Choosing OBDII adapter

Car Scanner is compatible with ELM327 based OBDII adapters, working via classic Bluetooth (ver.1.x, 2.x, 3.x), Bluetooth LE (4.0) or Wi-Fi, depending on your device operating system.
You can find one on eBay, Amazon, Aliexpress, Google or Bing using keywords “elm327 bluetooth” or “elm327 wifi”.

It is the ELM327 adapter that provides communication between the program and the control unit of your car. The correct choice of adapter determines both the very ability to connect to it and the quality of the connection to the car, so it is very important to choose a good adapter.

If you do not want to read a detailed description and just want to know which adapter and where to buy, just scroll down.

What are the ELM327 adapters?

When choosing an ELM327 adapter, you need to solve two problems:
1) the adapter must be compatible with your smartphone or tablet, for this you need to pay attention to the type of connection that the adapter uses;
2) the adapter must be of high quality, that is, it must do its job, and not pretend that it does it.

By connection type, adapters can be divided into these groups:

1) WiFi
2) Bluetooth (classic, version 1.x, 2.x, 3.x)
3) Bluetooth LE (version 4.0 and above).
Please note that despite the similarity in name, Bluetooth and Bluetooth LE are fundamentally different communication methods. LE stands for Low Energy, i.e. low power consumption.
4) Bluetooth MFi is classic Bluetooth (1/2/3) that can be used with iPhone/iPad. The manufacturer of such a device must enter into an agreement with Apple and ship a ton of money to Apple, so such adapters are very rare. I only know two: OBDLink MX+ and vLinker FS. In the case of Android, such adapters work like regular Bluetooth.
5) USB – Not supported in Car Scanner.
Which one you choose depends on the operating system of your phone/tablet.

Apple iOS (iPhone/iPad)

Apple iOS (iPhone / iPad) and Car Scanner for iOS support Bluetooth LE (4.0), Wi-Fi and Bluetooth MFi adapters (this is classic Bluetooth, but with one essential condition: for such devices to work on iOS, an agreement is required between the manufacturer of these devices and Apple).
All other adapters using classic Bluetooth (versions 1.x, 2.x, 3.x) cannot be used with Apple iOS devices due to limitations in the iOS operating system. At all. No way. Not in any program.

Which type of connection should I choose for iOS?
My opinion: choose adapters with Bluetooth LE (4.0) because they provide the most comfortable and simple connection and acceptable data transfer speed and they are easy to find on sale. If you are ready to overpay for a top-end adapter with maximum speed, then one of the two models with Bluetooth MFi.
Do you want connection problems and broken mobile internet? Choose a Wi-Fi adapter.

Please pay attention to the Bluetooth version! This is extremely important for iPhone/iPad. Every day I receive letters from inattentive iOS users who bought a classic Bluetooth adapter in China and I have to upset them: it is impossible to use such adapters with an iPhone / iPad. Absolutely. No way. No other program will be able to use such an adapter either, because the limitations lie in the architecture of the Apple iOS operating system and cannot be overcome.

Google Android

Google Android supports adapters with classic Bluetooth (versions 1.x, 2.x, 3.x), Bluetooth LE (4.0) and Wi-Fi.
For Android, I advise you to choose adapters with classic Bluetooth: it is faster than Bluetooth LE (4.0) and more reliable than Wi-Fi.
95% of Android users use classic Bluetooth adapters.

Disadvantages: some Android smartphones/tablets do not work correctly with several Bluetooth devices connected at the same time (for example, with a Bluetooth adapter and a car multimedia system).

Choosing a quality ELM327 adapter. ELM327 versions.

First of all, forget everything you’ve heard about adapter versions, what chip should be inside the adapter and how many boards should be there. This information is outdated and does not affect the quality of the adapter. There are good adapters with version 2.1, there are bad adapters on PIC and two boards. Just ignore these signs because:
1) bad Chinese have learned to fake them very well in bad adapters;
2) good Chinese have learned to make good adapters on other chips;
3) The version number for bulk clones of the ELM327 adapter is simply three or four characters of text. If you really ask, the Chinese will write your birthday there.

According to their capabilities, ELM327 adapters are “good” and “bad” (you must agree, it’s hard to call defective something that was not supposed to work initially).
A good adapter does not stand out with something special, it just works as it should, does not glitch or freeze. Your goal is to find a good adapter.
Bad adapters carry a lot of different problems.

What’s wrong with a “bad” ELM327 adapter?

