If you notice the EPS (Electric Power Steering) has a CAN (Controller Area Network) bus connection.
The CAN bus is a network over which up to 70 ECU (Electronic Control Units) can communicate with each other.
Data such as speed, RPM, emissions related sensors, safety etc. is/are shared.
Modern cars and trucks have an OBD-2 connection for diagnostics. OBD-2 connects to the CAN bus.
Why do manufacturers have a design where the EPS is connected to the CAN bus connection?
Primarily for speed and safety.
At 80 MPH you don't need a steering system that feels too responsive "whippy".
At 10 MPH you don't need a steering system that feels like an original 50's AD with super wide tires.
For safety, the system needs to know when the brakes are applied.
So what's my point? This discussion is in the Driveline section of Stovebolt and not the HiPo section.
Steering is the #1 priority. If you install EPS in another application or modify it with your own design, you take on the legal liability.
There is more to EPS that what you learn on a video link. Don't go at it blindly. Do some research and play safe.
I would question how much research you have done on this, despite urging others not to.
An EPS in failsafe mode (no CAN connection for any external vehicle information) behaves the same as any power steering system made in the last hundred years. It has a fixed amount of assist no matter what speed the vehicle is going. Adding speed sensitivity and/or wheel angle sensors allows for interesting additional features like the variable assist that some vehicles have, but those are very much not necessary as evidenced by the prevalence of saginaw based steerings that have not killed us all.
I am honestly curious why you think the steering needs to know if the brakes are applied. I have never seen that come up in any of the research I have done.
Making any kind of change to a vehicle from tire size on up theoretically opens you up to legal liability. No one complains about adding power steering by using the late model steering boxes despite that being an equally large change.
