Without fanfare, Tesla has introduced their most refined self-driving computer, Hardware 4.0 (HW4), into the Model Y lineup. It's a surprising move, as it was believed HW4 would roll out with the Model Y redesign. This strategic decision, executed in Tesla’s unique, understated style, follows the quiet integration of HW4 into the luxury Model S and Model X models earlier this year.
This shift came to light thanks to one of our sources, who has provided accurate information in the past. Tesla owner Zack (@BLKMDL3) has now identified multiple Model Y units equipped with fresh hardware at his local delivery center. The distinctive upgraded side repeater and forward-facing cameras indicate HW4 were observed in both Long Range and Performance variants of the Model Y.
Transitioning to the New Standard
Notwithstanding these exciting sightings, numerous Model Ys with the previous hardware was still found at the delivery site. As is customary with Tesla’s approach to hardware rollouts, the full switch to HW4 across all Model Ys will take some time as Tesla factories incorporate these changes.
Source code information connected to a recently manufactured Model Y also confirmed the presence of HW4, designated as "AP HW4". Interestingly, this phased implementation might lead to disparities among Model Y units depending on their manufacturing origin. For instance, those made in China, where no HW4 incorporation has been reported yet, might cause Canadian customers to miss out on the HW4 upgrade.
HW4: Paving the Way for Enhanced Autonomy
Tesla’s HW4 represents the company’s commitment to refine its vision-based self-driving system further, shifting from the previous reliance on a combination of vision and radar sensors. It plays a pivotal role in Tesla’s bold objective to master Full Self-Driving (FSD) by year-end.
Nonetheless, it's worth noting that certain functionalities were not instantly available during the early stages of HW4 deployment. This factor likely played a role in Tesla's decision to delay its introduction of the Model Y. As Tesla continues perfecting HW4, further enhancements are anticipated, including improved handling of complicated maneuvers, such as unprotected turns.
Tesla has introduced hardware 4.0 for the Model Y
BLKMDL3/Twitter
The Hardware Evolution: Comparing HW4 and HW3
Insightful images shared by the Tesla community have provided a comparative look between HW4 and its predecessor, Hardware 3.0 (HW3). Of note, the side repeater cameras on the Model Y with HW4 have noticeably larger lens housings and a wider field of view. This departs from early anticipations, which projected HW4 would introduce additional cameras. Instead, the updated hardware seems to enhance the existing camera system.
What Lies Ahead
The introduction of HW4 into the Model Y marks a remarkable stride in Tesla's commitment to perfecting Full Self-Driving technology. As Tesla continues to develop and refine HW4, it's exciting to envision the transformative potential this holds for the automotive landscape.
While Tesla CEO Elon Musk’s ambitious vision of a Robotaxi fleet may still be some way off, the integration of HW4 in the Model Y undeniably represents a key milestone in that journey. As this revolutionary technology evolves, the world eagerly awaits the exciting advancements it promises to bring to the autonomous driving experience.
Tesla’s been on a roll with Supercharger improvements lately, from the 325kW charging update for the Cybertruck, to 500kW with V4 Superchargers coming next year. While those improvements have been limited to the Cybertruck, Tesla didn’t put all their focus on their new flagship vehicle, but looked at their more affordable vehicles as well.
LFP Battery Heating
Tesla’s Superchargers can now heat LFP Batteries - those that are in the Model 3 and Model Y Rear Wheel Drive variants. This applies to Long Range and Standard Range models, which saw a limited run. This is another update included as part of the 2024 Tesla Holiday Update - which really arrived with a lot of unannounced new features and capabilities.
The change is pretty interesting - Superchargers of the V3 and V4 variety can now pre-heat batteries for Model 3 and Model Y vehicles equipped with LFP battery packs. That means those vehicles are able to get back on the road faster when it's extremely cold. Of course, Tesla still advises you to precondition before you arrive, saving drivers time and money.
Max de Zegher, Tesla’s Director of Charging, also commented on the new feature. Essentially, Tesla is inducing an AC (alternating) ripple current through the battery to warm it up. Keep in mind that Superchargers are DC charging. That means it is possible to get a cold-soaked LFP vehicle on the road 4x faster than before, assuming that it didn’t precondition at all and that it is in the worst-case scenario (below 0ºF).
In essence, Tesla is using some engineering magic to turn the circuits inside the LFP battery into an electric heater - and powering that heater through the Supercharger. An AC ripple current is a small oscillation in the DC charging current that generates heat through electrical resistance, warming up the battery. Those ripples are a byproduct of converting AC to DC and back - so Tesla is using the onboard charger to induce those ripples to warm up the battery. Definitely an innovative technique that’s really only possible with the versatility of the NACS connector.
We’re hoping Tesla can implement this across their full lineup of vehicles, but we’ll have to wait and see how it is trialed across LFP vehicles first and if it is even possible on vehicles with 2170 or 4680 battery packs.
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.
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