Modern cars are great, except when they go wrong.
The number of computerised electronics in today’s vehicles means that they can be a bit opaque when it comes to diagnosing faults at home, requiring a trip to a mechanic or main dealer.
An OBD scanner is useful here, helping you to find out what the issue is before you drive it to the dealership. It can even lead to home repairs, if you’re feeling confident.
OBD stands for on-board diagnostics, and is essentially a way for a car to tell you what’s wrong with it via a standardised connection and a bunch of error codes. With an OBD scanner, you can plug into your car and get a fault report displayed on its screen. They’re the same tools mechanics use to diagnose car trouble, and can save you precious time and money.
The OBD-II port has been standard on UK cars since 2004, and looks a little like the SCART sockets that used to lurk on the back of TVs. But only a little.
They’re not always in the same place on all cars, and are often hidden behind a panel in the driver’s compartment near the fuses. It’s worth familiarising yourself with the position of the socket if you intend using an OBD scanner, to avoid a frustrating time searching for it when you need it. Here are some of the best.
Best car diagnostic tools at a glance
- Best overall: Draper Fault Code Reader and Oil Reset Tool - £242.32, Electrical World
- Best for good value for money: Motopower OBD2 Scanner - £26.50, Amazon
- Best for something simple: Laser Fault Code Reader - £40, Halfords
- Best for the luxury option: Topdon Phoenix Lite 2 - £829.99, Amazon
- Best for use with phones: XTRONS Car Auto Diagnostic Scanner - £18.66, Amazon
- Best for occasional use: Sarini OBD2 Scanner - £11.99, Amazon
- Best for a versatile approach: ANCEL BD310 OBD2 Scanner - £69.99, Amazon
- Best for deep vehicle insights: Carly Universal Adapter - £99.99, Amazon
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Draper Fault Code Reader and Oil Reset Tool
Best: overall
The Draper Fault Code Reader and Oil Reset Tool is notable not only for its large, easy-to-read screen but for the number of features squeezed in, including Mode 6 diagnostics to provide detailed test results for individual vehicle systems and components, as well as the ability to reset oil change indicators.
It connects using a cable and allows mechanics to see how well specific systems are performing, and can help diagnose issues even before a check engine light illuminates.
As such, it’s also a top-priced model, and you’ll need to be sure you’ll use all or most of its capabilities before you take the plunge.
Buy now £242.32, Electrical World
Motopower OBD2 Scanner
Best for: good value for money
This low-price wired OBDII scanner comes with a decent-sized (though low res) screen and robust build quality.
Compatible with nine different OBD protocols, Motopower’s scanner can help you determine the cause of the fault light, read error codes before clearing them, and view freeze-frame information from the moment the error was triggered.
The Motopower scanner takes its power directly from the data link connector, so there's no need to carry batteries or a charger.
Buy now £26.50, Amazon
Laser Fault Code Reader
Best for: something simple
The Laser’s screen may be small, but it’s backlit to be more easily seen in dark environments and gives you all the information you’ll need - it’s a pure fault code reader, so will display the string of numbers that points you toward the problem in conjunction with a list of codes supplied by the vehicle manufacturer.
It’s a simple wired reader that can also reset warning lights, but doesn’t come with the advanced features of some other OBD scanners.
Buy now £40.00, Halfords
Topdon Phoenix Lite 2
Best for: the luxury option
Very expensive and complex, this device, with its eight-inch colour touchscreen, is a step toward the professional OBD scanners used by vehicle technicians and mobile rescue patrols.
The screen connects wirelessly to a dongle that’s placed in the OBD socket, so you’re not tethered to the scanner and can operate it from outside the vehicle more easily. The Phoenix Lite 2 features bi-directional control over vehicle systems and components, and can perform active tests on parts such as fuel injectors, windows, windshield wipers, and more.
Compatible with over 200 brands of cars, this scanner can help you to quickly locate faulty parts and run full system diagnostics.
Buy now £829.99, Amazon
XTRONS Car Auto Diagnostic Scanner
Best for: use with phones
Distinctively yellow and unlikely to be easily lost in the footwell, this is a connection adapter for iOS and Android devices that can turn your smartphone into a wireless diagnostic scan tool and real-time vehicle monitor. It’s supported by a range of third party apps across both major mobile operating systems, some of which may need to be purchased. With one installed you can read and clear engine light trouble codes, reset the check engine light, view real-time sensor readings and estimate fuel economy.
Buy now £18.66, Amazon
Sarini OBD2 Scanner
Best for: occasional use
Another brightly coloured scanner, this is a basic, and very low-cost, model with a simple interface.
The cable that connects to the diagnostic socket is quite short, so it can be awkward to use in tight spaces, but despite this the Sarini scanner provides all the information you need to make a diagnosis of your car’s problem, and would suit someone who wants a cheap scanner to keep on the garage shelf for those times you really need it.
Buy now £11.99, Amazon
ANCEL BD310 OBD2 Scanner
Best for: a versatile approach
Both a handheld OBD scanner with a screen and a wireless connection to a smartphone app, this versatile device is capable of sending a live feed to your phone (a mount for it is included) so that you can view fuel consumption, battery voltage, RPM and more on a customisable dashboard.
As a standard OBD scanner, it can use freeze-frame data and help determine the causes of fault codes, including performing DTC lookup to find the meanings behind codes without needing to paw through the vehicle manual.
Buy now £69.99, Amazon
Carly Universal Adapter
Best for: deep vehicle insights
A dongle that connects wirelessly to your phone, the price of the Carly varies depending on which brand of car you want to use it with, and comes as an annual subscription rather than a one-off payment, with the connector given away for free when you sign up for a plan.
What you get is a suite of diagnostic tools on top of the basic OBD features, building up a complete picture of your vehicle’s health. It goes further than many other OBD scanners, as it’s able to access real-time engine data, recording and exporting it so you can peruse it later, and can even change settings and unlock hidden features in your car, giving a degree of customisation without needing to get out the welding torch.
Buy now £99.99, Amazon
Verdict
An OBD scanner can be a useful tool if you want to check out what’s wrong with your car before you take it to the mechanic, or if you’re interested in fixing it yourself.
A wide range of different styles is available, but if you’re interested in versatility, one that connects to your phone, such as the XTRONS Car Auto Diagnostic Scanner, make a good choice.
Otherwise, a wired scanner is easy to use, doesn’t require charging or Bluetooth pairing, and can give you all the information you need. For this reason, the Draper Fault Code Reader and Oil Reset Tool is at the top of our list.
