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 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, 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.

49 comments on “ELM327
  1. Stefan says:

    the iKKEGOL® Mini V1.5 Bluetooth Wireless OBD-II is no longer available at amazon. Maxiscan does not work in my ZOE.
    Has anybody experiance with Diamex OBD II Bluetooth-Interface Diamex DX70 or cartrend Bluetooth OBD-II Car Interface or dnt OBD-Scanner (all between 50 and 100 Euro)? Hope to get it working somehow.
    regards, Stefan

  2. GertjanVB says:

    MaxiScan didn’t work at first in My ZOE either. After some serious swearing and a time-out, I took a ride with the MaxiScan switched on and it started to work. Apparently it needs some time to establish the first Bluetooth connection

  3. cece74 says:

    Is there a practical reason why version 2.1 will not work, or is just that you just only (yet?) figured out how to have 1.5 working?

  4. Jeroen Meijer says:

    “Real” 2.1 devices, meaning with a genuine ELM chip should actually work. Chinese knockoff’s reporting to be 2.1 are unusable as (see abve) “most contain stripped logic cramped in the spare room of their Bluetooth controller and these are too limited to work for CanZE.”. They can never work as they miss the ability to pickup real time information from the bus. They will never ever work.

    So the question is then: how do we know it’s a real 2.1? Well…… we don’t and the ELM-manufacturer won’t tell. Let me assure you:
    – the stuff on Ebay is all in the knockoff category;
    – the Konnwei / Maxiscan 1.5 works

    There is really no incentive to pursue anything else and we won’t as we can’t: we would happily support and actually promote real 2.1 based dongles but as the manufacturer makes it impossible to know which ones are real and the sellers are lying, there is nothing we can do. The problem is that most buyers stubbornly try the EUR 5 dongle anyway and “2.1 must be better than 1.5”. I hope it is clear that really, no, it isn’t and the given advice is given to protect you from disappointment.

  5. Stefan says:

    Hi Jeroen, relax, after a new Maxiscan and update of software it works now and I have something to play ofer Christmas. All the best for you and thank you for the very good project. You really help e-mobility a step forward. Thank you also for the complete team beiing involved.

    • Jeroen Meijer says:

      Thank you for the heads up to the team, it is truly appreciated. I am glad it works now. Have fun and while our pace is a bit slower now, we have interesting improvements to come, and we think it will potentially save drivers money. Now I really need to get a good mount somewhere 😉

  6. Philipp says:

    Hi guys.
    I found your great app and I want to analyse my zoe.

    I got a OBDlink mx bluetooth from my c-zero. It works fine with canIon.
    Can-ze version 1.09
    Tablet: asus me137, android 4.2.2

    I’m able to connect it with your app. Bluetooth led is solid, power led as well.
    CanZE say there is a connection with the obdlink mx (can see the mac-address)
    Orange and red led (those between blue and green are off.
    No data transition to the tablet

    Why are there no data visible? Any clues?


  7. Philipp says:

    Where can I find the version Bob?

  8. Philipp says:

    Obdlink mx bluetooth
    Rev. 2.2/R3
    Mfr: 2013.09.27
    Id: X4ZBTMOD4

  9. ABE Fluence says:

    Buyed new Maxiscan. No power in ODB2 from Fluence ze. Maxiscan power light ok in other cars…so the problem is car. Is there any fuse to check?

  10. ABE Fluence says:

    Thanks a lot.
    Cigarret fire works ok….and i know some renaults use the same fuse for both. I think fluence ze dont.
    I have photo fuses….to compare…..perhaps seller retire fuse to avoid scan.
    Waiting news

    • ABE Fluence says:

      Tested VC pins 4 and 16. 12.5v off and 14.5v moving key. So i dont understand why no power in Maxiscan. Other cars ok. Any ideas?

      • Jeroen Meijer says:

        Sorry for not answering earlier. The Fluence driver id not have information about the proper fuse location. I think that is confirmed by your measurements.

        He did mention that the SAE J1962 connector is a bit troublesome and you really need to press in the dongle pretty hard. It only needs power to at least light the LED. I hope this helps.

  11. François MALATERRE says:

    Hi My “chinese” OBDclick dongle doesn’t communicate.
    Diag here, a solution ?
    Scan date=2017-01-04 22:33:59
    Device name=OBDII
    Device mac=00:1D:A5:68:98:8B
    Device Version (Declared)=ELM327 v2.1

