Tesla’s FSD continues to expand and learn, and V13 won’t be any slouch on this. V12 implemented end-to-end AI, and V13 brings a host of new features to help it reach feature completeness.
Today, FSD relies almost entirely upon visual data acquired from the vehicle’s cameras. Of course, it does pull information from other sensors, but the primary input is vision. While Tesla previously used radar in its vehicles and still ships the Models S and X with deactivated HD Radars, it relies on vision to guide its decision-making.
But that’s all changing—a revised version of V13 will bring audio-based decision-making to FSD for the first time. FSD is famously designed to work like a human driver—it relies on vision—but now it’ll also begin relying upon audio—both as an input… and an output.
We touched upon these items in our article on FSD V13, but it's time to really dig into them.
Listening for Emergency Vehicles
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FSD will soon be able to detect emergency vehicles by analyzing the sounds it hears. Interestingly, this will be done through the internal microphone—the same one used for voice commands. That’s because sirens are loud—loud enough for humans (and microphones) to hear them inside a moving car.
This will enable FSD to identify the distinct sounds of an approaching siren - helping to ensure that FSD detects emergency vehicles earlier and takes the correct maneuvers to move out of the way and safely pull over.
In addition, by analyzing the actual sound of the incoming siren, FSD should also be able to make a reasonable determination about whether the siren is approaching or just echoing off the city streets using the Doppler effect and some fairly simple math.
With the release of FSD V13.2 to early access testers and now FSD 12.5.6.4, Tesla has added a new item to the release notes that lets drivers opt-in to sharing audio data. For users who opt-in to sharing this data, Tesla will now receive 10-second audio clips in certain situations. Tesla will listen for certain sounds and then send this data back to Tesla for further analysis. This will help them improve certain sound detections.
In the release notes, Tesla specifically mentions detecting emergency vehicles by sound, but it seems that it will also be used for other things, such as listening for other vehicles honking or potentially someone yelling at the vehicle. These additional capabilities will help FSD navigate a world made for humans, which couldn’t be done with vision alone.
FSD Will Honk
So we’ve covered inputs… what about outputs? Ashok Elluswamy, Tesla’s VP of AI, mentioned that FSD will gain the ability to honk. That means FSD will be able to provide an audio cue to other vehicles - just like a real, human driver would. Whether that’s someone cutting FSD off, or someone dozing off at a traffic light, FSD gaining the ability to honk will be extremely valuable - it’s the first ability FSD will have to communicate with the outside world and with other drivers.
Humans have developed different types of honks, such as short, friendly taps of the horn or louder, longer horn presses for emergency situations. It’ll be interesting to see if Tesla also implements different types of honks as well.
This is one of the key steps to humanizing FSD - one of the final puzzle pieces. This is expected to be the final set of inputs necessary for FSD to be able to drive like a human, and it’s exciting to see Tesla get so close with just vision.
FSD will soon be able to see, hear, and honk. Let’s just hope Tesla’s initial implementation for honking is better than Waymo’s (video below of Waymo vehicles honking repeatedly at 4 am).
Imagine being woken up at 4 a.m. by cars honking at each other. That's what some San Francisco residents have been dealing with for weeks, as the Waymos can be heard in this video honking and blinking headlights in a parking lot outside of their condo. https://t.co/2cVmDfUk4ipic.twitter.com/pkxNTT5vXd
Following the latest meeting of the United Nations Economic Commission for Europe (UNECE), which decides safety regulations for vehicles, it seems that Tesla will be facing further delays and regulatory hurdles in Europe. The Telegraph in the UK reported on this story yesterday following the conclusion of UNECE discussions.
Tesla has been waiting for regulatory approval in Europe, which would pave the way for wider FSD deployment across the EU and other countries that adhere to UNECE regulations.
Regulatory Shut Down
The latest round of delays stems from efforts by the UK, Norway, Sweden, and the Netherlands to push for additional testing and trials of autonomous systems. Progress toward approving vehicle autonomy in Europe has faced repeated setbacks, and this latest hurdle casts further doubt on the prospects for European customers awaiting FSD.
Regulatory changes that initially seemed on track to ease restrictions were stalled in September 2024 when the UK’s Department for Transport raised concerns, stating:
“While [a driver assistance system] may help reduce collisions, it may also introduce new safety risks.”
