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Affordable bi-directional scan tool 2021: Why pay a lot if you can pay less?

Every car owner knows the value of OBD2 scanners in-home diagnostics and repair. For deeper diagnostics and more complex repairs, though, you’ll need a bi-directional scan tool. The best bi-directional scan tool allows you to conduct more detailed tests than other options.

You might think you’ll have to spend a fortune for a bi-directional scan tool, but the truth is some of them are very affordable. This puts these handy tools in the reach of those looking to do DIY repairs, not just professional garages.

Ready to get one for yourself? Check out the full reviews of the 9 best bi-directional scan tools below to find the perfect new tool for your garage.

What Is A Bi-Directional Scan Tool?

All scan tools can read and clear diagnostic trouble codes. A bi-directional scan tool, however, allows you to send direct commands to your vehicle’s control modules, as well as receiving feedback. This two-way communication opens up an array of powerful customization and repair features.

You might be wondering how this could be useful in your life. The main advantage of a bi-directional scan tool is it allows you to conduct a more comprehensive diagnosis. By manually activating solenoids and other components, you can be certain which ones work and which ones don’t. Trouble codes only point you toward the problem, so bi-directional scan tools are far more specific.

Bi-directional scan tools also typically give you access to a wider range of systems than standard OBD2 readers. Most will at least let you reset the oil light, airbag light, and parking brake light. More extensive models provide access to every electronic system, including climate control and lights.

Best Bi-directional Scan Tool Comparison Chart

All of the scanners on this list offer full OBD2 functionality and comprehensive diagnostic features. The main difference between the best bi-directional scan tools comes in their special functions. Let’s compare three of the top models side by side so you can see what we mean.

Editor's PickBest CheapAlso Great
Launch X431 Diagun IV
Launch X431 Diagun IV
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Autel DS808
Autel DS808
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Launch CRP429
Launch CRP429
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Customer Rating
PriceLAUNCH X431 DIAGUN IV priceAutel Maxidas DS808 priceLAUNCH CRP129X price
Vehicle Makes Supported108 manufacturers
80+ manufacturers50+ manufacturers
Oil/SRS/EPB ResetYes
SAS CalibrationYesYesYes
TPMS RelearnYesYesYes
ABS BleedYesYesYes
DPF RegenerationYesYesYes
BMS ResetYesYesYes
Gear LearningYesNoYes
IMMO/Key ProgrammingYesNoNo
Make New KeysYesNoNo
Fuel Injector CodingYesYesYes
ECU CodingYesNoNo

Bi-directional Scan Tool Reviews

1. Launch X431 Diagun IV Bidirectional Control Scan Tool

Launch scanners are powerful diagnostic tools, and the Launch X431 Diagun IV is arguably the best bi-directional scan tool in their line.

LAUNCH X431 DIAGUN IV Bidirectional Control Scan Tool
With a full range of reset and coding functions, the Launch X431 Diagun IV goes beyond basic diagnostics, making it the ideal DIY repair companion.

Diagnostic and actuation tests

As a diagnostic tool, OBD2 is just the start of what the Launch X431 can do. The range of module tests in the Launch X431 Diagun IV is impressive. You can conduct active testing on the purge control solenoid, fuel pump, clutch, and a host of other major electronic systems. All diagnostic reports can also be printed through a PC.

A mechanic might find some tests are absent from the Launch X431 Diagun. For DIY repairs, though, it has everything you need to avoid a trip to the mechanic. Reading fault codes for all electronic systems, even the wipers, and lights gives you powerful insight into your engine. 

 Launch X-431 Diagun IV can perform 10 updated special functions.
 Launch X-431 Diagun IV can perform 10 updated special functions.

Reset and programming functions

Moving on to the repair functions, the Launch X431 Diagun starts with 11 reset functions. No matter which warning light is pestering you, the Launch X431 will help. Included in this are important repair services like ABS bleed and DPF regeneration.

The coding functions of the Launch X431 Diagun are plenty for any home repair. Most importantly, it offers key programming and IMMO reset. You can also relearn gears or TPMS and gain full control of your fuel system. Only professional mechanics will note the absence of some higher-level coding functions.


  • Full system diagnosis capability
  • Live data graphing makes diagnosis easier
  • Supports 11 reset functions
  • Easy to perform actuation tests
  • Capable of programming keys and resetting IMMO system
  • Extensive coverage of over 100 manufacturers
  • One-click update option


  • ECU coding functions are a bit limited
  • Requires a PC for printing diagnostics

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A video of Launch X431 Diagun IV

2. Ancel AD610 Elite Bi-directional Scanner

The best bi-directional scan tools can sometimes cost a pretty penny. For bi-directional control on a budget, though, the Ancel AD610 has all you need.

