We get our first view at hardware 4.0 for the Model Y
Greentheonly/Twitter
In a recent series of fascinating tweets, @greentheonly provided an unprecedented look into the internals of Tesla's new Model Y Hardware 4 or HW4. With his expertise and knowledge, Green shared detailed observations on the HW4's physical structure, board components, and the viability of retrofitting older models, giving the Tesla community much to ponder.
Breaking Down the HW4's Structure
Green's exploration of the HW4's complexities commenced with him acknowledging an "anonymous donor" for providing a chance to look inside Model Y's HW4. The serial numbers and other identifiers were blacked out. Green stated it was done to protect the donor after previous experiences, "Tesla is vengeful like this and went after the guy that did hw2.0 teardown by trying to deny warranty on unrelated repairs. Does not help that this new computer now has a (borderline illegal) 'warranty void if removed' sticker."
Delving into HW4's Core: Circuitry and Components
First up on the dissection table was the computer's physical form factor. According to Green, the HW4's form factor mirrors those of the S/X models, putting to bed any speculation around a potential retrofit to HW3 cars.
Moving deeper into the HW4, Green revealed that the board layout is similar to the HW4 on the Model S. However, as Green termed it, specific components, including the GPU and superior sound hardware, are now missing or depopulated. The use of cheaper non-Error-Correcting Code ram (ECC RAM) also seems to be a cost-cutting measure implemented by Tesla in this version of HW4 on the infotainment system side. Interestingly, this version of HW4 features two additional but depopulated display connectors, hinting at possible a possible second display in the vehicle.
Other distinguishing attributes of HW4 include a reoriented BroadR-Reach ethernet and the addition of a third, depopulated ethernet. Moreover, Green pointed out that the gateway chip has changed, too, with a different model from another vendor now in use. This chip, which was only seen in Chinese-made boards previously, seems to be a standard feature in all Model Y HW4 boards now.
Retrofitting HW3 to HW4: More Than Meets the Eye
The idea of retrofitting HW3 cars with HW4 stirred up quite a debate. According to Green, the concept may sound enticing, but it's not as straightforward as it seems. Modifying the vehicle to accommodate the new coolant pipe locations would be necessary for a retrofit, likely making this option more costly than simply manufacturing a new board in the old form factor.
Uncovering the Hidden Changes
Apart from the apparent changes, Green shared insights into some of the subtle modifications made by Tesla. For instance, the Texas-manufactured Model Ys feature a plastic "firewall" requiring a change in mounting methods for the new HW4. Despite the internal components remaining the same, the different mounting technique necessitates a unique part number for the computer.
The missing camera connectors were for additional cameras, such as a front bumper camera. However, as Green says, the absence of a connector doesn't mean that Tesla won't add them in the future. In fact, if Tesla had no intentions of adding such features, they wouldn't be available on the board at all, instead of just being unpopulated.
Implications for Current and Prospective Tesla Owners
For existing and future Tesla owners, these findings offer a clearer understanding of what to expect from the HW4-equipped Model Ys. Notably, questions still linger about additional cameras and if and when newer models will receive them. The Cybertruck prototype already has a front bumper camera, so it may only be a matter of time.
While it seems that retrofitting HW3 to HW4 may not be feasible due to the cost and complexity involved, Green isn't entirely ruling out the possibility. He believes a different version could theoretically be created for retrofits, although it's unlikely.
Tesla has begun installing a new set of anti-theft measures on some Supercharger cables. This is a two-part process, and includes an exterior-wrap called DyeDefender, as well as engravings on the actual copper of the Supercharger cables themselves.
Superchargers, just like other high-speed electric vehicle charging stations, have been consistently subject to both vandalism and theft. While vandalism is something that can be reduced by increasing policing and security in the area, theft is a different beast to tackle.
Thieves are usually after the copper inside the charging cable - which is densely packed and valuable when taken to a scrap yard. So how is Tesla tackling this?
DyeDefender
First up is a field trial of a product called DyeDefender. You can find this product online to secure ICE catalytic convertors, but the overall premise is fairly simple. A pressurized staining dye is housed inside a stainless steel hose, which is laid overtop or around the object you need to protect - in this case, the Supercharger cable.
The stainless steel cable itself is called CatStrap - and is extremely difficult to cut through. If you do manage to cut through, the dye squirts out, coloring you blue quickly. The dye itself is harmless, but helps to identify potential thieves. Tesla’s Head of Charging - Max de Zegher, confirmed that this is only a trial rollout - instead, Tesla is considering another alternative.
Tesla has begun installing new anti-theft measures on some Supercharger cables, consisting of an exterior wrap called DyeDefender and engravings on the copper wiring inside the cables.
Like other high-speed EV charging stations, Superchargers have been frequent targets of vandalism and theft. While vandalism can often be mitigated through increased security, theft presents a bigger challenge. Thieves primarily target the copper inside the charging cables, which is densely packed and valuable as scrap metal.
DyeDefender
To address this, Tesla is trialing DyeDefender, a theft deterrent system commonly used to protect catalytic converters. It consists of a pressurized staining dye housed within a stainless steel hose called CatStrap, which wraps around the Supercharger cable. The CatStrap is highly resistant to cutting, but if breached, it releases a bright blue dye. While harmless, the dye is difficult to remove, making it easier to identify suspects.
