DIY Car Diagnostic System using VCM?

VCM = Vehicle Communication Module. Which are modules made for different car manufactures for diagnostic purposes.

So, I won’t go into the details. But someone I know who owns an automotive repair bushiness and is a licensed mechanic asked me about making a Diagnostic System out of a laptop possibly using Windows 10 enterprise, not sure about Linux for this task?

These types of devices do exist from companies like Snap-On. They sell a model called the VERUS Edge that I had a look at one in person, and the base is a durable tablet with a celeron 1.8ghz CPU and 2GB’s of RAM with a 32bit version of Windows 10 Enterprise and a display resolution of 1024x600 . Garage owner said it cost around $9KCND.

https://www.snapon.com/EN/UK/Diagnostics/Products/VERUS-Edge

The snap-on tablet does come with its own software
for connecting to all the mainline car manufacturer VCM packages. The device also contains a meter that never gets used.

There are also custom ARM based tablets from Snap-On too.

The owner of the shop inquired me if I could build one for under $4K CND. Preferably using toughbook, or something that could get thrown around a garage and survive? Maybe some sort of SBC set-up? Though I do not have any experience to make my own cases.

Any help would be appreciated.

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The issue here is that you may not get access to or may not be able to touch the Vendor specific stuff. Congress mandated that the information has to be made available in the standard, but the vendors do not have to provide the secret sauce for their custom codes.

You can buy a bluetooth dongle or a USB attached dongle to connect to the OBD port. New stuff uses CAN Bus but the older ODB1 and ODB2[a,b] stuff uses the original ODB standard communication which is basically rs232 at the vendor standard baud rate.

There are hand held scanners that can be had for less than 200 USD that could solve this problem as well, unless they want a laptop form factor.

The other issue that you may run into is that usually, the Sanp-On joints will give you some common troubleshooting steps and procedures or references to the manufacturer’s repair manual. A custom solution does not do that as far as I know.

You are safe sticking with an ELM based scanner or clone.
https://www.amazon.com/bluetooth-obd2-scanner/s?k=bluetooth+obd2+scanner

https://www.amazon.com/s?k=USB+obd2+scanner&ref=nb_sb_noss_2

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I live in Canada, and I am trying to read up on the laws here.

I have built the odd PC for people in the past, but nobody ever offered me a job proposition, like this. So I am really not too familiar with the diagnostic hardware.

I only had experience with a Snap-On branded touch screen tablet that uses Windows 10 Enterprise. They do seem to offer their software package for PC’s.

OBD I and II look like the old long existing standard for North America. Bluetooth sounds ideal. The owner of the shop said they mostly used USB adapters. Will have to look up CAN BUS. He also mentioned EOBD 1 and 2 for European cars as well as a Japanese diagnostics system.

The owner of the shop asked me about finding a good durable laptop for shop use. Panasonic makes a laptop called the Toughbook. It seems like SingleBoardComputer software is available as well. Could a Pi with a touchscreen in a protective casing work?

I will look at handheld scanners. But I think one core unit may be best. This is a garage with a dozen employees.

I can’t compete with their customer service. That’s why they charge premium prices. That is a concern I thought about.

Your post has been incredibly helpful so far.

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very much doubt you could build your own for less than $9k USD unless your time is FREE. Certainly not anything with the same or even similar level of reliability/features.

And in the interim, during development what’s he going to use?

You’d certainly not get updates for new models, etc. at that cost. And I doubt you’d be able to test against any significant fraction of the vehicles on the road.

Sometimes things cost what they cost because the alternative (doing it yourself) is cost prohibitive.

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Tough books or Samsung has a line of mobile devices and tablets that are hardened against shock and water.

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I can’t imagine being able to decode all the info the snap-on scanner can to be honest. With newer CAN systems with individual controllers for everything from windows to engine control, interpreting that data, then being able to visualize things such as fuel curves, sensor ranges and waveforms from pickups and odds and ends it would be really hard to compete. Those scanners also have modules or packages for different manufacturers depending on your shop that are updated regularly as stated above.

If you really want to do it I’m sure you could get some functionality from standard OBDII. Maybe you should see what your customer needs out of the scanner and on what makes and models. The interfacing and programming is a whole other animal. Manufacturers are so wildly different in how they optimize and manage their products. If Chrysler can hear me… you guys are the devil. Lol Just my two cents from being a mechanic for 10 years or so.

I had a $30 code reader and did my diagnostics the “old” way by driving, feeling, and inspecting. I used a snap on MODIS and it’s amazing but sometimes overkill.

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Also… having a look around… Foxwell do some diagnostic tablets that sound similar to the snap-on thing, available for under $1k USD.

Reckon you can build one cheaper/better than that? :slight_smile:

https://www.foxwelltech.us/product-more-1.html

I’ve got one of their OBD2 scan tools… does the job for what I need personally.

edit:
I very much suspect the shop owner has no idea about software development time/costs - like most normal people. He sees the $9k tablet, thinks “an iPad is $400” and has asked if you can do it for half price.

Most people don’t understand that it’s the software and support that is the expensive bit; the hardware is incidental really.

Don’t get me wrong, it would be an interesting project, but this guy is running a business… and it would simply not make economic/business sense to roll your own.

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Well, I never said I could compete with a billion dollar company. I was looking at building something that could do most of the same tasks. Even looking at Snap-On’s site, they do have their software as a separate package. Maybe for a subscription? I am looking into that.

It seems like there are DIY options, using packaging. Or more like BYOL/ Tablets?

I will talk to the owner of the shop. Looks interesting.

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Yep, I used them with the US Military. They are durable but pretty weak computers. Dell used to make a variant of these that they were only able to sell to the Air Force. You may be able to find one of those for cheaper than a Tough Book.