ANCEL AD610 Elite Bi-directional Scanner
Ancel AD610 ’s the most affordable hand-held scanner you’ll find with the ability to activate components and actuators. .

Diagnostic power

The Ancel AD610 supports all 10 OBD2 test modes. In addition, it can read and clear trouble codes on OBD1 systems, expanding its versatility. While it doesn’t have the full system diagnostics of pricier scanners, it does give access to ant-lock brake and airbag systems.

All live sensor data read by the Ancel AD610 can also be recorded and stored. Adding in the auto-VIN capability and the enhanced Mode 6 testing, and you get an OBD2 scanner that far exceeds its price point.

Reset and control functions

Admittedly, the repair functions of the Ancel AD610 are a bit limited compared to other scan tools reviewed here. The main options are SRS and ABS reset, though it can also calibrate SAS for about half the supported manufacturers.

As far as bi-directional control, it’s predominantly focused on those same systems. While this control isn’t robust, the features it does offer are easy to use, even for non-experts. This makes the Ancel AD610 a powerful tool for home automotive repair.

ANCEL AD610 Elite is used for reading and erasing ABS & SRS light trouble codes on most OBD2 vehicles.
ANCEL AD610 Elite is used for reading and erasing ABS & SRS light trouble codes on most OBD2 vehicles.


  • Most affordable option
  • Works with both OBDII and OBDI diagnostics
  • Reads and clears ABS and SRS trouble codes
  • Allows activation and control of many electronic components
  • Compatible with over 60 manufacturers
  • Free to update


  • Can’t read all non-OBD2 systems
  • Reset functions not supported for all vehicles

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A video of ANCEL AD610 Elite

3. Autel Maxidas DS808 Automotive Diagnostic Tool

If you know OBD2 scanners, you know the name Autel. They make some of the best bi-directional scan tools on the current market.

 Autel Maxidas DS808
Autel Maxidas DS808 Automotive Diagnostic Tool
The Autel Maxidas DS808 is a great choice for both home mechanics and repair professionals.

Advanced diagnostics

The Autel DS808 can diagnose all trouble codes, both OBD2 DTCs and those for non-OBD electronic systems. In addition, you can read information from the ECU that other hand-held scanners don’t access.

Professional garages will make excellent use of the shop manager feature of the Autel DS808. It makes organizing and retrieving stored diagnostics easier than ever. Hot service functions give quick access to the most commonly used features, which is another helpful time saver.

Special Functions

Among the reset functions of the Autel DS808 are common ones like EPB, TPMS, and the oil light—over 10 functions in all. You can also control the DPF regeneration and SAS calibration.

The only place the Autel DS808 might fall short for a professional mechanic is in the coding functions. While it can retrieve information from the ECU and perform active tests, you can’t reprogram the ECU with this bi-directional scan tool, or make new keys. Having said that, though, these aren’t functions you’ll likely miss as a DIY mechanic.

 Autel DS808 offers exceptional functionality.
Autel DS808 offers exceptional functionality.


  • Includes all common reset and diagnostic functions
  • Supports active testing, adaptation, and matching
  • The interface is intuitive and easy to navigate
  • Smart AutoVIN and hotkeys speed diagnosis and repair
  • Shop manager function helps you keep track of data
  • Auto-update option directly through the scanner


  • Not capable of programming keys
  • ECU programming features are limited

Check Price at Amazon

4. Launch CRP429 OBD2 Scanner

Another great option for the budget-conscious is the Launch CRP429. You’ll get the same build quality and intuitive navigation you’ll find on more expensive Launch scanners—as well as an impressive range of features for the price.

  Launch CRP429
Launch CRP429 OBD2 Scanner
The Ancel AD410 is a great tool for beginners.

Diagnostic Features

The Launch CRP429 supports full OBD2 testing and diagnostics. For reading trouble codes, you can see live data from any system, including non-OBD2 electronic systems. This diagnostic power can be applied to the majority of popular brands, too, so it’s perfect for home garage repair. All diagnostics are quick and easy to accomplish.

The Launch CRP429 supports full OBD2 testing and diagnostics.
The Launch CRP429 supports full OBD2 testing and diagnostics.

Service Features

Home mechanics will love the service functions of the Launch CRP429. You can reset the oil or brake lights, calibrate the steering angle, and perform DPF regeneration with ease.

