You park your car after a long day, and there it is again. That orange engine light on your dashboard is on. Last time, you drove it to the garage, where you quickly spent a hundred euros just to have it read out what was wrong. The repair was on top of that. And that question lingers. Was it worth it, or could you just as well have discovered it yourself with a cheap OBD2 device? Yet the step to owning your own diagnostic tool for your car is confusing for many people because the range is enormous. From a simple OBD2 for twenty euros to a professional tablet costing thousands: where do you start? In this guide, we take you through it calmly. Whether you want to read and erase fault codes or simply find the best OBD2 scanner to buy: we explain what a diagnostic tool does, the different levels, and what to watch out for, so you choose the right device for your car in one go.
What is an OBD2 scanner?
An OBD2 scanner, also called a diagnostic tool or scan tool, is read via the OBD2 port of your car. This is the universal 16-pin connector that you find under the dashboard on the driver's side in almost every modern car. When you connect the device, it links to the car's onboard computers and shows what is going on: stored fault codes, live sensor values, and, depending on the model, the ability to erase faults or control systems.
Since 2001 (gasoline) and 2004 (diesel), the OBD2 port has been mandatory within the EU. As a result, a diagnostic tool basically works on almost every passenger car made after those years. The big differences are not in whether you can connect, but in how deeply you can look. And that is exactly where the models vary greatly.
What can you do with a diagnostic tool?
Basically, it comes down to this: you read the fault codes that caused the engine light to come on, and you erase them after performing a repair. For many people, that is enough to understand why that light suddenly turned on.
One step further, you can watch the car live. Values such as the engine speed, engine temperature, and fuel pressure appear in real-time on your screen, which is indispensable for faults that only occasionally occur. The better devices also read systems outside the engine, such as ABS, airbags, transmission, and climate control, and assist you with service functions like resetting a maintenance interval or releasing the electronic handbrake for brake pad replacement. On a professional level, it goes even further, with module coding and key programming.
One thing is important to remember, and honestly, many people forget it: a fault code tells you which system is deviating, but not automatically what is broken. The correct interpretation remains human work. That is exactly where the value of a good device lies: it gives you the information to draw the right conclusion yourself.
What to look for when choosing?
The most important question is which cars you want to diagnose with it. European brands like Volkswagen, Audi, Mercedes, and BMW require different coverage than American or Asian models, so always check if your brand is well supported. Also consider how deep you want to go: is reading just the engine enough, or do you also want to access ABS, airbag, and transmission with the associated service functions?
At least as important, and often overlooked, are software updates. A diagnostic tool is only as good as its latest update. So pay attention to how long you get free updates, so your device still recognizes the newest models in two years. If you plan to program keys or modules, choose a device that can handle that right away, as upgrading later is rarely possible.
Finally, two practical matters make a difference. A Dutch-language menu is much more pleasant, especially if you don’t work with diagnostic equipment daily. And buy your diagnostic tool from an official distributor: this ensures genuine software, valid updates, and warranty. Grey imports are often cheaper but will let you down when you want to update.
The best brands: Autel, Launch, and Topdon
If you want to buy a diagnostic tool for your car, you quickly come across three brands. Launch is known for a strong price-quality ratio and extensive OEM diagnostics, often with a generous update package. Autel is the premium, versatile brand excelling in programming and immobilizer functions, making it a logical choice for professional workshops. Topdon is affordable and user-friendly, performing especially well on European vehicles, making it a great starting point. You can find all three with us: Launch, Autel, and Topdon.
The best diagnostic tool for beginners
Do you mainly want to read and clear fault codes and occasionally check some live data? Then an entry-level diagnostic tool is more than sufficient. These three OBD2 scanners are a great starting point:
View the TopScan Master → 
View the MaxiAP AP200 → 
View the ArtiDiag600 S →
For the advanced user
Do you also want to read ABS, airbag, and transmission data, view live data in graphs, and perform service resets? Then choose a more advanced diagnostic tool. These three offer that extra depth:
View the CRP919X BT → 
View the MaxiCom MK900 → 
View the One Lite →
For professionals and workshops
Need full brand coverage, online programming, and immobilizer functions? These are the complete diagnostic systems built for daily use:
MaxiSys Elite II Pro → 
MaxiCom MK900-TS → 
Topdon One Plus → 
X-431 PAD VII Elite →
Which level suits you? Brief summary
Entry-level · for advanced private users. Reads and clears fault codes, plus basic live data. Recommended: TopScan Master, MaxiAP AP200, and ArtiDiag600 S.
Advanced · for key programmers or small garages. Read all systems, live data, and service resets. Recommended: CRP919X BT, MaxiCom MK900, and One Lite.
Professional · for workshops or specialists. Programming, coding, and immobilizer functions. Recommended: MaxiSys Elite II Pro, MaxiCom MK900-TS, and X-431 PAD VII Elite.
Frequently Asked Questions
Does every OBD2 scanner work on every car?
The OBD2 port is universal from about 2001 (gasoline) and 2004 (diesel), but the depth of diagnosis varies by device and brand. Always check if your car is supported before buying a diagnostic tool.
Can I turn off my check engine light?
Yes, you can read and clear fault codes. But if the underlying issue isn’t fixed, the warning usually returns.
What is the difference between reading and programming?
Reading means retrieving information, such as fault codes and live data. Programming means writing data to the car, like modules or keys, and requires a professional diagnostic tool.
What is the best OBD2 scanner for my car?
It depends on your level and vehicle. For occasional diagnostics, an entry-level model is sufficient; if you want to access all systems and programming, choose an advanced or professional device. See the recommended options by level above.
Why buy a diagnostic tool from AsTools?
We are distributors of Launch, Autel, and Topdon, among others. You get original software, valid updates, warranty, plus advice from real workshop experience.
Ready to choose your diagnostic tool?
Choose based on the cars you want to diagnose, the depth you need, and the updates included. If you’re unsure, we’re happy to help. View all diagnostic tools →
Unsure which diagnostic tool fits your car? Contact our customer service →. Order before 4 PM today for same-day shipping, and as an official distributor, we provide warranty and original software updates.