Choosing the right ELM327 OBDII/OBD2 Bluetooth adapter is crucial for effectively using car diagnostic apps like Car Scanner. This adapter acts as the communication bridge between your smartphone or tablet and your car’s control unit. Selecting a high-quality adapter ensures a stable connection and reliable access to your vehicle’s data.
If you’re looking for quick recommendations on which adapter to buy and where to find them, feel free to skip ahead. However, understanding the nuances of ELM327 adapters will empower you to make an informed decision.
Understanding ELM327 Adapters
When selecting an ELM327 adapter, two key aspects come into play:
- Compatibility with your device: The adapter must be compatible with your smartphone or tablet’s operating system. This largely depends on the connection type the adapter utilizes.
- Adapter Quality: The adapter should be of high quality, performing its function reliably without glitches or errors.
ELM327 Adapter Connection Types
ELM327 adapters connect wirelessly to your devices, and are broadly categorized by their connection type:
- Wi-Fi: Adapters using Wi-Fi connect to your device like any other Wi-Fi network.
- Bluetooth Classic (Versions 1.x, 2.x, 3.x): These are traditional Bluetooth connections, widely supported by Android devices.
- Bluetooth Low Energy (LE) (Version 4.0 and above): Bluetooth LE is designed for low power consumption and is essential for iOS devices. Despite the name similarity, it’s a different communication method than classic Bluetooth.
- Bluetooth MFi: This is classic Bluetooth specifically certified by Apple for use with iPhones and iPads. These adapters require manufacturers to have an agreement with Apple, making them less common and typically more expensive. Examples include OBDLink MX+ and vLinker FS. On Android, they function as regular Bluetooth adapters.
- USB: USB connections are not supported by Car Scanner, which focuses on wireless OBDII adapters.
The ideal connection type depends primarily on your smartphone or tablet’s operating system.
Choosing an ELM327 Adapter for Apple iOS (iPhone/iPad)
For Apple iOS devices (iPhone/iPad), Car Scanner supports Bluetooth LE (4.0), Wi-Fi, and Bluetooth MFi adapters. It’s critical to note that classic Bluetooth adapters (versions 1.x, 2.x, 3.x) are NOT compatible with iOS due to operating system limitations. This is a fundamental restriction of iOS and applies to all apps, not just Car Scanner.
Recommended Connection Type for iOS: Bluetooth LE (4.0).
Bluetooth LE adapters offer the best balance of ease of connection, acceptable data transfer speeds, and availability. While Bluetooth MFi adapters provide top-tier performance, they come at a premium price. Wi-Fi adapters can be problematic, often leading to connection issues and potentially disrupting your mobile internet connection.
Bluetooth Version is Crucial for iOS! Many iOS users mistakenly purchase classic Bluetooth adapters, only to find they are incompatible with their iPhones or iPads. This limitation is due to the iOS architecture itself and cannot be circumvented by any app.
Choosing an ELM327 Adapter for Google Android
Google Android devices offer broader compatibility, supporting classic Bluetooth (versions 1.x, 2.x, 3.x), Bluetooth LE (4.0), and Wi-Fi adapters. For Android, classic Bluetooth adapters are generally recommended. They offer faster speeds than Bluetooth LE and are typically more reliable than Wi-Fi for OBDII connections. A vast majority (95%) of Android users successfully use classic Bluetooth ELM327 adapters.
However, a potential drawback with classic Bluetooth on Android is that some devices may experience issues when connected to multiple Bluetooth devices simultaneously, such as an OBDII adapter and a car’s Bluetooth multimedia system.
ELM327 Adapter Quality: Beyond Versions and Chips
Forget outdated advice about specific ELM327 versions, chips, or circuit board counts. This information is no longer a reliable indicator of adapter quality. The market is flooded with clones, and manufacturers can easily fake version numbers and internal components.
The real distinction lies between “good” and “bad” ELM327 adapters. A good adapter simply works as expected – it establishes a stable connection, transmits data accurately, and doesn’t introduce glitches or freezes. Your primary goal is to identify and purchase a good quality adapter.
Unfortunately, “bad” adapters are prevalent and can cause a range of problems.
Problems with Low-Quality ELM327 Adapters
Using a low-quality ELM327 adapter can lead to numerous issues, including:
- Complete Failure: The adapter may not work at all, failing to connect to your car’s ECU.
- Unstable Operation: Intermittent connection problems such as freezing, spontaneous reboots, or ceasing to function under certain conditions (temperature, humidity). Inconsistent performance, where the adapter works sometimes but not others, or provides varying data sets.
- Limited Command Support: The adapter may not fully support the required ELM327 command set, despite claiming to do so.
