An ELM327 interface serves as a connector that lets you connect your car to computers, tablets, and smartphones. You can connect to any Android, Windows, or iOS device with the help of ELM327 device.
Although ELM Electronics makes the chips that ELM327 devices run on, other companies take those chips and use them to make ELM327 adapters. Each of those adapters is what is called an ELM327 interface.
It’s called an interface because it acts as a link between a vehicle’s on-board computer(ECU) and your external computer (smartphone, tablet or PC). With it you can view real-time data from the ECU, run some diagnostics and read/clear codes that are associated with the Check Engine Light.
Generally, an ELM327 scanner operates based on three sub-parts. The first is the ELM327 chip. This is an integrated circuit that’s rated at 4MHz. It is the brain behind the whole device onboard its purpose is to convert data from the ECU to a format that can be understood by modern computing devices.
The second sub-part is the set of electric voltage adaptors. Their primary function is to identify the various on-board systems of a car using their unique voltage properties. For example, an ELM327 scanner is able to distinguish the EVAP system from the fuel system using its electric voltage adaptors. They are usually given as protocols like CAN, K/L or PWM/VPN.
Finally, there is a set of voltage adaptors for PC. These ones make it possible for an ELM327 adapter to adapt its electrical levels to those of a computer device (PC, smartphone or tablet). By doing so the adapter and the computer can successfully communicate.
Let’s start with the recommendation of the Editor.
Best ELM327 Interface
|Editor's Picks||Product||Connection||Our Rating|
|Best Overall||Vgate iCar2||WIFI||9/10|
|Runner Up||OHP ELMconfig FORScan||USB||8/10|
|Best Budget Buy||Foseal||WIFI||8/10|
|Best Value||FOXWELL FW601||WIFI||7/10|
|Also Great||ELM327 Mini||Bluetooth||9/10|
Jump to the product review HERE
Table of Contents
- 1 Best ELM327 Interface
- 2 Types of ELM327 Adapter
- 3 What Functions Can ELM327 Interface Offer?
- 4 What Protocols Are Supported By ELM327?
- 5 Best ELM327 Adapter Reviews
- 6 How To Use ELM327 Interface
- 7 OS Compatibility of ELM327 Adapters
- 8 Are There Drawbacks To Using ELM327?
- 9 FAQs About ELM327
Types of ELM327 Adapter
There are three types of ELM327 Adapter: Wifi, Bluetooth, and USB
Up until 1996, car manufacturers had their OBD standards and protocols. Auto mechanics were forced to keep up with the latest trends in technology, which made diagnostics very complicated.
The ELM327 Interface lets mechanics perform diagnostics using cost-effective hardware. Having a universal interface helps mechanics address common automobile issues effectively.
Bluetooth ELM327 adapters are capable of transmitting radio waves between a car and ELM327-compatible devices. File transfers are hassle-free using Bluetooth, and you do not have to plug-in wires. Considering very little data is transferred using the ELM327 interface, data transfer speeds are not very relevant.
Most users prefer wi-fi ELM327 adapters, and you also have more options available for purchase. The technology does suffer from a significant issue when it comes to connecting to Android devices. If you want to use an Android device, you can’t stay connected to the internet when the ELM327 interface is in use.
If you own an Android device, your options are limited to Bluetooth adapters only if you want uninterrupted internet connectivity. iOS owners, on the other hand, can choose from either Bluetooth or Wi-Fi options. You always have the option of purchasing a wired adapter as well if power consumption is an issue for you.
What Functions Can ELM327 Interface Offer?
I have mentioned from a general point of view that ELM327 allows you to view real-time data from the ECU, run some diagnostics and read/clear codes. I should add that as an OBD2 adapter, ELM327 works with a diagnostic app/software.
What you do is that you install the app/software on your smartphone/tablet/PC and use it as a diagnostic platform.The exact range of functions that you will get depends on the app or software you are using. I will talk more about that later in this post, but for now here are the most common functions of ELM327:
Diagnostic Trouble Codes (DTCs)
As a bi-directional diagnostic tool, ELM327 allows you to read and clear generic as well as manufacturer-specific codes. You can view the definition of each code and determine whether the problem needs you to take the car to the shop or if you can handle it the DIY way. Note that when you clear ECU codes you can turn off the Check Engine Light (CEL).
