OBDII UK: Troubleshoot Car Problems Yourself with a Budget OBD2 Scanner

Dealing with persistent car issues can be incredibly frustrating, especially when garages struggle to pinpoint the problem. Like many UK car owners, I recently faced a recurring error code in my car. The garage diagnosed it as an air conditioning fault, despite my car not even having AC! Frequent trips to clear the code were inconvenient and time-consuming. That’s when I decided to take matters into my own hands and explore the world of On-Board Diagnostics (OBD). For a small investment in a USB OBD connector from a site like Obdii Co Uk, I discovered I could diagnose and clear these codes myself using free software on Linux. This guide will walk you through installing and using this software, empowering you to understand your car’s health.

Understanding OBDII in the UK

Since 2004, European Union regulations have mandated that all cars must feature a standardized connector for On-Board Diagnostics. This was further refined in 2007, stipulating that all vehicles have an easily accessible OBD-II connector, located within 0.61 meters of the steering wheel. Even my older 2004 Ford Fiesta has one, discreetly hidden behind a small flap beneath the steering wheel.

These OBD-II connectors are available in both USB and Bluetooth versions. While high-end, expensive models exist, budget-friendly options, often from Chinese manufacturers, are readily available on sites like obdii co uk and other online retailers. I opted for an affordable generic USB model from Amazon UK, costing around £6. Although delivery took a little longer, it has proven to be perfectly functional for my needs.

Setting up Scantool on Linux for OBDII Diagnostics

For Linux users, like myself running Kubuntu, there’s excellent free software called Scantool that makes diagnosing car issues straightforward. Installation is remarkably simple as it’s included in the Ubuntu Universe repository. Just use these commands in your terminal:

sudo apt-get update
sudo apt-get install scantool

To allow Scantool to communicate with your OBD device, which is typically located at /dev/ttyUSB0, you need to grant your user access to the dialout group. This is because the device file is owned by root and the dialout group. The correct method to achieve this is to add your user to the dialout group, for example:

sudo usermod -a -G dialout sam

While some online guides might suggest running Scantool with root privileges using sudo, this is not recommended and violates the principle of least privilege. Scantool doesn’t require superuser permissions; it only needs to read data from the OBD interface. Running it as root is a lazy and insecure approach – avoid doing this!

Using Scantool to Read and Clear Car Fault Codes

To apply the group membership changes, you’ll need to log out and back into your Linux session. Alternatively, the newgrp command provides a quicker way to use the new group immediately. It changes your current group ID to the specified group, in this case, dialout:

newgrp dialout

Verify that you are now in the dialout group by running the groups command:

groups

You should see dialout listed among your groups. Now, switch on your car’s ignition (no need to start the engine), and launch Scantool by typing scantool in the terminal:

scantool

The Scantool main menu should appear:

Selecting “read codes” will display any error codes stored in your car’s computer, along with descriptions of their potential meanings. OBD-II codes are standardized, but manufacturers sometimes have specific interpretations, so you might see multiple explanations for each code.

If you understand the code and are confident in clearing it, you can choose the “clear” option. Important warning: I am not a qualified mechanic. If you are unsure about the meaning of any codes, consult a professional mechanic before clearing them, and only clear codes if you are certain it is safe to do so.

Returning to the main menu and selecting “sensor data” allows you to view real-time data from your car’s sensors. The engine needs to be running for this feature to work correctly.

Although the “tests” option is not implemented in this version of Scantool, the software still provides ample functionality for basic car diagnostics and troubleshooting. With a cheap OBD2 scanner from obdii co uk and free software, you can gain valuable insights into your car’s health and potentially save money on garage visits for minor issues.