False positives & Unwarranted braking - Collision Mitigation Braking System

I'm close to buying a 2019 Civic EX hatchback to replace my 2006 Civic EX sedan. It comes standard with Honda Sensing.

A couple reviews (Edmunds among them) complained about excessive false positives with the Collision Mitigation Braking System, and a few owners reported unfounded emergency braking -- the system brakes hard in an inappropriate situation. The comments were from in 2018 though and I suspect they apply to that model.

I like the idea of the safety features but sure wouldn't want the car to make an unwarranted emergency stop. I wonder if the CMBS was tweaked for 2019 to reduce false positives? Does anyone have experience with that feature in a 2019 Civic?

Also, is there a button to turn it off or do you have to go into the menu system. I looked at the owner's manual and there's a heading "Turning the System On or Off" but no info with it.

Thanks!

We have it on our 2018 Odyssey and it very rarely does that. No matter how much they "tweak" it, it is still a computer with only one eye facing forward. It does not sense your thoughts or future actions, and only goes by what the radar is inputting to the computer.

civicls said:

We have it on our 2018 Odyssey and it very rarely does that. No matter how much they "tweak" it, it is still a computer with only one eye facing forward. It does not sense your thoughts or future actions, and only goes by what the radar is inputting to the computer.

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Thanks. I don't expect perfection, and an occasional false positive beep is no problem. However the Edmunds review made it sound like there were a lot of them.

More importantly, I read four different posts (on other car forums) from people who'd had the system make an emergency stop when there was no obstacle.

In one case they said there was a garbage can near the road but not in it. In two other instances people said the CMBS stopped the car when they were making a left turn on an arrow at an intersection, and the car opposite was doing the same. Apparently the system detected the opposite turning car as coming at them. And the last report said there was nothing in or near the road -- the CMBS just stomped the brakes for no reason.

I guess you've not encountered anything like those situations?

If you find it’s overly sensitive for your tastes there are levels of sensitivity you can choose in the settings, as well at the ability to turn it off entirely.
Personally I lowered it one step down from the default as I found it throwing more warning than I liked.

False positive hard breaks don’t appear to be a rampant, common, or even uncommon issue.
The warnings you just get used to really.
They aren’t intrusive and are mostly accurate but generally something you already see coming and are reacting to.

For me the one time it did hard brake was in fact the one time I’d have accelerated right into the car in front of me ,having misjudged how fast traffic was picking up, and it didn’t let me. So I’m happy for it personally.

lightthief said:

If you find it’s overly sensitive for your tastes there are levels of sensitivity you can choose in the settings, as well at the ability to turn it off entirely.
Personally I lowered it one step down from the default as I found it throwing more warning than I liked.

False positive hard breaks don’t appear to be a rampant, common, or even uncommon issue.
The warnings you just get used to really.
They aren’t intrusive and are mostly accurate but generally something you already see coming and are reacting to.

For me the one time it did hard brake was in fact the one time I’d have accelerated right into the car in front of me ,having misjudged how fast traffic was picking up, and it didn’t let me. So I’m happy for it personally.

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Great, that's good to hear.

The posts I saw with complaints about false positives said they had turned it down to the lowest setting but were still getting them. However that doesn't concern me as much as unneeded braking.

I'm deciding between the Civic hatchback and Subaru Crosstrek. The Civic is a ton more fun to drive and it's where my heart is, but I want to be intelligent about safety as well.

Thanks.

BataviaJim said:

Great, that's good to hear.

The posts I saw with complaints about false positives said they had turned it down to the lowest setting but were still getting them. However that doesn't concern me as much as unneeded braking.

I'm deciding between the Civic hatchback and Subaru Crosstrek. The Civic is a ton more fun to drive and it's where my heart is, but I want to be intelligent about safety as well.

Thanks.

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This version of the Civic has been around since Dec 2015. Think of the juicy peach of a national news story of AI going crazy if unwarranted hard brakes were anything but super rare. Obviously no system is ever going to be 100% perfect but the system they’ve worked out, while still Version 1 of a commercial system , has been through its paces enough to never really be a hazard rather than a safety feature. The series of steps it’s going through before it decides a full stop is the right response is really extensive.
It does have to decide that a warning, a stronger warning, a soft brake, a medium brake, etc etc etc are all the wrong choice before it takes control from you entirely. It’s not just itching to stop you whenever it can. That is the last possible step in a long series of steps.


Most of the places it can fall short are the places you would as well, judging if something at a distance is heading directly at you, or just (potentially) headed very close to you based on where it is right now and where it might be in a few seconds.

Honda and other companies don’t publicly lay out all the decision trees at play. I go back and forth on whether that is good or bad but it’s probablt for the best. Some
Idiots would probably try and game it somehow for some dumb reason.
But as far as I’m aware they haven’t announced publicly any changes or improvements between years since it’s introduction.

lightthief said:

This version of the Civic has been around since Dec 2015. Think of the juicy peach of a national news story of AI going crazy if unwarranted hard brakes were anything but super rare. Obviously no system is ever going to be 100% perfect but the system they’ve worked out, while still Version 1 of a commercial system , has been through its paces enough to never really be a hazard rather than a safety feature. The series of steps it’s going through before it decides a full stop is the right response is really extensive.
It does have to decide that a warning, a stronger warning, a soft brake, a medium brake, etc etc etc are all the wrong choice before it takes control from you entirely. It’s not just itching to stop you whenever it can. That is the last possible step in a long series of steps.