In addition to DyeDefender, Tesla is also engraving the actual copper wiring inside the cables, making stolen material harder to sell since scrapyards often reject marked metals.
Engraved Cables
This alternative is more scalable, more cost effective, and doesn’t impact service operations or the customer experience - and its simply engraving the copper inside the cables. Superchargers cables will state “Property of Tesla” on them - engraved right into the cable from the factory in Buffalo, New York.
Engraved -
Not a Tesla App
Recycling companies and scrap yards will see that the cables belong to Tesla - and won’t accept them. Instead, they’ll reach out to Tesla to inform them that they have received stolen goods. While that may not have an impact immediately - as thieves learn that the copper they steal from Superchargers is worthless and could risk them getting in trouble, they’ll be less likely to go ahead and try.
It is definitely interesting to see Tesla try out some rather unique options to keep Supercharger sites safe and functional. Tesla will likely focus the deployment of DyeDefender in areas that experience continual theft - but again, this is only a trial. The impact of cable engraving will likely take some time, but it’ll pay off in the long run.
Until then, make sure to keep reporting any downed Supercharger sites. You can do that in the Tesla App through Location > Charging >Select Site > Report an Issue. If you have any other neat ideas on how Tesla can stop vandalism and theft, let us know in the comments or in the forums!
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This solution is more scalable, cost-effective, and doesn’t disrupt service operations or the customer experience—it simply involves engraving the copper inside the cables. Supercharger cables will be permanently marked with “Property of Tesla Motors,” engraved directly at the factory in Buffalo, New York.
Recycling companies and scrap yards will immediately recognize that the cables belong to Tesla and refuse to accept them. Instead, they may notify Tesla that they’ve received stolen goods. While this may not have an immediate impact, over time, as thieves realize that stolen Supercharger copper is unsellable and could get them caught, they’ll be less inclined to target them.
It’s interesting to see Tesla experiment with unique ways to protect Supercharger sites. While the company will likely focus on DyeDefender deployments in high-theft areas, this remains a trial phase. The full impact of cable engraving may take time to materialize, but it should prove effective in the long run.
In the meantime, continue reporting any downed Supercharger sites through the Tesla app by navigating to Location > Charging > Select Site > Report an Issue.
If you have any creative ideas on how Tesla can prevent vandalism and theft, share them with us on social media.
Tesla has released software update 2025.2.6, and while minor updates typically focus on bug fixes, this one introduces a major new feature. With this update, Tesla has activated the in-cabin radar, a sensor that has been included in some vehicles for more than three years but remained unused until now.
Why Not Vision?
Unlike vision-based systems, radar can precisely measure object dimensions and even detect movement behind obstacles by bouncing radio waves off surrounding surfaces. This allows for more accurate and reliable measurements of objects that vision may not even be able to see, such as behind the front seats.
What Tesla Announced
Tesla recently highlighted the 4D radar in the new Model Y, explaining how it will improve passenger safety. Tesla executives stated that the radar would be used to properly classify passengers and improve the way airbags deploy.
Tesla went on to say that in a future update, Tesla will use the in-cabin radar to detect any potential passengers left in the vehicles. Since radar can even pick up on heartbeat and breathing patterns, it can provide a much more accurate method of detecting children left in a vehicle. Tesla talked about how the vehicle will send owners a notification via the Tesla app and enable the HVAC system if it detects a passenger in the vehicle. It’ll even call emergency services if needed.
New Feature in Update 2025.2.6
Tesla has officially named this feature in update 2025.2.6, “First-Row Cabin Sensing Update,” which appears to align with the first portion of what Tesla discussed in the new Model Y video.
In the release notes, Tesla describes the update as:
“The first-row cabin sensing system has been updated to use cabin radar, which is now standard in all new 2025 Model Ys. Your Model Y was built pre-equipped with the necessary hardware, allowing Tesla to also bring this technology to your vehicle.”
For now, it appears that Tesla is using the radar to detect and classify passengers in the front seats. This could eventually replace traditional seat sensors, reducing the number of hardware components and lowering production costs.
Tesla plans to expand the feature later this year, bringing rear-seat passenger detection in Q3 2025. While Tesla talked about the feature for the new Model Y, we expect it to be available for all vehicles with the in-cabin radar.
Supported Models
Although Tesla is vague in their release notes, this feature is being added to all Model Ys that include a cabin radar. Tesla started including the cabin radar in 2022, but its availability may vary by region and model. The Model 3 didn’t receive the cabin radar until it was redesigned in 2024, while all Cybertrucks already include it.
The owner’s manual for the redesigned Model S and Model X doesn’t specifically mention the interior radar, although Greentheonly believes the vehicles also include one, so we’ll have to wait to determine whether those vehicles also receive this new feature.
At this time, the feature appears to be only going out to Model Y vehicles, but we expect it to become available on other supported models soon.
We love to see these kinds of updates. Tesla is increasing the safety of existing and new vehicles through a software update while also making them more affordable to own.
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