    Command Version Result
    AT@1 1.0 OK
    ATSPA6 1.0 OK
    ATTPA6 1.0 OK
    ATTP6 1.0 OK
    ATSP00 1.3 KO
    ATSP6 1.0 OK
    ATAL 1.0 OK
    ATNL 1.0 KO
    ATAMC 2.0 KO
    ATAMT20 2.0 KO
    ATRA70 1.3 KO
    ATSR70 1.2 KO
    ATAR 1.2 OK
    ATAT0 1.2 OK
    ATAT2 1.2 OK
    ATAT1 1.2 OK
    ATBD 1.0 KO
    ATBRT0F 1.2 OK
    ATCAF0 1.0 OK
    ATCAF1 1.0 OK
    ATCEA04 1.4 KO
    ATCEA 1.4 KO
    ATCF00000111 1.0 KO
    ATCF111 1.0 OK
    ATCFC0 1.0 OK
    ATCFC1 1.0 OK
    ATCM00000111 1.0 KO
    ATCM111 1.0 OK
    ATCP18 1.0 KO
    ATCRA7C0 1.3 OK
    ATCRA000007C0 1.3 OK
    ATCRA 1.4b KO
    ATCS 1.0 KO
    ATCSM0 1.4b OK
    ATCSM1 1.4b OK
    ATCTM5 2.1 KO
    ATCTM1 2.1 KO
    ATCV0000 1.4 KO
    ATD1 1.3 OK
    ATD0 1.3 OK
    ATDP 1.0 OK
    ATDPN 1.0 OK
    ATE0 1.0 OK
    ATE1 1.0 OK
    ATFCSD0430FF00 1.1 KO
    ATFCSH000007B0 1.1 KO
    ATFCSH7B0 1.1 KO
    ATFCSM0 1.1 KO
    ATFE 1.3a KO
    ATH0 1.0 OK
    ATH1 1.0 OK
    ATI 1.0 OK
    ATIB10 1.0 OK
    ATIB48 1.4 OK
    ATIB96 1.0 OK
    ATIFRS 1.2 OK
    ATIFRH 1.2 OK
    ATIFR0 1.2 OK
    ATIFR2 1.2 OK
    ATIFR1 1.2 OK
    ATIGN 1.4 OK
    ATIIA7A 1.2 OK
    ATJS 1.3 KO
    ATJE 1.3 KO
    ATJHF0 1.4b KO
    ATJHF1 1.4b KO
    ATJTM5 1.4b KO
    ATJTM1 1.4b KO
    ATKW 1.3 KO
    ATKW0 1.2 KO
    ATKW1 1.2 KO
    ATL0 1.0 OK
    ATL1 1.0 OK
    ATM1 1.0 OK
    ATM0 1.0 OK
    ATR0 1.0 KO
    ATR1 1.0 KO
    ATRV 1.0 OK
    ATS0 1.3 OK
    ATS1 1.3 OK
    ATSDFF 1.4 KO
    ATRD 1.4 KO
    ATSH000007E0 2.0 KO
    ATSHA848F1 1.0 OK
    ATSH7B0 1.0 OK
    ATST32 1.0 OK
    ATSWFF 1.0 KO
    ATTAF9 1.4 KO
    ATV1 1.3 KO
    ATV0 1.3 KO
    ATWMC133F13E 1.0 KO
    ATPC 1.0 OK
    ATWS 1.0 OK
    ATD 1.0 OK
    ATZ 1.0 OK

  12. François MALATERRE says:

    OK don’t be sorry, it’s my fault.
    I didn’t ear about dongle version before having this problem !
    When you say not suported, do you mean definitively ?

  13. amiral_sub says:

    Hi, is it dangerous to use my old elm generic device? Will I damage the car?

  14. Clive Dyson says:

    Could you please include the information about version numbers for the Konnwei KW902 in the text of this page to state that version 2.1 of the firmware will NOT work, as per your comments in response to peoples’ replies. Having read the text carefully, I bought one from amazon.co.uk and I’m almost certain it is a genuine Konnwei, but it arrived with version 2.1 firmware.

    Your page needs to give clear instruction in the text for the page (not the replies) that people must buy version 1.4/1.5 firmware.

    I suspect that Konnwei will have stopped producing devices with earlier firmware, so relying on the earlier firmware is going to become intractable at some point. I’m happy to ship you the version 2.1 Konnwei I’ve bought for development use, if that helps.

  15. Laëlien Roussat says:

    Thanks for your amazing app, will it work with a freematics ONE ?

  16. Jeroen Meijer says:

    Not “out of the box”. I have one laying around, but there are many configuration options for the hardware. It is actually a VERY compelling device. Thing is, to do it right, we’d have to make firmware for it, and I would expect it then to be super fast and much more reliable than the KONNWEI’s, but for our limited resources and the only handful of people having one, it doesn’t seem to be worth the (substantial) effort. I guess that is a long “No”, sorry.

  17. Vincent says:

    Should be great (for security reasons) to be able to use ELM324-usb cable instead of bluetooth.

    • Jeroen Meijer says:

      True, but then AFAIK you need a special cable and OTG support, which a lot of Android phones do not have. It’s opening basically another can of worms!

  18. John says:

    Buying an OBD2 KW902 dongle that works seems to be a bit of a lottery.
    I bought this one from Amazon https://www.amazon.co.uk/gp/product/B0785F9P57/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
    What they sent me came in a box marked 901 so have sent it back.

  19. Rudi42 says:

    I have bought a dongle at Amazon (Vgate iCar 2 Bluetooth EOBD OBDII) for my ZOE and it seems to work. The Elm test is passed without problems (Elm v2.x), but it does not show the tire pressures correctly. How can I detect wether it is the dongle or the software?

    • Jeroen Meijer says:

      If the ELM test works, it works. There are two types of ways needed to operate CanZE and the ELM test probes them both. Please be aware not all ZOEs have TMPS (mine doesn’t). Also note that the pressure is only transmitted and thus displayable after driving a few 100 meters if your ZOE *does* have TPMS.

  20. Ben says:

    I have found a double chipped ELM327.
    2x PIC18F25K80 Chip ELM327 USB V1.5
    Would this work?

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