning that it is about to slam on the brakes. Only real way to stop it is to not use your adaptive cruise control.

 

[Ratbert]

Only real way to stop it is to not use your adaptive cruise control.

You seem to be ignoring the most obvious way to stop it: get it fixed. It's broken.

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