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What is a car diagnostic scan tool?

With a car diagnostic device, you can read and display all the data and error codes from the control units and onboard electronics of your vehicle. With many modern car diagnostic devices, it is possible to correct the errors and clear the error code accordingly. You simply connect the scan tool to the designated interface in the car and the error analysis often starts automatically.

With an automotive diagnostic scan tool, all the data and error codes of the onboard electronics can be displayed in real-time. The user then receives an appropriate diagnosis. In addition to fault codes, diagnostic devices also read engine data such as coolant temperature and fuel consumption.

A diagnostic device can also be used to edit fault codes when they have been corrected or should no longer be displayed. A good example of this is the service indicator, which often bothers drivers. The diagnostic scan tool gets their data from OBD (on-board diagnostics), which is connected to the car’s control units. With a car diagnostic device, some garage visits or rip-offs can be avoided. The scan tool prepares you to diagnose your car correctly, so you don’t end up paying for repairs your car doesn’t need.

What are the benefits of a diagnostic scan tool?

A car scanner is suitable for every car owner. With such a car diagnostic scan tool, you can find faults independently and quickly, saving you from hours of fault analysis at the garage, which can sometimes result in a high bill. Even on vacation, a car scanner can be a lifesaver, so you don’t have to go on a stressful search for the nearest repair shop.

Is it possible to diagnose all makes of cars?

Yes, but of course it depends on the scan tool. Not all devices can work with all manufacturers. The diagnostic scan tools that can diagnose almost any car are often really professional devices and correspondingly expensive. So you have to think carefully about what exactly you need. As a workshop, of course, you need as wide a range as possible. As a private user, the most common models or even a special app for just one manufacturer can suffice.

The most important facts in brief

  • If your car’s onboard system reports an error, you can use the automotive diagnostic device to read out the exact cause. Either you still have to look up the received error code or the device shows you its meaning directly.
  • Thanks to the mandatory standard OBD-2 (on-board diagnostics), all vehicles use the same interface and comparable software, so the devices work with different types and models. However, if your gasoline engine is registered before 2001 or your diesel before 2004, you will need a manufacturer-specific diagnostic device.
  • Many inexpensive automotive diagnostic devices do without a screen. The information is then available in a notebook or even easier on your smartphone. The software used has a great influence on the functions available to you.

Do the different types of automotive diagnostic scan tools have a screen?

There are two types that differ significantly from each other by the presence or absence of a display. What they all have in common, of course, is that they are standardized OBD2 automotive diagnostic devices, all of which can be connected to the interface in your car.

Variant features

With screen:

  • the device can be used alone;
  • ready for immediate use with installed software;
  • error codes and error descriptions are displayed directly.

Without screen:

  • notebook or smartphone necessary;
  • connects via Bluetooth or USB;
  • additional software must be installed;
  • usually much cheaper than models with screen.

Diagnostic scan tools – Best Choice

Best choice

ANCEL Vehicle OBD2 Scanner

Not only diagnose the engine system but also performs full detection on vehicle’s other 3 main ECU systems (Transmission, ABS, Airbag(SRS)). Reads & erases fault codes, turns off warning lights, and reads live PCM datastream on these 4 systems.

5,0 Rating
Reads fault codes for the check engine light, both generic and manufacturer specific codes.
Erases fault codes.
Retrievies vehicle information (VIN).
Advanced On-board monitoring test.
Full OBD II modes for 2005 & newer vehicles.

How to choose diagnostic scan tool for your car

Best 5 diagnostic scan tools


ANCEL Vehicle OBD2 Scanner

ANCEL Vehicle OBD2 Scanner
  • Read dynamic live datastream, able to store and playback.
  • Support lifetime free upgrade online via a PC.

4,9 Rating

Check Best Price


BlueDriver Bluetooth Pro OBDII Scan Tool for iPhone & Android

BlueDriver Bluetooth Pro OBDII Scan Tool for iPhone & Android

  • Show each data source as a Graph, Gauge, or Digital Display
  • Advanced test results

4,9 Rating

Check Best Price


OBDLink MX+ OBD2 Bluetooth Scanner for iPhone, Android, and Windows

OBDLink MX+ OBD2 Bluetooth Scanner for iPhone, Android, and Windows

  • ABS, SRS, TPMS, A/C, transmission temperature, and wheel speeds.
  • Rock-solid connection: no dropped packets, no gaps in the data

4,8 Rating

Check Best Price


LAUNCH OBD2 Scanner Tool

LAUNCH OBD2 Scanner Tool

  • Tests Engine, Transmission, ABS and Airbag, and others.
  • Graph, record, and replay data in full color.

4,5 Rating

Check Best Price


FOXWELL Obd2 Car Code Reader Vehicle Diagnostic Scan Tool

FOXWELL Obd2 Car Code Reader Vehicle Diagnostic Scan Tool

  • All function scanner.
  • 2.8” TFT color screen.

4,5 Rating

Check Best Price

We have tested best diagnostic scan tool and selected the best products for you

What are the most important features of automotive diagnostic scan tools?

No car diagnostics device test can do without a close look at individual features. In the following, the most important facts about the general importance of the features are compiled so that you can make the best choice for yourself when buying the car diagnostic device.

The right car types: For all brands or just one manufacturer

Since the control system is required by law and standardized accordingly, car diagnostic devices use OBD2 to communicate with your car.

The interface is mostly found near the fuse box and is always designed the same way. Problems arise only with old cars before 2004, because the introduction of the system was so:

  • 2001 for gasoline.
  • 2004 for diesel.

If your car is older, you can not use the standard models. Previously, manufacturers used their own technology to monitor the electronics of the car.

Additional equipment simplifies handling: Practical connections for data transmission

Especially in the case of automotive diagnostic devices with a screen that uses permanently installed software, you should pay attention to a practical interface. With a card slot for SD cards or a USB connector, this allows you to transfer new information.

Every year, new models of vehicles appear, and with a suitable update, you thus ensure that the device is always up to date.

This is less of a problem with automotive diagnostic devices with Bluetooth, as the software update takes place directly on the smartphone accordingly. The same also applies to automotive diagnostic devices with a laptop connection. Depending on the software you choose, the update can be performed when you have access to the Internet.

How to use the car code reader

As soon as an indicator lamp lights up in the cockpit, you can use a car diagnostic device to read out the fault yourself and rectify it if necessary or visit a workshop. A diagnosis is carried out as follows:

  • OBD port: the OBD port is not always located in the same place in the car. However, in principle, it can be said that it is located near the steering wheel. If you don’t feel like searching or can’t find the interface, you can find it in the car’s manual.
  • Connect the car diagnostic device: once the OBD interface of the car is found, the diagnostic device can be connected to the car. Depending on the model, this can be done via cable or Bluetooth.
  • Readout fault codes: After you connect the diagnostic device to the car, it should read out a fault code. Some models will translate the code directly for you, showing you the problem immediately. If only the plain code is displayed, you will have to translate it yourself.

David Muench (Carnes Mechanical)

David Muench (Carnes Mechanical)

Hey, I’m David. I’ve worked in a cars store for 6 years. I write reviews and guides, helping people to choose the most suitable technicals and best product for them. I’m happy to finally share my knowledge of the industry here, on CarnesMechanical.

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