What is an OBD2 Bluetooth Adapter?

Going wireless with OBD-II Bluetooth

OBD2 Bluetooth adapter
This OBD2 Bluetooth adapter is plugged straight into the OBD2 connector, where it can be left during vehicle operation. Photo © Jeremy Laukkonen

If it seems like everything is using Bluetooth these days, that’s probably because just about everything is using Bluetooth these days—and that includes OBD-II scanners. Bluetooth might have originally been envisioned as a competitor for Wi-Fi, but the technology has really really hit its stride in recent years as a computer-to-device wireless network, and hooking your car’s onboard computer into a scan tool definitely fits that bill.

Let’s take a quick look at your options.

Wireless OBD-II Bluetooth Connections

Traditional OBD-II code readers and scan tools use hard-wired connections, but Bluetooth has emerged as an alternative that cuts the proverbial cord. Although there are no traditional scan tools available that use a wireless connection instead of a physical cable and plug, there are a couple of different solutions out there.

DIY OBD-II Bluetooth Adapters

Most OBD-II Bluetooth adapters out there utilize the ELM327 microcontroller, which provides an interface with your vehicle’s onboard computer. Since these adapters include Bluetooth radios, they can be used in conjunction with virtually any Bluetooth-enabled device. Laptops, tablets, smartphones, and other devices can all function as scan tools when paired with an ELM327 Bluetooth adapter.

The main exception is iOS devices, which can’t be paired with just any off the shelf OBD-2 Bluetooth adapter. If you have an iOS device, and you want to hook it up wirelessly to your car’s onboard computer, then you're better off with an OBD-II Wi-Fi adapters than looking for an ELM327 iPhone adapter.

Complete OBD-II Bluetooth Scanners

A handful of companies offer packages that include an OBD-II Bluetooth adapter or dongle, a device like a PDA, tablet, or a laptop, and pre-installed scan tool software. These packages are good for anyone who doesn’t have a compatible device or doesn’t want to mess around with potential incompatibilities or purchasing separate software.

OBD-II Bluetooth Software and Drivers

The functionality of an OBD-II Bluetooth adapter's connection will vary depending on the device you hook up to and the software you have installed. There is free ELM327 scanner software available for platforms like Windows and Android, but premium software typically offers additional functionality and more advanced features.

Devices that are equipped with Bluetooth typically won’t require any additional drivers in order to hook up to an OBD-II Bluetooth adapter. The process of pairing this type of adapter is similar to pairing a headset or any other Bluetooth device, so it is relatively straightforward.

Counterfeit OBD-II ELM327 Bluetooth Devices

Some low-cost OBD-II Bluetooth adapters use unofficial ELM327 microcontrollers that are based on pirated specifications rather than official ELM electronics components. These microcontrollers sometimes fail to work properly due to poor quality control, and they also lack the tweaks and improvements seen in official ELM327 microcontrollers that are produced under license and according to updated specifications. So before you buy an OBD-II Bluetooth adapter, it pays to check into whether or not it has a pirated chip.