Most of the places it can fall short are the places you would as well, judging if something at a distance is heading directly at you, or just (potentially) headed very close to you based on where it is right now and where it might be in a few seconds.

Honda and other companies don’t publicly lay out all the decision trees at play. I go back and forth on whether that is good or bad but it’s probablt for the best. Some
Idiots would probably try and game it somehow for some dumb reason.
But as far as I’m aware they haven’t announced publicly any changes or improvements between years since it’s introduction.

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Good points. I had been thinking that Honda Sensing was fairly new to the Civic, but I guess that's because it's newly standard this year. I guess it's been an option for a couple years at least, so you're right

I can disable mine with a push of a dash button. But it's not sticky. I have to disable it every time I start the car.

I have had Civic Sport for six month now. There was one false positive where the car tried to brake in a complex traffic situation (I am in Israel, everyone drives like crazy here, the traffic situation is always complex), there was no good reason for that. I instinctively quickly pressed the gas pedal and it immediately cancelled CMBS braking. Later I found in the manual that it is the way to deactivate CMBS.
Other than that there were no issues with it and there were no "positive positive" situations to test it (I drive defensively). In fact I do like CMBS visual-only alerts, they typically happen when a car I am following brakes hard, typically I see the alert exactly at the time I am about to apply brakes and it confirms my feelings that I should brake harder than usual this time.
I was extremely skeptical about CMBS when I bought the car, but now I would not turn it off or even change the sensitivity, especially since I know it that CMBS breaking can be cancelled if necessary right off by pressing the gas pedal.

shoegazer said:

I can disable mine with a push of a dash button. But it's not sticky. I have to disable it every time I start the car.

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Thanks, that's one of the things I wanted to know. I thought, but hadn't been able to confirm, that there's an on/off button. It would be a hassle to have had to go into the menu every time.

MDB said:

I have had Civic Sport for six month now. There was one false positive where the car tried to brake in a complex traffic situation (I am in Israel, everyone drives like crazy here, the traffic situation is always complex), there was no good reason for that. I instinctively quickly pressed the gas pedal and it immediately cancelled CMBS braking. Later I found in the manual that it is the way to deactivate CMBS.
Other than that there were no issues with it and there were no "positive positive" situations to test it (I drive defensively). In fact I do like CMBS visual-only alerts, they typically happen when a car I am following brakes hard, typically I see the alert exactly at the time I am about to apply brakes and it confirms my feelings that I should brake harder than usual this time.
I was extremely skeptical about CMBS when I bought the car, but now I would not turn it off or even change the sensitivity, especially since I know it that CMBS breaking can be cancelled if necessary right off by pressing the gas pedal.

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That's great to know. I hadn't seen that when I looked through the manual online. Thanks.

I’ll have to check my manual myself actually.
It’s true in most cases for sure.
The lane guidance pushing you back in the lane, the soft braking you may not even be noticing.
You can essentially shake them all off by being a bit insistent and it will give up and let you do what you’re trying to do.

Hadn’t seen that about a full hard brake though presumably since the logic is that it’s completely certain you are immediately about to be in a crash and it has to stop right then and there to prevent it. Letting you accelerate out of that scenario seems counterintuitive. But again. I need to reread the manual. So I’m just spitballing.

35,000 miles and I can count the times it's done a WHAT THE HELL stop on one hand. One time was because the streets of Philadelphia suck and the dip was so big the car must have thought I was driving towards a short wall, and it slammed on the brakes and wouldn't go even hitting the accelerator, kind of a freak out. And once was a car turning that I knew was turning but CMBS was thinking I was going to hit it. And only one time did it hit the brake and I actually have no idea why. But that time was just quick jab of the brake and when I hit the accelerator it went. But I've not felt it's overly aggressive and when it does alert me it's usually because I've waited before braking and kinda makes me drive with a bit more space between myself and the vehicle in front.

Also when I first got the car it literally saved me from an accident when the car in front of me stopped in a roundabout for no reason whatsoever. I would have definitely hit him as I was looking to the left to double check that nobody was coming. I'm glad I have it. Mine is a 2017 touring.

2019 Hatchback Touring. I have had the light flash "BRAKE" a few times in the neighborhood but no brakes were applied. Love the car and no problems. Daily commute 60 miles. City and Highway.

If anything, it has made me a better driver. I can't change lanes without using the turn signal or I get the lane departure. But I do like the LKAS. Yes, one could turn it all off. But really for me it has not presented a problem.

I do wonder what would happen when I drive out of lane to avoid debris? Fortunately, that has not happened. Another option on the Touring is auto bright headlights. They seem to be perfect. No override needed and I love them. As with technology nothing is perfect but with the Civic it appears to be close to perfect. No complains so far and 2,500 miles of driving.

Most annoying thing about the false alarms for the collision mitigation is that it'll cancel cruise control which is often in traffic. Never had it apply brake for me.