Forward collision warning without auto pilot

[chyuan]

New owner of MY for less than 10 days so not sure if this is normal.

Twice in the past week when I was driving on the local street without auto pilot, speed < 40mph and with at least more than 2-3 cars distance from the car in front, and all the sudden the forward collision warning would trigger for like a second which freaks me out but all it had happened was probably the car in front slows down slightly where I wouldn't even normally step on the brake and at best just need to let go slightly on gas pedal if I were to drive an ICE card.

So my question is, 1. Is forward collision warning supposed to trigger even without auto pilot (since the setting is under the auto pilot section), and 2. Is this normal that FCW just triggers seemingly randomly?

 

[Tam]

...1. Is forward collision warning supposed to trigger even without auto pilot...

Yes. It's even more important when you autopilot off.

You can manually turn it off if you like.

...Is this normal that FCW just triggers seemingly randomly?...

"randomly" sounds abnormal but since most of the features in Tesla are beta so perhaps this is not abnormal at all.

 

[chyuan]

Yes. It's even more important when you autopilot off.

You can manually turn it off if you like.




"randomly" sounds abnormal but since most of the features in Tesla are beta so perhaps this is not abnormal at all.

By randomly I meant both times when I experienced it they didn’t appear to be much different from how far I’m from the car in front of me or how fast I’m approaching the car so I can’t really tell why the FCW triggered…

For now I changed the setting to “Late” instead of “Medium” in the FCW setting under the auto pilot section will see whether it happened again.

What I’m afraid of is Tesla somehow sees some “phantom” stuff like how other people have discussed it in other threads.

One time I’m stopped before a traffic light and I’m looking at the screen and it suddenly shows a “pedestrian” running in front of me for a second when there is no one there for sure, so it does seem the Tesla vision sometimes gets confused of what it may be seeing?

 

[Tam]

...What I’m afraid of is Tesla somehow sees some “phantom” stuff like how other people have discussed it in other threads...

I think it's difficult to avoid phantom brakes or undesirable deceleration in Tesla. It's beta and the quirks have not been resolved yet. First Tesla blamed the radar then it promised that by getting rid of the radar (from 4/27/2021 in North America for Model 3 and Y) the problems would be solved by pure vision in radarless Tesla cars.

I think Tesla will eventually solve those problems that you mentioned above but the issue is how soon.

 

[MaC122]

I have had it trigger when the car in front of me was turning right off of the road. I did not slow down, nor did I need to, because the car was going to be out of my path before I reached it at my current speed. Tesla thought otherwise.

 

[Daniel L]

I have had it trigger when the car in front of me was turning right off of the road. I did not slow down, nor did I need to, because the car was going to be out of my path before I reached it at my current speed. Tesla thought otherwise.

This is the only time it has happened to me as well. It did not start braking yet, just a warning.

 

[OxBrew]

2X in the first 3 days I had it brake for me; first time after a car in front decided last minute to slam on the brakes and turn into a parking lot. Was on AP, after the car cleared, AP kept on going as normal.

Whole thing was quite normal feeling, not abrupt at all.

Second time was not AP, just cruise control, I got cut off by a truck on the freeway. Hit the brakes slightly, got the gap back to normal.

I have collision avoidance set to early, gap on cruise as long as possible. Still tailgates a bit close, I often back off even farther.

One other time, about day 4 of ownership, on AP at about 28mph the car swerved to avoid a squirrel, moved about 18" to the right. I was going to hit the squirrel for sure.

 

[ZaphodB]

I think it's difficult to avoid phantom brakes or undesirable deceleration in Tesla. It's beta and the quirks have not been resolved yet. First Tesla blamed the radar then it promised that by getting rid of the radar (from 4/27/2021 in North America for Model 3 and Y) the problems would be solved by pure vision in radarless Tesla cars.

I think Tesla will eventually solve those problems that you mentioned above but the issue is how soon.

I have a no-radar Y and still get occasional phantom braking events even with no traffic, no autopilot active, no fsd software installed.

 

[Tam]

I have a no-radar Y and still get occasional phantom braking events even with no traffic, no autopilot active, no fsd software installed.

No doubt that it happens to you currently.

Even when you turn off all Autopilot/FSD for Tesla cars produced since 10/2016, functions that are speed-related like Forward Collision feature, Automatic Emergency Braking, phantom brakes, false slowdowns... still run on the latest firmware.

However, there's a promise to fix it by getting rid of the radar. A promise is a promise. The question is how soon:

https://twitter.com/x/status/1392429457038667777

 

[RowdyMY]

Had an interesting "control group" experience with this just this week.

My spouse regularly gets a random FCW in her M3SR+ at the same intersection on her way to work everyday. I have a MY but had a M3 Loaner from Tesla that had 12k on it for a week (i.e. the loaner wasn't a brand new build like yours). I was driving her up to drop off and I had the same exact FCW at the same intersection in the loaner.

No lead cars for us when it happened to me. She normally drives it at ~7-8 in the morning and this was at 2:30pm so her hypothesis that it was a shadow thing was ruled out.

Her M3SR software is 32.21.

 

[Ruby's Driver]

I had a Forward Collision Warning today when a truck decided to make a sudden turn. I didn't mind the warning but it trashed my driving score for the day! I had left plenty of following distance and lifted off the accelerator as soon as I saw it's brake lights. At that instant the ACW went off. The car came to a stop more than a car length from the truck and I never touched the brake!

I have my FCW set to "Early". If I set it to "Late" or "OFF" I probably would have not gotten the warning. Does that mean it would not have counted on my driving score? Can having FCW set to "Early" have a negative impact on the Driving Score?

 

[Brendazzle]

I had the same thing my first couple weeks. Changed it to “Late” and all good now.