With the latest release of the Tesla app, we went on a deep dive to find what secrets Tesla had hidden in there, and we found one that’s rather interesting. The Cybercab will not just feature steer-by-wire like the Cybertruck, but also true Brake-by-Wire.
Code strings discovered in the app include specific references to “Brakes SW - Brake-by-Wire (Cybercab)”, confirming that Tesla’s latest vehicle will abandon the traditional hydraulic link between the pedal and the calipers.
What is Brake-by-Wire?
In a traditional car, pressing the brake pedal mechanically actuates a master cylinder, which uses hydraulic pressure to force brake fluid through the system and clamp the brake pads against the rotors.
In a brake-by-wire system, there is no direct physical connection between the brake pedal and the brakes themselves. Instead, pressing the pedal sends an electronic signal to a computer, which then commands electric actuators—or a centrally controlled electric brake system—to apply braking force at the wheels.
This mirrors the Steer-by-Wire system on the Cybertruck, in which the steering wheel has no physical linkage connecting it to the wheels.
The Cybercab is currently manually driven, meaning it has pedals that activate the electric signal to brake the vehicle. However, in an autonomous, pedal-less vehicle, this change makes a lot of sense. There’s simply no need for all of these extra parts. This not only reduces failure points in mechanical components but also lowers the cost of producing the vehicle.
Cybercab vs Refreshed Model Y
This discovery highlights another key difference between Tesla’s consumer vehicles and its next-gen Robotaxi.
The Refreshed Model Y features a sophisticated hybrid braking system that uses two master cylinders. The primary cylinder is an electronic cylinder, software-controlled for smooth regen blending and braking on FSD. The secondary cylinder is physical, connected to the actual braking system.
This is what allows Tesla to increase vehicle efficiency with the new braking system in the Model Y. It allows the vehicle to selectively use regenerative braking, even when the user presses the brake pedal. When the driver taps the brakes, the vehicle can decide whether to use the physical brakes, use regenerative braking, or a blend of the two.
In other Tesla vehicles with a single master cylinder, regenerative braking is applied only when the driver lifts their foot off the brake pedal. As soon as the driver taps the brake pedal, the vehicle’s physical brakes kick in.
While the Model Y can and does brake electronically, it still retains a physical mechanical link to the brakes as a fail-safe.
The Cybercab, however, is logically ditching the physical link entirely. Since the production Cybercab will have no pedals, there is no need for a mechanical backup loop for a human driver. Instead, the vehicle will likely rely on redundant power sources and motors to ensure the brakes can always engage, even if one electrical circuit fails.
Why Does This Matter?
We all know the Cybercab won’t have any pedals, so there aren’t any physical controls to brake with. So what’s the big deal?
Moving to full Brake-by-Wire offers three massive advantages for Tesla’s current Model Y robotaxis. By eliminating the brake pedal, vacuum boosters, and a firewall-mounted master cylinder, Tesla can reclaim additional interior space for passenger legroom. In addition, the fully electronic system can seamlessly blend regenerative braking (using the motors) and friction braking (using the discs) to achieve even smoother stops.
But the best part is fewer parts. Fewer hydraulic lines mean less fluid maintenance and fewer points of mechanical failure over the vehicle’s intended service life, which is going to be absolutely key for a Robotaxi.
