Auto Lane Change unreliable in FSD v12.3.6

[EVRider-FL]

I’ve been on a road trip in my 2023 Model S (HW4). I’ve used FSD for almost all of my driving, both on and off the highway. I started the trip with 2024.3.25, then updated to 2024.14.9 during the trip. Both versions have FSD v12.3.6. I know that on the highway, the car uses FSD v11.

One annoying issue that occurred frequently throughout the trip: when I initiated a lane change using the turn signal button, the car would not change lanes. The turn signal would come on, but the blue line showing the car’s path didn’t curve into the target lane, and I had to eventually disengage FSD to change lanes. This happened mostly on the highway, and most often when changing lanes to the right. It seemed to happen more when there were no cars ahead of me, but it did happen with more traffic too. In some cases it seemed I could force the lane change by turning the wheel slightly (without disengaging), but not always. I would estimate that this happened with 40% of my lane changes to the right, and was responsible for 95% of my FSD disengagements. I reported the issue many times using the voice recording that you get prompted for, but I stopped doing that after a while.

I did a road trip in the same car last fall, using FSD v11 (I don’t remember which specific version). Auto lane changes sometimes failed with that version too, but not nearly as often as with the current version. In most other respects, FSD v12.3.6 was far better than the previous version, and I was able to use it pretty much everywhere. The only places I didn’t use it was in residential communities with narrow roads and low speed limits, because the auto speed offset feature would allow the car to go too fast.

 

[AceG8tr]

Exactly my experience as well.

 

[PCMc]

I likely have a very similar vintage of MS LR and same software version history, running FSD 12.3.6 since end of April. Just did about 650 interstate miles running exclusively on FSD yesterday. A couple things from my observations.

FSD in general doesn't like being in the right lane, especially if the FSD profile on anything other than chill. If you make the effort to toggle the minimal lane chance feature then it is more willing to stay in right lane if you want, but you have to toggle that each drive as it won't stick.

The other thing are road features that can be perceived incorrectly as a solid line. Best example are the cases where they used a tar like filler in cracks between lanes. Vision system seems to perceive these as solid do not cross lane lines and will not do an auto lane change across them.

And I totally agree about the auto speed offset feature in residential areas. Tends to go crazy fast in many residential situations in my experience.

 

[WhyLR]

2024 MY, used FSD from San Francisco to San Jose, mostly four lane freeway. Set to Chill and no Auto Max. Everything worked fine except when approaching a slow vehicle. The FSD seems to just slow down which I sort of expect in Chill. This being 4 AM, I wasn't about to follow a slower vehicle. I signal a lane change and FSD disengaged. This happened all the time I signaled. Is there another way to approach this?

 

[EVRider-FL]

2024 MY, used FSD from San Francisco to San Jose, mostly four lane freeway. Set to Chill and no Auto Max. Everything worked fine except when approaching a slow vehicle. The FSD seems to just slow down which I sort of expect in Chill. This being 4 AM, I wasn't about to follow a slower vehicle. I signal a lane change and FSD disengaged. This happened all the time I signaled. Is there another way to approach this?

I haven’t experienced FSD disengaging itself when requesting a lane change. Which build do you have?

 

[WhyLR]

2024.14.9. I don't use FSD much. I didn't like the speed it uses and the frequent lane changes. Maybe I'll just not use Auto Max next time.

 

[KArnold]

Everything worked fine except when approaching a slow vehicle. The FSD seems to just slow down

Are you sure "minimal lane changes" was not enabled?

I signal a lane change and FSD disengaged. This happened all the time I signaled

I've not seen this either. Maybe screen shot your FSD settings screen?

 

[phxazcraig]

I use FSD a lot, and I am subscribed to it. An annoying issue for me, in Phoenix Arizona, is HOV lanes. Unlike California, Phoenix HOV lanes have no designated in/out areas. You can get into or out of the HOV lane at any point. But the lanes are marked with a single, wide white line, and FSD simply will not cross over it. To get into the HOV lane, I have to disengage FSD, change lanes and re-engage. Same to get out of the HOV lane. Do your highway failures involve crossing a wide lane line?

And a VERY annoying thing for me is when FSD ignores my turn signal inputs and overrules me. If I put on the signal, it's for a good reason, and I want my car to obey that over almost anything. Usually I'm fighting poor lane selection and trying to get into or out of a turn lane, or just pass slower cars.

It's my strong impression that chill, normal and assertive are not implemented in any way for FSD 12. I can't point to a single thing that is different on the road when you change this setting. I think for now these are just dummy menu entries.

 

[cbdream99]

I have similar experience, it works most of the time, but there are quite a few times, it is either too slow, ignore the request, and then sometimes hesitate - slightly turn towards other lane, swerve back and then complete the switch.

There are times when I am in the left lane on the highway during stop and go traffic, whenever it sees a gap to the express lane, it will dash over without signal thinking that is a faster lane. I don't think FSD knows that and that lane is a reversible express lane.

For solid white line, I have seen both inconsistent behavior, sometimes it won't cross it, but if it really needs to cross it, like about to miss a turn, then it will cross it. Elon mentioned 12.5 will finally merge both stack together.

