One of the cheapest fault code readers (FCR) is a small device that plugs into the on-board diagnostics port of a vehicle and not only communicates with the ECU, but also with an app on a smartphone or laptop. Most of these devices connect to an EOBD port, which means they are compatible with European petrol engine cars from 2001 onwards and diesels from 2004 to the present. However, they are also compatible with US vehicles from around 1996 onwards.
The six devices we are testing all plug into a vehicle’s EOBD port and communicate with a smartphone or Windows-based PC or laptop via a Bluetooth connection. It’s worth finding out whether your phone or computer is suitable before purchasing one of these devices because, in some cases, the version of Bluetooth may be too old, the smartphone may not be suitable (including its operating system) or the version of Windows (most are for Windows 7-10).
This is probably where the most confusion exists because some of the devices we have tested can be used with several third-party apps, so it’s difficult to pick a winner that meets your exact needs. Many apps are generic, but some, such as BimmerCode, cater for BMWs and several MINIs. To help, we’ve listed the apps that can be used with each device.
HOW WE TESTED THE BLUETOOTH FCRs
We had a couple of vehicles ready and waiting to test the Bluetooth FCRs on – a 2005 Audi A3 Sportback with a 2.0-litre diesel BKD engine, and a 2006 Ford Focus with a 1.6-litre Duratec petrol engine. We knew the Audi had a parking sensor issue, although we didn’t expect every FCR to find this as some are only intended for diagnosing