If I am not mistaken (I only have one car that uses CAN), the ODBII connector is used for CAN Bus here in the USA/NA. The eODB and jODB standard uses the OBDII connector as well but they speak a little bit different protocol. You ELM based adapters (and STM) are polyglots and speak the language and spit out standard ODB on the other end.

I am here to help. I took on such an endeavor in the tuner world. It was less about fixing cars and more about reading codes and telemetry.

You can use a Pi or any other single board computer to read this with the correct Adapter. STM also sells ICs that will read OBD and allow you to interact with the car using STM opcode and registers. Was pretty cool but the Torques program came out so I stopped working on that solution. Torques works with any ELM clone.

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Building your own car diagnostic system would be time consuming to piece together a setup(may it be a mix of opensource and some commercial solution(s)), newer vehicles are much more complex and newer models tend to shift to different OSes(ex: some auto makers used Windows Embedded then they shifted some models to Android/Linux). There are code readers however you may still need to data log the CAN bus as off-the-shelf code reader may only give an end-user a limited amount of info vs Snap-On. Unless your boss has contacts who work for dealerships it’ll be more work of poking at telemetry logs and going by observation.

Having said that, I’ve had friends nag me to help on code/telemetry and sometimes you have to nearly reverse engineer your way into finding out how everything is tied into the CAN bus to understand what a certain code is tied to. Its possible to have multiple fault codes related to a specific part of the vehicle too–for example a $1-5 part that is in short supply can impact multiple functions. I would say hybrid vehicles are the hardest in terms of troubleshooting.

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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.

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I know some people who are into tweaking their own vehicles. Or soft modding them, or whatever. Not something I am into myself. But it seems like a fascinating thing to get into. Some people I know would get into every tweaking aspect of their vehicle.

I see. The shop owner that made this request to me, has a small staff. But is licensed, with long-term mechanics. Most of the cars they work with seem to be 10 years or older. Which is about the norm. Since many newer cars are still serviceable from the dealers.

I have little to no experience working at a shop. I did janitorial work for one once. Haha. But I could imagine the discrepancies between different cars and companies.

Yeah, I heard about stuff like this. But not in detail.

The Snap-On tools sets seem to use standard windows PC’s with touchscreens or ARM based tablets. And they are nothing special, aside from their custom protective casing and odd additional features.

Looking at software options. TOAD Pro, OBDWiz, Touchscan, etc. Not sure how any of these fare.

It really comes down to Snap-on’s own software packages, durability/ tech support and etc. Just using them as a base example, as I know there are other competing products too.

The garage owner said that the majority of diagnostic plug-ins that they use are USB. Or have USB connections.

I don’t know if ‘right to repair’ is much of an issue. As this is a licensed auto repair shop. The garage owner wants to undercut paying premium prices for equipment. DIY seems impossible for me. It seems like a basic laptop with the right software and hardware might work?

Could those software updates be installed on any Windows 10 machine?

That’s the case with so many different types of tools.

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Yeah thats typically about the norm, with the odd vehicle that may be 3-4 years old. But that is in the range of needing more newer scanner units.

Correct, they just run a version of windows. But they do have custom hardware built in for the wireless Diagnostic Module, the scope addon etc. What your really paying for is the snap-on Software.

Its mostly getting the software from say Snapon, onto a laptop. Then managing to get the connection from the scan module, either wireless or wired to work with the laptop. Any time I saw updates from snapon, it happened from the snap on truck, normally when you purchase a new one you get free updates for a while (just don’t remember how long). The other issue of doing something like this, would be liability, the shop could get into legal action for “Illegal use of software” or similar. Getting updates for the software from snapon tuck onto a laptop, I couldn’t see realistically happening.

Yes the biggest thing is the software from Snapon, similar with other companies like Launch, Autel etc. You may be able to get the connections you have to recognize and maybe get the drivers. But its the software you need.

I would keep away from those, those are only ODBII scanners. Which you can get on amazon for $50-$100. Also similar to the BlueDriver Bluetooth Scanner. (The one that you use through your phone). There is a huge difference between standard ODBII scanners, and full vehicle diagnostics. If you lookup on youtube can bus hacking, it will give you an idea of what kind of work / programming you’ll need to do.

What I think you’re after will be difficult, if the person you’ve been talking to doesn’t need scan tools super often, it may be worth while to get cheaper scan tools, or even used SnapOn scanners. But… those can be still pricey + no warrenty. (Plus if you want snapon to update it for newer vehicles, it can still cost $500-$800 + depending on the scanner) Snapon verus would be an example on ebay (But they are pretty darn old at this point)

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Oh absolutely.

From what I can tell, they have Windows 10 Enterprise variants as well as ARM based tablets that run a different set of software.

yeah, I noticed that. The unit I held had some sort of built-in UV meter and a port that looked like a VGA connector. The software is a big part of the package. as well as the support.

And, I just want to say that I am not trying to rebuild the wheel. :stuck_out_tongue: For me, this is a investigation in seeing what kind of hardware/ software could be bundled together to get somewhat similar results.

And, not trying to break any laws with pirated software. Really don’t want that to be an option if it gets a garage in some hot water.

I think those hand scanners are preferable for personal garages. The owner of the garage I am dealing with has been in business for about half a dozen years. His staff are mechanics by trade, and people who have worked in dealership garages.

His inquiry to me was that he wanted a single laptop device that was durable. With appropriate software and plug-ins for the most common diagnostics connectors. Maybe using multiple hand tools might be harder to keep track of in a busy work environment.

And I just want to say, that I thought it might have been a bit of a crapshoot asking this on this forum. But I am surprised by the responses. Nice to get information from people with real foresight.