I worked in the auto trade for a while. I loved engine and vehicle diagnostics. Electrical and computer problems and learning how everything worked.
I would love to be able to learn to build my own scan tool software and make it work. But the biggest thing blocking this is the whole right to repair thing. Sure you might be able to understand the data on the CAN network, ODBII. But… its going to be hard to understand everything going through the network on each vehicle. The other issue newer vehicles are going to use new systems. Even some vehicles in the future moving to a lan network to have better speed and reliability. The biggest issue already starting? Everything in the name of Security.
The training I was taking while working on all these vehicles was showing me a future, of how vehicles as we know it will because even more harder for small shops to repair. We’ve had problems which 4 /5 scan tools couldn’t properly display, access a module etc. People think “Oh it has ODBII port on it I can diagnose all the problems with that” - Which gives only engine data, fuel trims, if its passed the vehicle monitors and that’s about it. What if you need to access the instrument panel? The ABS Module? The Traction Control? The Air bag system? The Compass Module? The transmission control? Evap system? None of that goes through ODBII, all of that is the Can bus system (or network system). The new security also blocks all access to any of that data. Why? Integration, turn up and down your stereo while driving, speed up and slow down your wipers depending on speed. Remote Start etc.
People were stealing cars by connecting to peoples stereo through bluetooth (which connects to the CAN bus network. So they got access to the vehicle, start it and steal it). So now rolling out in newer vehicles you have subscription based security that forces you to only be able to gain access to the vehicle by being a valid and paid member of say Chrysler, Chevrolet, Ford, Ram, BMW, and the list goes on. You have to use security devices from snap on, launch and other companies that connect to the network, often inside the dash. Which means the removal of hvac, stereo, and other parts to hook up the security device, then hook up your scan tool to that. Which will then connect to the dealerships and verify if your allowed to access the vehicle and pass through the security system.
We gained the ability to have our music turn up and down while driving depending on speed. But lost the ability to see why our ABS light is on without having to go to an authorized shop / dealership in the name of security.
The computer / laptop / would 100% be the easy part of the problem. Building the software for a few vehicles. Say if the shop only worked on specific fleet vehicles, you may after many, many hours of work be able to design something that would work. Through essentially reverse engineering / hacking.
The other thing people overlook that the scan tool does. Is its not just read outs, and data. Its also Bi-directional. Gives you control on modules, relays, the ability to turn on and off solenoids. Run relearn procedures for throttle bodies, cycling the ABS module to purge out air in the brake system. Reset problems for learned fuel alcohol content (going from E85 to regular gas). The list goes on.
I think it could be possible to eventually have a laptop / computer be able to connect to these systems without paying thousands, or spending millions of hours. But it would require automakers, dealerships, software engineers to be forced to design it in a way that is universally accessible and fully open. The ODBII port was designed for this reason. But was government mandated over 25 years ago. Which knowing how government works. Is extremely slow to change laws or reform. Maybe with right to repair passing things will change? One can really hope.
Sadly, in this current state of the auto repair industry. If you work on multiple years, multiple manufacturers, multiple forms of repair. Your going to need at minimum a snap on scanner (and the future security module for it). Software updates for future vehicles, and updates for problems with current vehicles. And likely at minimum 1-2 other scan tools. Because simply having one won’t be enough. The snap on scanners are not perfect and will have problems.
I am with you tho, I really really want to be able to have a open source scan tool for my laptop that doesn’t cost 10 Grand. - With how the future of automotive repair has been going, its made me get out of the industry, its just so frustrating constantly fighting with dealerships trying to lock down the repair.