Every scan tool I've seen offered to consumers only provides basic OBDII or CAN data. Some only offer the ability to view basic stored codes, and maybe a freeze-frame capability. This $20 scan tool from Amazon is a good example:

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Most of these basic ones don't offer any options to view "live" OBDII data or graphs, and I haven't found any that offer the ability to view proprietary OEM data that would normally be view-able on a scan tool a technician would use, like this $10,000 tool from Snap-On (Verus Edge):

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Clearly every gearhead would love to have one of these, but many of us don't have $5-15K to drop for one, let alone hundreds or thousands more on new software updates or personality keys.

These advanced scan tools give you visibility into thousands of more data points that can help you diagnose a problem, but with a universal scan tool, none of that is available to you. They're only really helpful if your check engine light is on, and even then, then they only give you a very limited idea of what's wrong in the form of a generic, stored CEL code.

Are there any affordable scan tools that come close to what one of those scan tools can do, that are available to the DIY-er? If not, why?

  • This is a nice question, but I thought shopping advice was off-topic for the site.
    – Zaid
    Feb 15 '18 at 15:49
  • @Zaid Then someone should probably update the help center, because it makes no mention of it either way.
    – user21327
    Feb 15 '18 at 15:50
  • I don't mind having the question on the site to be honest, because this feels like a meta-shopping question. It's generic enough that it should retain its relevance over time
    – Zaid
    Feb 15 '18 at 15:52
  • If there's any edit I can do to make it more "obsolescence-proof", let me know.
    – user21327
    Feb 15 '18 at 15:53
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    It really depends on if you’re only fixing one make or not. I own the Verus Edge but I use it for work. You could look at a used Solus. It doesn’t have a scope but it provides the same software diag capabilities as the edge.
    – Ben
    Feb 15 '18 at 17:24

If it has to be 'cheap' you do not want any proprietary hardware and software. So what you need is a basic ($15) USB or bluetooth enabled OBD-II scanner that can hook up to a laptop. The other thing you need is a look here: Any open-source OBD scanner analysis tools?

  • I bought a USB to OBDII tool a while back, but all of the software I could find doesn't really offer OEM-specific diagnostics. They're basically glorified universal scan tools, with the ability to monitor/record some sensors, but nothing vehicle-specific (as far as I can tell). Some software packages offer "Advanced" data for specific makes, but they're often only Ford, GM or Toyota. They're better than the basic code-reading tools, but still don't offer a whole lot more.
    – user21327
    Feb 15 '18 at 15:56

I bought one of these and it reads codes, clears codes and reads live data streams (reading the boost pressure the other day told me I had a split pipe... now been fixed):


  • Those are handy, but obviously limited to one or two specific makes, and can't be updated to support new models within those makes. You'd have to buy one for every make you work on.
    – user21327
    Feb 15 '18 at 16:00
  • @Moses that depends on how many cars you own - as you specified “diy”ers then you are not a professional who would be investing in the proper equipment. If you are running a business you are not a diy-er fixing your personal car, I use this one for my personal car... And yes, this one can be updated, in fact that was the first thing that was done when it came out of the box...
    – Solar Mike
    Feb 15 '18 at 16:18

Based on what is mentioned in the question, an ideal code scanner should offer:

  1. access to stored codes (and the ability to reset them)
  2. access to freeze frames (and the ability to erase them)
  3. logging/graphing capabilities
  4. access to OEM-specific signals regardless of make
  5. affordability/value for money

The first three can be addressed by universal OBD-II scanners, since most of these requirements are limited by software implementation (and protocols).

Sadly, the latter two are not so easy to accommodate for the following reasons:

  • OBD-II isn't meant to micro-manage vehicle OEMs

    Manufacturers have a certain degree of freedom on how they choose to store data for signals that are not covered by OBD-II. The only signals that stand a half-decent chance of being standardized are those which are mandated by government regulations.

    It should also come as no surprise that manufacturers prefer to keep information on how they store their data on a need-to-know basis. This is why the OEM-centric solutions that are available are usually based on dealership-level or engineering-level diagnostic systems.

  • It takes a lot of effort to reverse-engineer implemented protocols

    This is the primary reason for the seemingly astronomical price of all-in-one solutions. It takes time and determination to figure out how each system is implemented, and each manufacturer has their own quirks and caveats.

    The average DIY-er is unlikely to ever realize the full OEM-agnostic potential for such solutions; opting to purchase a vehicle-specific solution tends to be an acceptable compromise.