In addition to codes, you can view PIDs and emission data. PIDs are graphical representations of sensor data. By observing them you can tell whether your car’s on-board systems are performing normally or if there’s an abnormality that requires your attention. Emission data, on the other hand, indicates whether the car will pass federal and state smog tests.
Diagnostic data is great for pinpointing problems. Live data, on its part, shows you the performance of your car. ELM327 provides real-time data that you can use to analyze things like engine performance and fuel economy. Here’s a list of the live data that you can view:
|• Absolute Throttle Position|
• Air Fuel Ratio
• Average Trip Speed
• Barometric Pressure
• Command Equivalence Ratio
• CO2 Emissions
• Distance Traveled Since Clearing ECU Code
• EGR Commanded
• Engine Coolant Temperature
• Engine Load
• Engine RPM
• EVAP System Vapor Pressure
• Fuel Cost
• Fuel Level
• Fuel Rail Pressure
• Fuel Used (trip)
• GPS Altitude
• GPS Latitude
• GPS Satellites
• Intake Air Temperature
• Kilometers Per Liter
• Miles Per Gallon
• O2 Volts
• Relative Throttle Position
• Timing Advance
• Transmission Temperature
• Trip Average MPG
• Trip Time
• Voltage (Control Module)
|• Accelerator Pedal Position|
• Ambient Air Temperature
• Catalyst Temperature
• Cost Per Mile
• Distance to Empty Fuel Tank
• Distance Traveled with Check Engine Light On
• EGR Error
• Engine kW
• Engine Oil Temperature
• Ethanol Fuel Percentage
• Exhaust Gas Temperature
• Fuel Flow Rate
• Fuel Pressure
• Fuel Trim Bank
• GPS Accuracy
• GPS Bearing
• GPS Longitude
• Intake Manifold Pressure
• Mass Air Flow
• O2 Sensor
• Relative Acceleration Pedal Position
• Run Time Since Engine Start
• Throttle Position
• Trip Average KPL
• Trip Distance
• Turbo Boost and Vacuum Gauge
• Volumetric Efficiency
You can log both diagnostic data and real-time (live) data to your phone, tablet or PC. ELM327 gives you the option to receive the data via Text file or email. However you prefer, you can share it with people who understand diagnostics better in case you need someone else’s opinion.
What Protocols Are Supported By ELM327?
ELM327 is not the only ELM interface around. Its predecessors, the ELM320, ELM322 and ELM323 are still very much available for purchase and use. However, the 327 version is the most popular because it supports all OBD2 families of protocols.
ELM320 supports only one type of protocols; the PWM. The same goes for ELM322 and ELM323 which only support VPN and KWP protocols respectively. On its part, ELM327 is fully compatible with all types of protocols.
More specifically, it works with CAN, KWP, PWM, and VPN. That translates to all OBD2 protocols. Here’s the list:
- ISO 15765-4 CAN (11 bit, 500 kbit/s)
- ISO 15765-4 CAN (29 bit, 500 kbit/s)
- ISO 15765-4 CAN (11 bit, 250 kbit/s)
- ISO 15765-4 CAN (29 bit, 250 kbit/s)
- ISO 14230-4 KWP (5 baud init, 10.4 kbit/s)
- ISO 14230-4 KWP (fast init, 10.4 kbit/s)
- SAE J1850 PWM (41.6 kbit/s)
- SAE J1850 VPW (10.4 kbit/s)
- ISO 9141-2 (5 baud init, 10.4 kbit/s)
- SAE J1939 (250kbit/s)
- SAE J1939 (500kbit/s)
To put it simply, ELM327 is compatible with practically all OBD2 cars that are made or sold in the US. So, as long as your car is not a 1995 or older model you may use an ELM327 adapter for its diagnostics.
Best ELM327 Adapter Reviews
1. Vgate iCar2 WiFi
[for iPhone, iPad, Android, Windows]
The Vgate iCar2 is a best-in-class Wi-Fi adapter that supports not only most US cars but also European and Asian vehicles. With real-time engine data reading and a long list of visible statistics within the mobile app, iCar2 is worth a look.