And the Launch CRP429 goes beyond the basics, too. It offers limited ECU programming, including injector programming to help lower your emissions. There is also some IMMO and key programming available through the Launch CRP429.


  • Full OBD2 functions and 5 reset functions
  • Fast diagnosis and response
  • Hot keys make navigation quick and easy
  • More affordable option
  • Supports most cars made 2000 and later
  • Wi-Fi connection allows one-click updates


  • Key programming capabilities are limited
  • No ABS bleed functionality

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A video of Launch CRP429

5. Autel Scanner Maxisys MS906 Automotive Diagnostic Scan Tool

Autel’s line of diagnostic scanners is built to exacting professional standards.

 Autel Scanner Maxisys MS906
Autel Scanner Maxisys MS906 Automotive Diagnostic Scan Tool
The Maxisys MS906 is reliable, accurate, and the best bi-directional scan tool for serious DIY mechanics.

Diagnostic Functions

When it comes to diagnostics, the Autel MS906 is one smart scanner. It makes it easy to perform advanced analysis, thanks to the ease of navigating the touch-screen interface. One-touch AutoVIN is just one way the Autel MS906 makes your life easier.

Along with standard code reading, live data, and freeze frame readings, the MaxiSys MS906 lets you perform actuation tests on specific systems. In addition, it supports OBD1 testing for older vehicles.

Repair and coding

The reset functions of the Autel MS906 cover all the major bases. Re-learning TPMS and resetting warning lights for oil, EPB, and SRS systems are just the start of what it can do. The Autel MS906 can also make new keys and program the ECU. Not many bi-directional scan tools in the price range can match its features.

 The Autel MS906 can support all - system diagnostics and program the ECU
The Autel MS906 can support all – system diagnostics and program the ECU.


  • The intuitive display is easy to navigate and use
  • Supports full OBD1 and OBD2 diagnostics
  • Resets all dash warning lights
  • Can re-make keys and reprogram the ECU
  • Supports matching and adaptation
  • Compatible with over 80 manufacturers
  • Automatic system updates through Wi-Fi


  • Price is on the higher side
  • Doesn’t run very long on battery power

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6. Autel MaxiSys MS906BT Bluetooth Automotive Scan Tool

Another excellent choice from Autel is the MaxiSys MS906BT.

 Autel MaxiSys MS906BT
Autel MaxiSys MS906BT Bluetooth Automotive Scan Tool
MaxiSys MS906BT offers professional-level diagnostics and repair capabilities.

Wireless Diagnostics

The Autel MaxiSys MS906BT communicates wirelessly through Bluetooth, letting you perform diagnostics anywhere in your garage. Active bi-directional testing is available for specific systems, allowing you to manually activate solenoids or switches.

Of course, the Autel MS906BT can also perform the basic diagnostics you’ll get from other hand-held scanners. It’s easy to read and clear any code, see pending codes, and run I/M readiness or other sensor tests.

Service Functions

The service functions of the Autel MaxiSyS MS906BT are its most impressive features. In this regard, it exceeds some scanners that cost twice as much, offering reset for 21 common services.

Key programming is another helpful feature of the Autel MS906BT. You can make new fobs, program IMMO systems, and test the anti-theft system. The Autel MS906BT pairs nicely with the advanced ECU coding capabilities for adjusting other electronic systems.

Autel Maxisys MS906BT is an advanced diagnostic scan tool with wireless connection.
Autel Maxisys MS906BT is an advanced diagnostic scan tool with the wireless connection.


  • Features 21 service functions, including TPMS relearn and DPF regeneration
  • Includes key programming functions
  • Capable of advanced ECU programming
  • Active testing for most electronic systems
  • Full OBD2 testing and DTC functionality
  • Bluetooth enabled for remote diagnostics
  • One year of free updates included


  • One of the pricier scanners
  • Active testing not available for all vehicles

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A video of Autel MaxiSys MS906BT.

7. Launch X431 V Pro Bi-Directional Scan Tool

LAUNCH X431 V PRO Bi-Directional Scan Tool
The X431 V is the line’s mid-range offering, striking a nice balance of providing professional features without jacking up the price.

Full system diagnosis

Many scanners provide graphical displays for live and freeze frame data. The Launch X431 V takes this a step further. You can view live data as text or graph from any system, including the transmission, battery, and even climate control and lights.

