Tesla is improving its phone key with ultra-wideband support
Maxim
In Tesla update 2024.2.3, Tesla is rolling out support for ultra-wideband, a wireless protocol that will drastically improve how Tesla phone keys work.
Ultra-wideband (UWB) requires hardware support on the user's phone and the vehicle, so only some of the most recent models will be supported.
What is Ultra-Wide
Ultra-wideband is similar to Bluetooth in that it uses short-range radio waves to enable devices to communicate, although it’s a separate protocol all together. It uses less energy than Bluetooth while providing high-precision location tracking beyond what can be achieved with Bluetooth. The technology is often used to accurately locate devices and determine the precise distance between multiple UWB devices.
Improved Phone Keys
Tesla phone keys are fantastic and give you a way to lock and unlock your vehicle without having to carry a key. They also let you share temporary or permanent keys with others without ever having to hand something over physically. It's one of the ways Tesla can now offer self-serve demo drives without any staff on hand.
While phone keys are great and work reliably most of the time, occasionally the car doesn't recognize that the phone is nearby, requiring you to take out your phone and unlock it or even open the Tesla app before it recognizes that the phone is nearby.
The addition of support for ultra-wideband should solve these issues almost completely by precisely knowing where the phone is in relation to the vehicle. UWB support is also expected to improve other features that rely on knowing your phone’s location, such as selecting the correct driver profile depending on which phone key is closest to the driver’s side.
Enabling UWB Phone Key
The new phone key won’t work out of the box. To use the improved UWB phone key, you’ll need to set it up in the Tesla app. The app will prompt you to “Upgrade Your Phone Key,” and you’ll then need to grant the app access to UWB, which the iPhones call Nearby Interactions. You can remove or check on whether the app has access at any time by navigating to iPhone Settings > Privacy & Security > Nearby Interactions.
Release Notes
Tesla states that its new feature "Ultra-Wideband Phone Key" will improve your phone key due to greater accuracy and better responsibleness.
The release notes read:
"Ultrawide band (UWB) technology is now available for Phone Key. So your vehicle and Phone Key can communicate with greater accuracy to more responsively lock, unlock, and open Automatic Doors.”
“In the Tesla app, choose Phone Key > Upgrade and follow the instructions. After setup, keep your iPhone Settings for Nearby Interactions on for Tesla. Requires iPhone 11+ and Tesla app 4.29.5+."
Cars Supported
Since ultra-wideband requires specific hardware, it can’t be added in a software update unless the hardware is already in the vehicle. Only some of the latest Tesla vehicles appear to support the new wireless protocol.
We have confirmed that the new Model 3 is supported, as well as the 2023 Model X. All refreshed Model S and Model X vehicles include the new UWB frequencies in the certificate of conformity and are likely to receive this feature, but it doesn’t appear to be going out to all new S/X models yet. The Cybertruck is expected to be supported as well.
The first-gen Model 3 and current Model Y unfortunately do not have UWB support.
Phones Support
In addition to the vehicle having support for UWB, the phone must also support it. All models since the iPhone 11 have included support for ultra-wideband. This spans across all models and sizes.
While some Android phones also include UWB hardware, Tesla is launching support for the iPhone first, but we can expect supported Android phones running Android 13 or later to be added at some point in the future as well.
On the Android side, the Pixel 6 and above have support for UWB on the Pro models, while the Galaxy S series phones support the protocol since the S21, but only on the Plus and Ultra models. The Galaxy Z Fold 2 and above also include support as well as other flagship Android phones.
Tesla App Support
Tesla started adding support for ultra-wideband back in July 2023 when Tesla updated their app to v4.23.5 and included references to ultra-wideband. Tesla says that you’ll require the latest Tesla app, v4.29.5 or higher to use the new feature.
Ultra wide-band will bring greater accuracy and reliability to Tesla's phone keys. The phone key is already great and the only thing holding it back is its ability to work reliably 100% of the time, but it looks like that is about to be fixed if you own a new Tesla model.
Tesla launched two FSD updates simultaneously on Saturday night, and what’s most interesting is that they arrived on the same software version. We’ll dig into that a little later, but for now, there’s good news for everyone. For Hardware 3 owners, FSD V12.6.1 is launching to all vehicles, including the Model 3 and Model Y. For AI4 owners, FSD V13.2.4 is launching, starting with the Cybertruck.
FSD V13.2.4
A new V13 build is now rolling out to the Cybertruck and is expected to arrive for the rest of the AI4 fleet soon. However, this build seems to be focused on bug fixes. There are no changes to the release notes for the Cybertruck with this release, and it’s unlikely to feature any changes when it arrives on other vehicles.
FSD V12.6.1 builds upon V12.6, which is the latest FSD version for HW3 vehicles. While FSD V12.6 was only released for the redesigned Model S and Model X with HW3, FSD V12.6.1 is adding support for the Model 3 and Model Y.
While this is only a bug-fix release for users coming from FSD V12.6, it includes massive improvements for anyone coming from an older FSD version. Two of the biggest changes are the new end-to-end highway stack that now utilizes FSD V12 for highway driving and a redesigned controller that allows FSD to drive “V13” smooth.
It also adds speed profiles, earlier lane changes, and more. You can read our in-depth look at all the changes in FSD V12.6.
Same Update, Multiple FSD Builds
What’s interesting about this software version is that it “includes" two FSD updates, V12.6.1 for HW3 and V13.2.4 for HW4 vehicles. While this is interesting, it’s less special when you understand what’s happening under the hood.
The vehicle’s firmware and Autopilot firmware are actually completely separate. While a vehicle downloading a firmware update may look like a singular process, it’s actually performing several functions during this period. First, it downloads the vehicle’s firmware. Upon unpacking the update, it’s instructed which Autopilot/FSD firmware should be downloaded.
