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According to https://en.wikipedia.org/wiki/ELM327#Other_Versions there is a handful of different versions of ELM327.

If you buy a non-genuine ELM327-device (that is, something that is compatible with ELM327 since it seems to be a de facto standard, but not manufactured by ELM), can you verify which version of ELM327 it supports?

  • Only the manufacturer would know. – Moab Sep 24 '19 at 15:29
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    Welcome to Motor Vehicle Maintenance & Repair! I think your understanding of the device might be slightly askew. ELM327 is the interface which bridges the gap between the CANBus and an RS232 which goes out to your device (computer or smart phone). It appears to me ELM Electronics sells their ELM327 chips, which are then integrated into a reader by whomever. In order for it to be "ELM327", it has to have one of these chips in it. There is no "compatible" as far as I can tell (I could be wrong ... and I wouldn't put it past the Chinese to make duplicates). – Pᴀᴜʟsᴛᴇʀ2 Sep 24 '19 at 15:49
  • I know for a fact that some readers refuse to work with some cars, even though they are "ELM27"... So I was very careful buying mine for my car - it works perfectly and already saved me more than its cost price... – Solar Mike Sep 24 '19 at 15:56
  • @Pᴀᴜʟsᴛᴇʀ2 Are you sure about that? I am looking for a ELM327-device that supports Bluetooth 4.0 so I can use BT with en iOS device but AFAIK no devices using a genuine ELM chipset (?) offers that combination. However, 3rd party devices like this amazon.com/X-ELM-Bluetooth-Diagnostic-Compatible-Vehicles/dp/… seems to do it but they are called X-ELM which someone told me means that they are reverse engineered ELM devices. But if you know of any genuine ELM-device that supports BT 4.0, I am all ears! – d-b Sep 24 '19 at 21:44
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    The Bluetooth controller is typically a separate chip from the main controller, so the versions of the two are independent. Not that that helps find a genuine version... – Phil G Sep 25 '19 at 14:29
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As the article says, the copies can often misreport what code version they have, so that's of no use in determining what they can or can't do. All that can be extracted from the microcontroller is the machine code that sets up and operates the microcontroller, not the original source code, so modifying it substantially is likely beyond most of the clone manufacturers.

Further to the pirating of the original code from ELM, the microcontrollers that it runs on are also commonly cloned, and the electrical performance of the devices can deviate from the datasheet values. The most common effect is that they can occasionally lock up, and will only reset by being powered off for a few seconds by unplugging them. PICs have a built-in "watchdog" that monitors for this, and resets itself automatically, but this may not be implemented on the clone hardware - or even on the early version of the genuine ELM for all I know.

Practically, there's little difference between any of the clones, they all run pretty much the same code, and my $7 device has worked in every vehicle, and with every OBD scan app or virtual dashboard app I've tried.

  • Can't you test its capabilities? Send some commands and see if you get a response that makes sense? – d-b Sep 24 '19 at 21:45
  • How big is the difference between ELM 1.0 (which seems to be the most common version among clones) and 2.2? – d-b Sep 24 '19 at 21:55
  • The Wikipedia page links to some of ELM's documentation, including the command list elmelectronics.com/wp-content/uploads/2016/07/… I haven't tried using this to determine what version mine is, but I'd assume that it's 1.0. – Phil G Sep 25 '19 at 14:05

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