The active testing support is also impressive on the Launch X431 V. It’s the extent of the bi-directional control we’re impressed by. Adaptation and matching are also no problem for the Launch X431 V. The inclusion of repair resources through the internet also helps home mechanics accurately diagnose the cause of trouble codes.

Reset and coding functions

Reset functions of the Launch X431 V include all dash warning lights, along with TPMS, IMMO, gears, and DPF. The only major thing lacking is key coding—you can match IMMO but not program new fobs. Having said that, it’s one of the most affordable scan tools you’ll find that allows re-programming adaptive ECU data.

Launch X431 V pro can support ECU coding.
Launch X431 V pro can support ECU coding.


  • Includes 15 service functions
  • View all system tests as graph or text
  • Full bi-directional active testing of all systems
  • Supports over 90 brands
  • One-key free Wi-Fi updates for 2 years
  • Built-in option for remote diagnostic and mechanic assistance


  • Limited coding functions
  • Paid subscription required for an update after 2 years

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8. Launch X431 V+ Actuation Test Diagnostic Scan Tool

For the ultimate in automotive diagnostic and repair functions, the Launch X431 V+ is a feature-rich bi-directional scanner.

LAUNCH X431 V+ Actuation Test Diagnostic Scan Tool
While it’s priced out of the budget of most home users, the Launch X431 V+ would make a great addition to a professional garage.

Active testing and diagnostics

The Launch X431 V+ can run any diagnostic test you can think of. Along with requesting information and test results, it can activate specific solenoids or actuators to conduct tests. It can also read or erase codes from any system, not only those connected to OBD2. This includes data on the powertrain, engine, and chassis of your vehicle.

Maybe the best part of the Launch X431 V+ for mechanics is its wide diagnostic compatibility. With support for almost 100 brands and over 10,000 vehicle models, you can test any car on the road. The Launch 431 V+ even supports heavy truck diagnostics.

Launch X431 V+ can support over 80 vehicles.
Launch X431 V+ can support over 80 vehicles.

Programming and coding

To start with, the Launch X431 V+ can perform repairs on any system, including TPMS, transmission, and fuel repairs. You’ll also gain access to advanced coding functions. You can code and customize your ECU, and even program the IMMO system for new keys. In the right hands, the Launch X431 V+ is one of the most powerful bi-directional scan tools on the market.


  • Full system diagnostics with bi-directional testing
  • Includes 11 reset functions
  • Allows coding of the ECU
  • Supports over 93 manufacturers
  • Wi-Fi enabled for one-click updates without a computer
  • Module for diagnosing heavy trucks available
  • Communicates wirelessly via Bluetooth or Wi-Fi


  • Most expensive option
  • Some repair modules and upgrades require payment

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A video of Launch X431 V+

9. Autel MaxiPro MP808 OBD2 Diagnostic Scanner

Another option in the Autel line is the MaxiPro MP808.

  Autel MaxiPRO MP808
Autel MaxiPRO MP808 OBD2 Diagnostic Scanner
MaxiPro MP808’s the best bi-directional scan tool in the mid-range price point for both home mechanics and professional garages.

Active Testing

The advantage of a bi-directional scan tool like the Autel MP808 is manual control of injectors, solenoids, and switches. These active tests are easy to perform with the MP808. You’ll also get easy access to leak down tests, power balance tests, and other advanced diagnostics.

You’ll also love the quick read function, which pulls up every code from your drivetrain and chassis. This is a nice time saver for professional mechanics, especially. Clicking on a code takes you directly to the appropriate module for further testing.

Adaptive Learning

You’d expect programming and learning functions from a pricier scanner, but at this mid-range price point, the Autel MP808 has impressive functionality. Reset functions are just the tip of the iceberg. The Autel MP808 also programs keys and lets you re-learn ECU coding for most electronic systems.

Autel MP808 provides you with 18 special features.


  • Quick read function makes diagnostics easier
  • Capable of programming keys
  • Adaptive learning and calibration of most systems
  • Supports all major system resets
  • Compatible with over 80 manufacturers
  • User-friendly interface with the option to connect to the computer


  • Programming functions more limited than costlier options
  • Subscription renewal does require payment

Check Price at Amazon

The Final Thoughts

The best bi-directional scan tool in our opinion is Launch X431 Diagun IV. It provides professional-level features for a very affordable price. In addition, it’s compatible with a huge array of vehicles, so there’s no worrying about compatibility.

No matter which of these scanners you get, though, it’ll open up a whole new world of possibilities. A bi-directional scan tool is truly an investment that will easily pay for itself in saved trips to the garage. We hope we’ve helped you find the right one for your car!

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