This topic is also discussed here - http://canze.fisch.lu/elm327/
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. The Zoe and Fluence ZE use 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.
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 seen another branded version that works. It is called an iKKEGOL® Mini V1.5 Bluetooth Wireless OBD-II (Links: Amazon), but we have not seen it on sale any more and it seems to have slight timing problems. We do not recommend it but you can try if you happen to have one.
The cheapest knock-offs 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.
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...
and at the end they state -
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 1234 or sometimes 6789, this is a serious attack vector. Use at your own risk.
My own opinion on the chances of hacking occurring via the OBD are that it is infinitesimally small, and that we should not worry about it. There are only about 20 Soul EV cars in the world with this this hardware. No hacker would ever find a target. And SoulEV2016 has shown that the CanBUS is not fully active when the smartkey is not present. There may be a way to activate it, but we don't know it. No random hacker is ever likely to develop that capability.
That I have an extension cable for my KW902 is more about not having to open and close the plastic cover in front of the fuse box. It is tidier to have the KW902 in the centre compartment. I prefer the cable with the switch, but I don't think it makes any practical difference to get one without, like the one SoulEV2016 has shown.
The codes for using Torque Pro can be found by clicking the link in the website icon under my user name on the left.