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Discussion Starter · #1 ·
So twice now the brake intervention system has intervened on ghosts. Once in the garage and today in the driveway. Absolutely nothing was behind. Today I even got outside and checked just to be sure.
As anyone that's had the system intervene knows, it doesn't mess around, it stops you dead in your tracks. But I can't have it alerting like that, especially if other people are in the car, so I'm considering disabling it.
But doing so rather bothers me, as that seems in general like a bad idea, because when I really use it I'm probably going to be very glad that it is there.
What experiences have others had?
 

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'21 XC40 Recharge P8 Sage Green
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Haven’t had “ghosts” but it did unexpectedly slam on the brakes twice this fall, due to a pile of un-raked leaves dancing in the wind while backing up my steep driveway. Note to self: get out that leaf blower.

All other occurrences have been real cars/pedestrian/bicyclists, where one would expect it.
 

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You can easily disable it by tapping the button on the backup camera display, but you have to do it every time. Only way I’m aware of to “permanently” disable it is to plug in a “fake” trailer hitch electrical hookup.
 

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You can easily disable it by tapping the button on the backup camera display, but you have to do it every time. Only way I’m aware of to “permanently” disable it is to plug in a “fake” trailer hitch electrical hookup.
Ohhhh…..I didn’t think of that. I turn it off every time I back into our garage and that’s annoying. I would want the backup sensors to work though….Volvo really needs a way to permanently turn that off and leave the sensors on. I do not like the auto brake feature….quite despise it.
 

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Auto brake is annoying when it is a faulty deployment that shakes you up and spills your coffee.

Auto brake is priceless when it stops the car from running over your five year old …your cat … your dog … random pedestrian who shot out behind you.

How fast are folks going when it deploys? I wonder if faster makes it deploy more and of course jolt a lot more.
 

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mine false pos deployed tonight - scared the bejeezus out of my wife. we were going <5mph out of the carport and BAMBLAMBAM abrupt stop. it really is jarring. nothing was there. that has only happened to me once before though. when it works it works. i swear though I've almost backed into things and it doesn't fire, so who knows
 

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You can easily disable it by tapping the button on the backup camera display, but you have to do it every time. Only way I’m aware of to “permanently” disable it is to plug in a “fake” trailer hitch electrical hookup.
Just FYI using a fake (or real) trailer light hookup disables RAB but it also disables blind spot monitoring. So not the best permanent solution. There is a lot of discussion on this topic in the various trailer hitch / bike rack threads.
 

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I've had it deploy twice and my wife twice. I told her about it so she wouldn't think that something was wrong. As prepared as you can be it is always a surprise. One of mine was backing out of the garage (yes car, you will need to get close to things to get out of the garage). Hers were also backing out of the garage. My other auto brake deployment was backing into the garage. It does not matter how slow you are going, it is still a shock, as if you just hit something (without the noise if crunching metal and plastic).
 

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I've had it deploy twice and my wife twice. I told her about it so she wouldn't think that something was wrong. As prepared as you can be it is always a surprise. One of mine was backing out of the garage (yes car, you will need to get close to things to get out of the garage). Hers were also backing out of the garage. My other auto brake deployment was backing into the garage. It does not matter how slow you are going, it is still a shock, as if you just hit something (without the noise if crunching metal and plastic).
The first time it happened, I thought I was about to have a heart attack because it was in my wife’s XC40 and we had just gotten it. I was like oh great, she’s never going to let me forget about this one because I thought I just hit something backing into the garage.
 

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The first time it happened, I thought I was about to have a heart attack because it was in my wife’s XC40 and we had just gotten it. I was like oh great, she’s never going to let me forget about this one because I thought I just hit something backing into the garage.
I read about it happening to other people. Then it happened to me. I told her about it so that she was ready. Now she not so calmly tries to explain to the car that it needs to get close to things in order to get out of the garage.
 

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Yeah, I despise this system. It wouldn’t be so bad if it just added partial braking, along with a unique audio warning. But it totally locks the brakes instantly, so you feel like you just hit a brick wall, which is what I thought we did the first time I felt it. It seems to be better after the 1.8 update, at least for us. But for the first 6 mos of ownership, I had my wife disengage the system every time she backed up. She was in tears the first time it happened to her, and thought she hurt her neck when it fired off.
Automotive design Motor vehicle Gadget Automotive exterior Gas
 

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It's happened to me twice as well. It's literally terrifying. Once was at a parking spot at work where tall grass was behind the parking spot the sensors caught on that; the other was backing into our garage that has a slight slope off the street. Going from 4-5 MPH to a complete stop in less than a tenth of a second is terrifying. It's far too sensitive even after they toned it down in 1.7. Don't get me wrong I'll be thankful when I actually need it but holy **** your heart rate spikes to 150.

For what it's worth I think it's because of the XC-40s height. We have a 2021 XC-90 we drive the exact same way and it's never had a false positive.
 

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Discussion Starter · #14 ·
For my two instances, one was 1.7 and the other 1.8.1. Both were moving very slowly (backing into garage + backing out of driveway), and no apparent wind/grasses/leaves/bugs etc that would have maybe triggered the sensor. Obviously something did but no idea what.
 

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For my two instances, one was 1.7 and the other 1.8.1. Both were moving very slowly (backing into garage + backing out of driveway), and no apparent wind/grasses/leaves/bugs etc that would have maybe triggered the sensor. Obviously something did but no idea what.
I wonder if a fly could trigger it?

**** shame it does not store the last 2 seconds of video it uses to process impacts so it could diagnoses false positives.

Emergency brakes were applied
Was there anything to hit yes/no
If no either locally update the ai used or send it to Volvo so they can update/diagnose the fail.
 

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My wife was outside looking at her XC40 and I thought it was odd that she didn’t put it in her garage. She was freaking out because she thought she hit the house because the car instantly stopped because of the rear auto brake. I started laughing, which she didn’t find amusing, and I told her it was because of the auto brake. I had it do it to me in the exact spot she had stopped in…..I told her she needs to just turn that off as soon as she starts backing up.

SuperAnnoying!!! This is probably the one thing I hate the most about the XC40…..I can handle the bugs, but this is super annoying and PIA.
 

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Happened to me 3 times now. Twice backing out of the garage with nothing behind me. I thought I hit something, and just about had a heart attack! Did get whiplash, so back out really slow now! The third time a dog ran behind me and my wife while backing up at a family members house. Probably saved the dogs life.
 

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Happened to me 3 times now. Twice backing out of the garage with nothing behind me. I thought I hit something, and just about had a heart attack! Did get whiplash, so back out really slow now! The third time a dog ran behind me and my wife while backing up at a family members house. Probably saved the dogs life.
I just had the same thing happen to me yesterday. My next door neighbor constantly lets her dogs out off leash. Was backing out of the garage to go to dinner and the rear auto braking went off just as one of them was running across the driveway. I've only had one false positive with the system even with our steep and curved driveway. I'll settle for that if it prevents a tragedy even once.
 

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I’m glad we have the gesture. As abrupt as it is I rather not hit something or somewhat I didn’t mean to hit.
I’ve learned that if I’m backing up into the garage and I’m sure the coast is clear I disable auto break.
 
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