Tesla US Patent US20260017503A1: 'the system inoperable'

This isn't marketing. It's a legal filing.

US Patent Application 20260017503A1, titled 'Bit-Augmented Arithmetic Convolution', is a patent application filed by Tesla with the USPTO. Patents are public, certified legal documents. What Tesla writes in them is submitted to a government agency as a party statement. It's binding in that sense. Not marketing, not a tweet, not a press release.

Tesla filed two related patent applications alongside this one: US20260017019A1 and US20260017051A1. All three address the same technical challenge: how to run the newer, larger Full Self-Driving models on the older Hardware 3 computer, which wasn't physically designed for that load.

The math trick to squeeze FSD onto old hardware

Technically, the patent describes a method to split 16-bit numbers into two 8-bit pieces, process each piece separately through the neural network accelerators of Hardware 3, and then stitch the results back together. The goal is to emulate the high-precision calculations that AI4 natively supports.

This isn't some optional performance boost. It's a mathematical trick to work around a fundamental hardware limitation. Tesla explicitly describes in the patent that this approach has several serious drawbacks.

Tesla's own words in the patent

In the patent text, Tesla acknowledges:

"such operations can impose latency so as to degrade a user experience"

And, specifically about autonomous driving (this is the critical passage):

"for perception units of an autonomous driving system, the incurred latency can degrade or even render a system inoperable."

'Degrade' and 'inoperable' are Tesla's words, not ours

This isn't a vague caveat. Tesla names two concrete consequences:

1. Degrade: the system performs worse.
2. Inoperable: the system can become unusable.

And the application this is about? 'Perception units of an autonomous driving system', exactly the core function of Full Self-Driving. That's the camera and sensor processing that decides whether a pedestrian is crossing, whether a cyclist is beside the vehicle, or whether a traffic light is red.

Tesla writes in its own patent application that its workaround for HW3 can render the safety-critical part of the system unusable. That's not a warning to competitors. It's Tesla explaining to the USPTO why the invention is non-trivial and why it deserves protection.

This kills one of Tesla's defences

This evidence eliminates one of Tesla's possible defences in one move. In prior correspondence Tesla suggested that FSD is 'still in development' and that software updates will solve the problem. The patent directly refutes that:

• Tesla admits there's a fundamental hardware limitation
• Tesla admits the workaround (the 'math trick') isn't without risk
• Tesla admits the risk affects the most critical part of the system

If Tesla's own patent application says that HW3 can render the system 'inoperable', then Tesla can't, in a Dutch legal procedure, argue that HW3 simply receives 'the latest safety improvements'. Those are irreconcilable positions. One of them must be wrong.

How to verify

The patent is publicly searchable via the USPTO database (patents.google.com or uspto.gov). Electrek published the story in January 2026 and quoted the passages verbatim. For legal proceedings the application is best downloaded directly from the USPTO and, if desired, notarially recorded.