1) It may not work at all.
2) It can work unstable: for example, it freezes after a few minutes of operation, reboots spontaneously, refuses to work at low or high temperatures, in high humidity, or simply stops working at some point. Yesterday, the adapter connected and showed a certain set of parameters, but today it doesn’t connect or connects, but it doesn’t show all the parameters – and this happens to them.
3) It can only support a subset of the required control commands. The most vile adapters claim to support all commands, but in fact they do not support them.
4) It can be hard-coded to work with a standard ECU address so you can never communicate with any other ECU in your car.
5) It may have a limit on the length of requests sent and responses received.
6) It can lose data both when sending and when receiving them: the control unit can send 5 data packets, of which your adapter will accept the 1st, 2nd and 5th. It is impossible to decrypt such a data set.
7) It can distort data both when sending and when receiving it: you don’t want to send a command to erase the memory of the control unit instead of a temperature request command to the control unit, do you?
8) It can support only a part of the declared communication protocols with the control unit. Accordingly, if your car uses an unsupported protocol, the adapter will not work for you, but it will work on your neighbor’s car with a different protocol.
9) The most annoying thing is that they can short-circuit or spam the on-board network with junk data and requests, which will prevent the ECU from performing its main function – to control the engine. Many car owners have reported engine roughness while using these adapters.
10) If you are interested in the “Coding and Service” section, you need only a high-quality adapter! The mode of writing data to the ECU places special demands on the adapter, and with a bad adapter, at best, nothing will come of it, and at worst, you will write the wrong data set to the control unit. Do I need to explain that this can lead to very sad consequences?

The main problem is that there are far more bad adapters on the market than good ones. There is a real chance to buy 10 different adapters and 10 of them will be bad!

Which ELM327 OBD2 adapter should I buy?

First of all, I don’t sell adapters! All my advices are based on my own experience and Car Scanner user reviews. 

Worthy in my opinion adapters (I sort approximately from the most expensive to the cheapest):

OBDLink MX+ with Bluetooth MFi (#ad link). The price is about 100 US dollars. Suitable for iOS and Android. The most expensive, but also the most advanced adapter.

OBDLink CX with Bluetooth LE (#ad link).  The price is about 80-100 US dollars. Suitable for iOS and Android. Large memory buffer and excellent performance.

vLinker devices: vLinker MC+ with Bluetooth LE (#ad link), vLinker FS with Bluetooth MFi (#ad link), vLinker MS with Bluetooth MFi this is an attempt from the Chinese from vLink to make a competitor to OBDLink adapters. The first versions of these adapters were not very good, but then the manufacturer modified their firmware and now these adapters are very, very worthy. I recommend MC, MC+ (Bluetooth LE) or FS (Bluetooth MFi) or MS (Bluetooth MFi) for iOS or any vLinker for Android. Just remember what I said about the connection type: I advise you to choose Bluetooth for Android and Bluetooth LE for iOS and stay tuned for firmware updates. The first versions were buggy, but the manufacturer allows you to reflash them yourself at home. Updated firmware versions can be downloaded from the manufacturer’s website.

Vgate iCar Pro 2S – new device, that would replace iCar Pro BLE. It’s just better, so if you’re choosing between iCar Pro and iCar Pro 2S – choose iCar Pro 2S 🙂

Vgate iCar Pro BLE (#ad link) – This adapter has Bluetooth 2.0 + Bluetooth 4.0 chip, so it’s compatible with all operating systems (iOS, Android, Windows).
Attention: old firmware versions (before v.4.1.02 from 2021/01/08) of this devices doesn’t correctly support CAN Extended addressing, that is used on Toyota and BMW cars. To fix this please update firmware. You can download latest firmware for Vgate iCar Pro here.


Never buy this “bad” adapters:

  1. You should never buy xTool adapters, because they are not compatible with ELM327 and they can be used only with their own software.
  2. Don’t buy wired adapters (usb, com) – Car Scanner supports only wireless adapters.
  3. You should never buy adapter with word “mini” in it’s name. There’s a 99% chance to buy a “bad” adapter.
  4. Don’t buy cheap (<10$) adapters.
  5. Adapters with Bluetooth MAC address starting with 11:22:33 and 00:00:00
  6. KONNWEI devices (they were previously recommended for purchasing, but now they have reduced quality and devices often looses data packets)
  7. With name “Micro Mechanic” (a lot of them stops working after a short period of time)
  8. With name “THINMI.COM” (limited support of ELM327 commands, many fake responses)
  9. Adapters of brand “KUULAA”.
  10. Don’t buy adapters that looks like that (they are compatible, but most of them are very low quality):


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