If you do not want to be scammed by shady mechanics, the interface can help you take a quick look at problems with your car. To top it off, the plug-and-play mechanic makes it straightforward for owners to set up the device with their Wi-Fi enabled phones.
- Plug and Play compatibility
- Supports a suite of third-party apps
- Can read thousands of DTCs and manufacturer-specific codes
- Compatible with iOS and Android
- One Year Replacement Warranty
- Not compatible with heavy trucks
- Wi-Fi coverage drops off at long distances
The iCar2 is one of the best plug-and-play ELM327 interface adapters that allows you to diagnose problems with your car engine efficiently.Check Price at Amazon
2. OHP ELMconfig Forscan
[for Ford, Mazda, Lincoln, and Mercury Car Diagnostics on Windows]
The OHP ELMconfig Forscan OBD2 is one of the best adapters for Ford, Mazda, and Lincoln owners. Even though the adapter is compatible with cars and light trucks only, it covers almost the entire lineup of all three manufacturer’s offerings in the industry since 1998.
Even though the ELMConfig Forscan OBD2 adapter does not support Bluetooth or Wi-Fi, you get a very consistent 500kbits/s of connectivity. The operating speeds are more than sufficient, making it one of the best USB adapters available right now.
The DIY diagnostic tool can be used to diagnose a large number of problems that are commonly seen in car engines. If you want to configure the as-built data of your car, you can do that as well with the vast customization features.
- Seamless setup with Forscan, FoCCUS and other popular software
- Compatible with all cars and light trucks from Ford and Mazda
- Access to all modules
- Supports all US models since 1996
- Live data management
- No Bluetooth or Wi-Fi Support
- Not compatible with heavy trucks
The OHP adapter is specifically geared towards the owners of Ford, Mazda, and Lincoln owners. If you own a car from any of the three listed manufacturers, you should consider acquiring an ELM327 interface by OHP for DIY diagnosis.Check Price at Amazon
3. ELM327 Mini
[for Android/Windows Devices]
Mestart ELM327 Mini Interface Bluetooth Adapter is perfect for OBD2 and EOBD cars. The Bluetooth technology in the device makes connectivity a breeze with no need for additional wiring. The ELM327 Mini Interface device also boasts of reliable Bluetooth coverage.
Usability is something the manufacturer prioritized when creating the Bluetooth adapter. Plug the device into your car’s OBD2 port, fire up Bluetooth, and you are ready to connect.
The adapter displays critical sensor data like engine speed, airflow, fuel pressure, and more.
- Wireless connectivity
- Multi-Protocol Support
- Tracks Long Term Fuel Trim
- Fuel System Diagnosis
- Displays Absolute Throttle Position
- Not compatible with iOS
- Connectivity issues on some cars
- Torque Pro
- OBD Car Doctor
Mestart Bluetooth Adapter is ideal for anyone who is looking for an affordable ELM327 Interface device for Android. It can be used for diagnosis and monitoring your car’s systems.Check Price at Amazon
4. Foseal Wifi Adapter
[for Android and Windows Devices]
Foseal’s Bluetooth OBD2 Adapter is capable of reading error codes that may arise out of problems in your car. Users can monitor current sensor data and check for underlying issues before consulting a mechanic.
The high-quality adapter is compatible with all gasoline vehicles that support OBD2. However, diesel vehicles, hybrids, and trucks with 24V voltage or higher are not compatible with the adapter.
The Foseal adapter is compatible with Android and Windows devices but does not support iOS. You can use it to check engine coolant levels, oil temperature, air flue, speed, and other essential data.
- Over 3000 code definitions
- Displays current sensor data
- Erasable trouble codes
- Oxygen sensor voltage reading
- Vehicle speed monitoring
- Smooth UI
- Not compatible with iOS
- Low wireless coverage
- Torque Pro
The Foseal Bluetooth adapter is ideal for DIY mechanics and car owners alike. You can use it to monitor your car for any underlying issues that need addressing.Check Price at Amazon
5. FOXWELL FW601
[for iPhone, iPad & Android]
Foxwell FW601 Wi-Fi based ELM327 adapter is a cost-friendly option for car owners who want a product that is compatible with both Android and iOS. Unlike other Bluetooth options, you need to own a car that was produced in 2000 or after to make use of the Wi-Fi technology.