 

[EVRider-FL]

I use FSD a lot, and I am subscribed to it. An annoying issue for me, in Phoenix Arizona, is HOV lanes. Unlike California, Phoenix HOV lanes have no designated in/out areas. You can get into or out of the HOV lane at any point. But the lanes are marked with a single, wide white line, and FSD simply will not cross over it. To get into the HOV lane, I have to disengage FSD, change lanes and re-engage. Same to get out of the HOV lane. Do your highway failures involve crossing a wide lane line?

In my experience, FSD/EAP has always had problems entering/exiting HOV lanes, but that isn’t the issue I was writing about in my OP.

Here on the East coast, on I-95 in any case, HOV lanes are separated from the others with a double dashed lane marker, which you’re allowed to cross anywhere (unlike express lane markers, which are different). Sometimes I can enter/exit the HOV lane without incident; other times the car will start to change lanes but then abort and ask me to take the wheel. I think it’s the distance between the double markers that confuses the car. I’ve also noticed the driver visualization in FSD v12.3.6 alternates between solid and dashed lines when displaying the HOV lane markers.

 

[ewoodrick]

I’ve been on a road trip in my 2023 Model S (HW4). I’ve used FSD for almost all of my driving, both on and off the highway. I started the trip with 2024.3.25, then updated to 2024.14.9 during the trip. Both versions have FSD v12.3.6. I know that on the highway, the car uses FSD v11.

One annoying issue that occurred frequently throughout the trip: when I initiated a lane change using the turn signal button, the car would not change lanes. The turn signal would come on, but the blue line showing the car’s path didn’t curve into the target lane, and I had to eventually disengage FSD to change lanes. This happened mostly on the highway, and most often when changing lanes to the right. It seemed to happen more when there were no cars ahead of me, but it did happen with more traffic too. In some cases it seemed I could force the lane change by turning the wheel slightly (without disengaging), but not always. I would estimate that this happened with 40% of my lane changes to the right, and was responsible for 95% of my FSD disengagements. I reported the issue many times using the voice recording that you get prompted for, but I stopped doing that after a while.

I did a road trip in the same car last fall, using FSD v11 (I don’t remember which specific version). Auto lane changes sometimes failed with that version too, but not nearly as often as with the current version. In most other respects, FSD v12.3.6 was far better than the previous version, and I was able to use it pretty much everywhere. The only places I didn’t use it was in residential communities with narrow roads and low speed limits, because the auto speed offset feature would allow the car to go too fast.

I believe that if you look, you may see that lane changes have settings. And I suspect that you are in the mode that you have to provide a little torque to the wheel to confirm the lane change. It's really easy to forget to do it.
Also, when it happens, I've seen that all you need to do is turn the turn signal off and then back on again, but don't forget about the torque.

Afte driving a ton of miles torque becomes so natural that it is easy to forget.

 

[EVRider-FL]

I believe that if you look, you may see that lane changes have settings. And I suspect that you are in the mode that you have to provide a little torque to the wheel to confirm the lane change. It's really easy to forget to do it.
Also, when it happens, I've seen that all you need to do is turn the turn signal off and then back on again, but don't forget about the torque.

Afte driving a ton of miles torque becomes so natural that it is easy to forget.

The lane change confirmation setting you’re talking about applies to Navigate on Autopilot, not FSD, and it only applies to lane changes that NoA wants to make, not the ones you initiate. This is something else.

 

[garydoe]

I’ve been on a road trip in my 2023 Model S (HW4). I’ve used FSD for almost all of my driving, both on and off the highway. I started the trip with 2024.3.25, then updated to 2024.14.9 during the trip. Both versions have FSD v12.3.6. I know that on the highway, the car uses FSD v11.

One annoying issue that occurred frequently throughout the trip: when I initiated a lane change using the turn signal button, the car would not change lanes. The turn signal would come on, but the blue line showing the car’s path didn’t curve into the target lane, and I had to eventually disengage FSD to change lanes. This happened mostly on the highway, and most often when changing lanes to the right. It seemed to happen more when there were no cars ahead of me, but it did happen with more traffic too. In some cases it seemed I could force the lane change by turning the wheel slightly (without disengaging), but not always. I would estimate that this happened with 40% of my lane changes to the right, and was responsible for 95% of my FSD disengagements. I reported the issue many times using the voice recording that you get prompted for, but I stopped doing that after a while.

I did a road trip in the same car last fall, using FSD v11 (I don’t remember which specific version). Auto lane changes sometimes failed with that version too, but not nearly as often as with the current version. In most other respects, FSD v12.3.6 was far better than the previous version, and I was able to use it pretty much everywhere. The only places I didn’t use it was in residential communities with narrow roads and low speed limits, because the auto speed offset feature would allow the car to go too fast.

I've had experience with both HW3 and HW4 and I noticed that HW4 reacts less decisively at times. Maybe the HW3 emulation has issues. HW3, though not perfect, seems better overall, with 12.3.6. 12.5 sounds like the reverse has occurred.

I look at EV's, renewable energy and sustainability as a new way of life.
I've been reading what some of my ancestors had to face in Alberta Canada early on.
I don't mind being a Pioneer, if that's what it is, as we move into the future.
Tesla is playing a big part in that future.