While the FSD firmware is separate, the vehicle can’t download any FSD update. The FSD version is hard-coded in the vehicle’s firmware that was just downloaded. This helps Tesla keep the infotainment and Autopilot firmware tightly coupled, leading to fewer issues.
What we’re seeing here is that HW3 vehicles are being told to download one FSD version, while HW4 vehicles are being told to download a different version.
While this is the first time Tesla has had two FSD versions tied to the same vehicle software version, the process hasn’t actually changed, and what we’re seeing won’t lead to faster FSD updates or the ability to download FSD separately. What we’re seeing is the direct result of the divergence of HW3 and HW4.
While HW3/4 remained basically on the same FSD version until recently, it is now necessary to deploy different versions for the two platforms. We expect this to be the norm going forward, where HW3 will be on a much different version of FSD than HW4. While each update may not include two different FSD versions going forward, we may see it occasionally, depending on which features Autopilot is dependent on.
Thanks to Greentheonly for helping us understand what happened with this release and for the insight into Tesla’s processes.
At the 2025 Consumer Electronics Show, Nvidia showed off its new consumer graphics cards, home-scale compute machines, and commercial AI offerings. One of these offerings included the new Nvidia Cosmos training system.
Nvidia is a close partner of Tesla - in fact, they produce and supply the GPUs that Tesla uses to train FSD - the H100s and soon-to-be H200s, located at the new Cortex Supercomputing Cluster at Giga Texas. Nvidia will also challenge Tesla’s lead in developing and deploying synthetic training data for an autonomous driving system - something Tesla is already doing.
However, this is far more important for other manufacturers. We’re going to take a look at what Nvidia is offering and how it compares to what Tesla is already doing. We’ve done a few deep dives into how Tesla’s FSD works, how Tesla streamlines FSD, and, more recently, how they optimize FSD. If you want to get familiar with a bit of the lingo and the background knowledge, we recommend reading those articles before continuing, but we’ll do our best to explain how all this synthetic data works.
Nvidia Cosmos
Nvidia’s Cosmos is a generative AI model created to accelerate the development of physical AI systems, including robots and autonomous vehicles. Remember - Tesla’s FSD is also the same software that powers their humanoid robot, Optimus. Nvidia is aiming to tackle physical, real-world deployments of AI anywhere from your home, your street, or your workplace, just like Tesla.
Cosmos is a physics-aware engine that learns from real-world video and builds simulated video inputs. It tokenizes data to help AI systems learn quicker, all based on the video that is input into the system. Sound familiar? That’s exactly how FSD learns as well.
Cosmos also has the capability to do sensor-fused simulations. That means it can take multiple input sources - video, LiDAR, audio, or whatever else the user intends, and fuse them together into a single-world simulation for your AI model to learn from. This helps train, test, and validate autonomous vehicle behavior in a safe, synthetic format while also providing a massive breadth of data.
Data Scaling
Of course, Cosmos itself still requires video input - the more video you feed it, the more simulations it can generate and run. Data scaling is a necessity for AI applications, as you’ll need to feed it an infinite amount of data to build an infinite amount of scenarios for it to train itself on.
Synthetic data also has a problem - is it real? Can it predict real-world situations? In early 2024, Elon Musk commented on this problem, noting that data scales infinitely both in the real world and in simulated data. A better way to gather testing data is through real-world data. After all, no AI can predict the real world just yet - in fact, that’s an excellent quantum computing problem that the brightest minds are working on.
Yun-Ta Tsai, an engineer at Tesla’s AI team, also mentioned that writing code or generating scenarios doesn’t cover what even the wildest AI hallucinations might come up with. There are lots of optical phenomena and real-world situations that don’t necessarily make sense in the rigid training sets that AI would develop, so real-world data is absolutely essential to build a system that can actually train a useful real-world AI.
Tesla has billions of miles of real-world video that can be used for training, according to Tesla’s Social Media Team Lead Viv. This much data is essential because even today, FSD encounters “edge cases” that can confuse it, slow it down, or render it incapable of continuing, throwing up the dreaded red hands telling the user to take over.
Cosmos was trained on approximately 20 million hours of footage, including human activities like walking and manipulating objects. On the other hand, Tesla’s fleet gathers approximately 2,380 recorded minutes of real-world video per minute. Every 140 hours - just shy of 6 days - Tesla’s fleet gathers 20 million hours of footage. That was a little bit of back-of-the-napkin math, calculated at 60 mph as the average speed.
Generative Worlds
Both Tesla’s FSD and Nvidia’s Cosmos can generate highly realistic, physics-based worlds. These worlds are life-like environments and simulate the movement of people and traffic and the real-life position of obstacles and objects, including curbs, fences, buildings, and other objects.
Tesla uses a combination of real-world data and synthetic data, but the combination of data is heavily weighted to real-world data. Meanwhile, companies who use Cosmos will be weighting their data heavily towards synthetically created situations, drastically limiting what kind of cases they may see in their training datasets.
As such, while generative worlds may be useful to validate an AI quickly, we would argue that these worlds aren’t as useful as real-world data to do the training of an AI.
Overall, Cosmos is an exciting step - others are clearly following in Tesla’s footsteps, but they’re extremely far behind in real-world data. Tesla has built a massive first-mover advantage in AI and autonomy, and others are now playing catch-up.
We’re excited to see how Tesla’s future deployment of its Dojo Supercomputer for Data Labelling adds to its pre-existing lead, and how Cortex will be able to expand, as well as what competitors are going to be bringing to the table. After all, competition breeds innovation - and that’s how Tesla innovated in the EV space to begin with.
