Can a Bluetooth ELM327 adapter be used to flash a VIN?

It's claimed here that

The vin number is about the only thing in the PCM that's not a protected value.

1 Answer 1


My understanding is ... yes, you can. Don't go away so fast though ... there are caveats:

  • The ELM327 device is only a passthrough. It is just a connection from your device to the PCM. There is no way (to my knowledge) to use just the ELM327 device for this.
  • You have to have software to read, modify, and write the new VIN back into your PCM. Most often, the read/write software is different from the modifying software.
  • This will not work on every vehicle. Some require specialized equipment.

The guy in this video briefly talks about using an ELM327. He uses other equipment to do it. You can see what he has to do to get the VIN changed on the GM PCM.

  • Interesting. There's probably some open-source software on GitHub that could be used.
    – Geremia
    Commented Dec 9, 2022 at 0:01
  • I forgot I asked "Open source software for automotive ECUs?" on softwarerecs.stackexchange.com in 2017. It hasn't received any answers…
    – Geremia
    Commented Dec 9, 2022 at 0:06
  • @Geremia - Something to remember which I didn't state is, you can most likely use the ELM327 for doing what you're suggesting, but the real question is: Should you? My suggestion is, not at all. Reason being is, the ELM327 has to be open to receive electronic interference. Because of this, if you should happen along any, you can brick your ECU, which means ... it's dead. Not much you can do but use it as a paperweight at that point. Commented Dec 9, 2022 at 2:05
  • I'm familiar with putting custom firmware on routers and bricking them. There's usually a way to restore the factory firmware.
    – Geremia
    Commented Dec 9, 2022 at 17:31
  • @Geremia - When I say "brick", I mean brick. As in: no longer works. Commented Dec 9, 2022 at 19:16

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