The Foxwell adapter is capable of working on all vehicles in the USA as long as they are OBD2 compliant and support Wi-Fi. If you are looking for in-depth vehicle analysis, the vehicle analyzer app will let you identify and diagnose problems instantly.
To get started, all you need to do is download the mobile app and pair it with your adapter. It is much better than most other car adapters available mostly because of its usefulness and pool of features.
- Works with most vehicles released in the US
- Wi-Fi coverage is great
- Vehicle Analyzer app allows in-depth analysis
- One-year warranty
- Works on both Android and iOS
- Does not support Bluetooth
- Compatibility limited to cars from 2000 or later
- InCarDoc Pro
If you are looking for a Wi-Fi adapter that supports most popular vehicles and is easy to set up, the Foxwell is one of the best choices available for consumers. The feature-rich mobile app is user-friendly, and the setup process is a breeze.Check Price at Amazon
How To Use ELM327 Interface
Although you may find some ELM327 interfaces that differ in shape, size, and design, they generally follow the same procedure for connection and use. Start by plugging your ELM327 adapter to your car’s OBD2 port.
From there connect the interface to your phone, tablet or PC. The older ELM327 adapters use a serial port but newer models use either Wi-Fi, Bluetooth or USB. Later on I’ll explain more on these connections and the pros and cons of each.
Make sure that the phone, tablet or PC that you’re using already has anELM327 app or ELM327 software installed. These are basically OBD2 apps or software that help you run diagnostics. I’ll talk more about them as well, so read on to find out how they work.
Once you have made those two connections (to the car and to your computer device) run the OBD2 application. Next, start the car’s ignition and ensure that the engine indicator is lit (on the dashboard). Most ELM327 software will connect automatically or at least they will ask you to connect.
From there you can start collecting data from the ECU while viewing them on your phone or PC. Be sure to observe the LEDs on the ELM327 adapter.
The red LED indicates that the adapter is powered on. On the other hand, the yellow LED is referred to as Tx OBD. It flashes to indicate that there is data transfer from the ELM327 interface to the car’s ECU and from the computing device to the interface. When the green LED (also known as Rx OBD) flashes it indicates that there’s data transfer from the ECU to the interface. It also flashes when data are transmitted from the interface to the computer device.
OS Compatibility of ELM327 Adapters
|Windows (PC) Software||Mac OS Software||Android App||iOS App|
|ELM 327 Bluetooth||✓||--||✓||✓|
Are There Drawbacks To Using ELM327?
ELM327 interfaces are generally cost-effective and easy to use. As a matter of fact they give fully-fledged scan tools a serious run for their money what with their ability to display handy data like codes, PIDs, live sensor data etc.
However, ELM327 interfaces don’t always make the ideal choice. For example, they must be paired with a mobile device or PC to work. If you would rather have a stand-alone scan tool then ELM327-based tools won’t be your favorite.
Besides, they only work with OBD2 vehicles. That locks out all car owners, enthusiasts and technicians who own or frequently work on OBD1-compliant cars.
FAQs About ELM327
- How do I pair my ELM327?
Start by plugging the ELM327 adapter to your car’s OBD2 port. Turn the ignition on without starting the engine. Go to your phone or tablet and turn Bluetooth or Wi-Fi on (depending on which of those the ELM327 interface uses). Search for the adapter and connect with your phone to pair. Note that the name of the adapter depends on its make and model.
- How do I get ELM327 to work?
Make sure your car’s ignition is on. Pair the scanner with your computing device that has a diagnostic app/software. It will automatically communicate with the ECU and display diagnostic data via the app/software.
- Can I upgrade my ELM327 version?
No, you cannot. If you want a newer version you have to buy a new ELM327 interface.
- My ELM327 adapter’s power light keeps flashing and it won’t connect with my phone. What do I do?
The interface is defective. Return for replacement or buy a new interface.
- Where should I buy my ELM327 interface?
Check the recommendations we have given above and pick an ELM327 interface that suits your needs.