- Fixed ECU Address: Some faulty adapters are hard-coded to communicate with only a standard ECU address, preventing connection to other control units in your vehicle.
- Data Length Limitations: Restrictions on the length of data requests and responses, hindering comprehensive diagnostics.
- Data Loss: Incomplete data transmission, where packets are lost during sending or receiving, resulting in corrupted or unusable data.
- Data Corruption: Distortion of data during transmission, potentially leading to incorrect commands being sent to the ECU (e.g., accidentally sending an erase memory command instead of a temperature request).
- Protocol Incompatibility: Limited support for OBDII communication protocols, making the adapter incompatible with certain car models or systems.
- On-board Network Interference: “Bad” adapters can flood the car’s network with junk data or requests, disrupting the ECU’s primary functions and potentially causing engine roughness or other performance issues.
- Critical Failures in Advanced Functions: For features like “Coding and Service” that involve writing data to the ECU, a high-quality adapter is essential. A poor adapter can lead to data writing failures or, worse, writing incorrect data, which can have severe consequences for your vehicle’s systems.
The Prevalence of Low-Quality Adapters
The market is unfortunately saturated with low-quality ELM327 adapters. It’s not uncommon to purchase multiple adapters and find that none of them function reliably. This makes choosing a reputable adapter a critical step.
Recommended ELM327 OBD2 Bluetooth Adapters
It’s important to note that as a content creator for obd-de.com, and an expert in automotive repair, I do not sell ELM327 adapters directly. The following recommendations are based on extensive testing, user feedback within the Car Scanner app community, and my professional experience. These recommendations are sorted roughly from most expensive to least expensive.
OBDLink MX+ with Bluetooth MFi (#ad link). Price: Approximately $100 USD. Compatibility: iOS & Android. This is the most advanced and feature-rich adapter, offering exceptional performance and reliability.
OBDLink CX with Bluetooth LE (#ad link). Price: Approximately $80-100 USD. Compatibility: iOS & Android. Known for its large memory buffer and excellent overall performance, especially with Bluetooth LE.
vLinker Devices: A reputable brand offering several reliable options:
- vLinker MC+ with Bluetooth LE (#ad link). Bluetooth LE, ideal for iOS and Android.
- vLinker FS with Bluetooth MFi (#ad link). Bluetooth MFi, specifically for iOS, also works with Android.
- vLinker MS with Bluetooth MFi. Designed as a competitor to OBDLink, vLinker MS has improved significantly with firmware updates and is now a solid choice.
For vLinker devices, especially earlier versions, ensure you update the firmware to the latest version available on the manufacturer’s website for optimal performance and bug fixes. Bluetooth for Android and Bluetooth LE for iOS are generally recommended connection types within the vLinker range.
Vgate iCar Pro 2S: A newer and improved version succeeding the iCar Pro BLE. If choosing between these two, the iCar Pro 2S is the preferred option due to its enhanced features and performance.
Vgate iCar Pro BLE (#ad link). This adapter is compatible with iOS, Android, and Windows due to its dual Bluetooth 2.0 + Bluetooth 4.0 chip. Important: Older firmware versions (prior to v.4.1.02 from 2021/01/08) had issues with CAN Extended addressing used in Toyota and BMW vehicles. Firmware updates are crucial. Download the latest firmware for Vgate iCar Pro here.
ELM327 OBD2 Adapters to Avoid
To help you steer clear of problematic adapters, here is a list of brands and types to avoid:
- xTool Adapters: These are not ELM327 compatible and only work with xTool’s proprietary software.
- Wired Adapters (USB, COM): Car Scanner exclusively supports wireless adapters.
- “Mini” Adapters: Adapters with “mini” in their name have a very high probability (99%) of being low quality.
- Extremely Cheap Adapters: Significantly low-priced adapters are often too good to be true and likely to be unreliable.
- Adapters with Bluetooth MAC Addresses Starting with 11:22:33 and 00:00:00: These are often indicators of generic, low-quality clones.
- KONNWEI Devices: While previously recommended, KONNWEI adapters have experienced a decline in quality and frequently exhibit data packet loss.
- “Micro Mechanic” Adapters: Many users report these adapters failing after a short period.
- “THINMI.COM” Adapters: Known for limited ELM327 command support and often providing fake responses.
- KUULAA Brand Adapters: Generally unreliable based on user feedback.
- Adapters with a Specific Design (See Images Below): While compatible in theory, adapters with this compact, often colorful design are frequently of very poor quality.
P.S. Please note that links on this page to Amazon.com are affiliate links. As an Amazon Associate, I earn from qualifying purchases, which helps support the creation of free and informative content on obd-de.com.