This perspective sounds like it comes from someone who has never actually used an advanced driver assist system—whether from Tesla or its competitors.
The UNECE, which oversees vehicle regulations in Europe, is set to meet again in June and November. However, based on the agenda from the most recent session, autonomy does not appear to be on the docket for the June meeting.
What This Means for FSD in Europe
Simply put, FSD isn’t coming to Europe anytime soon. While Tesla has some potential workarounds, none are ideal.
One option would be for Tesla to pursue regulatory exemptions on a nation-by-nation basis—requesting approval for each and every FSD feature separately. That means filing exemptions for lane changes, left and right turns, highway exits, and countless other functions. The bureaucratic process would be exhausting, requiring approval from each country individually.
Alternatively, Tesla could release a heavily restricted version of FSD that complies with current UNECE regulations. However, this would likely make the system impractical, as drivers would have to manually confirm every single action—down to something as simple as adjusting speed—using a physical button press.
For now, Europe’s regulatory framework remains a major roadblock to autonomy. Unless there’s a significant shift in policy, it’s unlikely that FSD will launch in Europe in 2025 as planned.
Tesla recently started rolling out an update that enabled the cabin radar in recent Model Ys and added support for first-row cabin sensing. This functionality not only lets Tesla replace the seat occupancy sensors in the front seats but also gives them a better idea of the size of the passengers — critical information when an accident occurs.
However, Tesla has now revealed that it won’t just be recent versions of Model Y that will receive these updates. Other recent vehicles also have a dormant in-cabin radar that will be activated in a future update.
Child Presence Detection
This front-row occupant sensing is only half of the update. Tesla also plans to add support to the rear seats that will let it detect occupants left in the vehicle. In a post on X, Tesla stated that at least 37 children die per year from heatstroke, just in the United States, according to the NHTSA. Tesla’s cabin radar will help reduce the number of deaths by detecting children left in the vehicle and alerting the owner or turning on the HVAC system.
The new radar has several safety-focused features, and they’re all designed to help protect someone left behind in a vehicle. First up - the radar will detect and classify passenger sizes to determine which airbags to deploy dynamically, helping to reduce injuries from shorter individuals sitting up front.
Additionally, the radar can differentiate an adult from a child or baby - and automatically and dynamically make the necessary safety adjustments on the fly. Tesla will also be able to detect heart rate and breathing through the radar - and has a series of safety steps it can take from here.
If a child or baby is detected being left behind in the vehicle, the Tesla app will immediately notify you and turn on the HVAC system to ensure their safety. In the case of an emergency, the vehicle will automatically call emergency services and report its location.
As a reminder, while Tesla vehicles outside of the United States support eCall, vehicles within the US cannot call 911 unless a phone is connected to the vehicle via Bluetooth. We hope that Tesla looks to add similar capabilities in North America to improve safety capabilities.
Supported Models
Although the cabin radar has only been activated in Model Ys produced in the last couple of years, Tesla said in their post on X that the radar is also available in recent Model 3s and the Cybertruck.
We did a little digging and confirmed that the part numbers for the cabin radar are the same for the 2024+ Model Y, 2024+ (new) Model 3, and the Cybertruck. So, these vehicles should also receive the latest cabin radar features.
Although the 2023 Model Y features a different part number, 2022 and 2023 Model Ys have also been receiving the front-row cabin sensing feature in Tesla’s 2025.2.6 update, but it is less clear whether they’ll receive the rear seats update later this year. The Model S and Model X also include a cabin radar, but the part number also differs from the cabin radar for the 2024 Model 3 and Model Y.
While the new Model Y isn’t available to check against on Tesla’s Electronic Parts Catalog, it looks like Tesla has been shipping the new 4D cabin radar in at least the 2024+ versions of their Model 3, Model Y and Cybertruck.
We expect rear-seat sensing to arrive on vehicles with the latest cabin radar later this year, while it’s unclear whether the other vehicles with the older cabin radar will receive it.
Tesla mentioned that rear-seat support will arrive in Q3 2025 for the refreshed Model Y. Based on the different interior sizes and spaces, sensor calibration and testing for other models may come slightly later.
