ELM327’s and derivatives are the devices of choice if you want cheap, run off the mill hardware that works without any DIY.

They can be obtained for about 12 euro’s. It is somewhat slow, though we’ve been able to get more out of it than we ever expected.

Take good note of the following remarks:

  • The ELM is designed for OBD-II, diagnostics with a focus on emissions. Zoe uses quite different message types that need some tweaking. This makes it prone to firmware versions.
  • Get a KONNWEI / Maxiscan KW902. Others may work, most do not. Especially the 5 Euro blue ones usually do not. We have not noticed different firmware versions in the KW902′s, so as of now it is a safe bet. The advice came from the LeafSpy guys by the way, so it’s not just us, we are simply endorsing that advice, based on our own experience. Here is the quote from the people who build the LeafSpy app:
    Due to a recent cost reduction (and feature reduction) many of the cheap ELM327 OBD-II Bluetooth adapters from Asia no longer work with the Leaf and report themselves to be version 2.1. The only one currently recommended is the Bluetooth Konnwei KW902 which still supports all the needed ELM commands to communicate with the Leaf.
  • The Maxiscan KW902 and the OBDII 2 KW902 Scan Auto Scanner look the same, are probably identical inside and also work.
  • Note that they are sold with Bluetooth or Wifi connectivity. The current Android application only supports Bluetooth. The iOS version only supports WiFi. We are considering adding BLE support which should work on all phones.
  • We have also reports that a OBDLink LX modules work, at least the modules reporting V1.3. They look exactly like a Konnwei / Maxiscan. These will be usable starting CanZE version 1.9. The ones we’ve seen are a lot more expensive than the Konnwei’s though.
  • We’ve also had reports that Vlink and Viecar ELM devices work. We’ve not tried this ourselves.
  • The cheapest knock-offs usually do not work. Most contain stripped logic cramped in the spare room of their Bluetooth controller and these are too limited to work for CanZE. I was lucky with a 3 euro one but that is truly the exception.

If you experience problems with dongles other than the KW902, we are unable and frankly, unwilling to help. The KW902 works, it is relatively cheap, and it is simply not worth, if not impossible, to cross check 50 unbranded, unversioned knock off dongles against 75 Android devices. If you insist trying other than the dongles that we know work, you are on your own, but here is an acid test script. So…….

Don’t use
This housing is extremely generic and from it’s looks it is impossible to know what’s inside.
Don’t use
Don’t use
Again an extremely generic case

IMPORTANT: leaving an ELM327 plugged into the SAE J1962 connector might open up the car to serious security risks. Remember that, defined by the standard, the connector is always powered and at least part of the ECU’s can be awakened even when the car is totally powered down given the proper commands. Since the Bluetooth pairing code is 0000, 1234 or sometimes 6789, this is a serious attack vector. Use at your own risk.