A bi-directional scan tool can do things that ordinary scanners can only dream of. Imagine this: you get into your car and prepare to drive. Since it’s a beautiful day, you try to roll down your window to enjoy the breeze. But then you realize that the driver window can’t roll down. It has failed on you out of the blue. So, you test the other windows and discover that they are working just fine.
How do you test and diagnose that driver window without necessarily checking the other windows?
By using a bidirectional scanner. It will allow you to bypass the electronic control module on the driver’s window and directly communicate with the car’s engine control unit (ECU). Therefore, you can attempt to roll the window up and down using nothing but the scanner. And if it works, then you’ll know that the window regulator on the driver’s side is not the issue. Easy stuff if you have a bi-directional scan tool. Yet it’s an impossible task if you are using an ordinary scanner.
Best Bi-directional Scan Tools – Editor’s Picks
|Editor's Picks||Product Model||Our Rating|
|Best Overall||LAUNCH X431 V PRO||9.5/10|
|Runner Up||LAUNCH X431 PROS Mini||9.5/10|
|Best Budget Buy||FOXWELL NT630 Plus||8.5/10|
|Best Value||Autel MaxiCheck Pro||8.5/10|
|Also Great||Autel Maxidas MP808||7.5/10|
Table of Contents
- 1 Best Bi-directional Scan Tools – Editor’s Picks
- 2 What Is A Bi-Directional Scan Tool?
- 3 Buying Guide: How to Choose the Best Bi-Directional Scan Tool
- 4 Best Bidirectional Scan Tools Review
- 5 Conclusion
- 6 How to Use A Bi-Directional Scan Tool?
What Is A Bi-Directional Scan Tool?
A bidirectional scanner is a device that can send and receive information to and from a vehicle’s onboard computer. In other words, it can request information from a vehicle’s computer or send commands to the vehicle’s modules. Those commands will make the module to perform specific tests and functions. Ordinary scanners can only receive info from a car’s computer, but they can’t send orders.
Just in case you didn’t know, an OBD scan tool is a device that pulls diagnostic data from a vehicle. OBD is short for onboard diagnostics. And it explains how cars work. Every vehicle has an onboard computer that checks to ensure that its mechanical and electrical systems are working correctly. When a system fails, the car’s computer detects that failure. It then records the issue in its built-in memory as a diagnostic trouble code (DTC or “code”). When you view that code, you’ll know two things.
First, you’ll know which system malfunctioned. It could be the engine, transmission, ABS, airbag, body component, etc. Secondly, you’ll see whether it’s a mechanical problem (a module, sensor, or similar component failed) or an electrical problem (open circuit, short circuit, power not reaching a module, etc.)
The thing is, you can only view those codes if you plug an OBD scan tool to the car. The scanner initiates a request from the vehicle’s computer. The latter responds by sending the diagnostic data (recorded codes) to the scan tool. From there, you can view the DTCs on the scanner and figure out precisely what the issue is. At least that’s what you can do with an ordinary scanner, i.e., view diagnostic codes. On the other hand, a bidirectional diagnostic tool can display codes and send commands to the car. Hence the “bidirectional” property of it. For example, you can activate and pressurize the fuel pump by merely sending a command from the scanner to the car’s computer. Similarly, you can use it to receive fuel pump codes like Error Code P0230. Thus, it will have sent a command and received information from the ECU.
Sending commands is also known as an “active test”, actuator test, system test, or inspection test. It is necessary when you want to activate and control an onboard system remotely.
Recommendation – LAUNCH X431 V PRO – Top rated bi-directional scan tool 2020Check Price at Amazon
Buying Guide: How to Choose the Best Bi-Directional Scan Tool
If you’re looking to get your hands on an automotive diagnostic scanner with bidirectional control abilities, here are the things to keep in mind:
The Brand Matters
Strong brands offer peace of mind. And as far as diagnostic scanners, it’s always wise to buy your scan tools from the best brands out there. They not only deliver a positive experience consistently, but they also provide frequent software updates. That’s important because you want a scanner that will be compatible with current and future vehicles.
Besides, most of the big players offer the best customer support. If your scanner (and at times vehicle) fails, you can give them a call, and they will help. With that in mind, which OBD brands have the best products?
Founded in 1992, Launch Tech Co Ltd is the biggest manufacturer of automotive diagnostic tools. The company has sold over 1 million units of scanners, including a good number of bidirectional models. It operates worldwide with distribution centers in the U.S., U.K., Australia, Japan, Mexico, South Africa, Germany, Russia, and other countries.
Like Autel, Launch takes pride in R&D. However, it has a broader range of products that include diagnostic tools, auto testing, and auto cleaning equipment. While most Launch scanners are entry-level, some models are high-tech and suitable for mechanics and experienced DIYers.
Recommendation – LAUNCH X431 V PRO
If Autel’s 10% investment in R & D is impressive, you’ll be blown away by Foxwell’s 20%. The scan tool maker’s mission is to “innovate, change and lead the automotive diagnostic industry.”
And indeed, they do. Foxwell scanners are smart yet simple enough to be used by professional mechanics and DIYers alike. The company focuses strictly on automotive diagnostic tools like bi-directional scanners and electrical brake tools.
That level of specialization means that they understand their industry inside out, so you can never go wrong with a Foxwell scan tool.
Recommended products – FOXWELL NT630 Plus
Autel’s biggest strength as a brand is research and development (R&D). The company invests just over 10% of its revenue in product development. For that reason, every new Autel product is always better than the previous one. The scanners improve based on changes in automotive technology.
It’s a good thing that Autel has operations in the U.S., Germany, U.K., Australia, and a few other countries. The vast network enables them to track auto tech in real-time.
One good thing about Autel is that they offer aftersales support for their old and new scanners. Most other brands usually abandon customer support when a scan tool is 2 or 3 years old. Not Autel. You can rest assured that even if you buy their 2010 products, it will come with customer support.
Recommendation – Autel Maxisys MS906BT
Innova is one of the oldest manufacturers of aftermarket car diagnostic tools. It was established in 1990 by Equus Products as an R&D wing of the company. Through R&D, Innova became an industry leader in OBD scanners.
In 1996, the company became the first to make it mandatory for all its product development team to have Automotive Service Excellence (ASE) certificates. The move paid off because today, there are well over 30 highly-trained ASE+ Master Techs at Innova.
They focus on bringing brilliant automotive diagnostic ideas into life through OBD scanners. For example, Innova has its own OBD database, allowing users to access repair tips and procedures quickly.
Recommendation – INNOVA CarScan Pro 5610Check Price at Amazon
A bidirectional scan tool has professional and DIY-level features. Below is a list of the critical functions to look for:
Actuator Tests (“Active Tests”)
This process involves the scanner sending commands to solenoids, switches, and relays. Those commands ask a module or sensor to perform specific tasks. One good example is using a scanner to turn the fuel pump on or off.
But please note that not all scan tools in this review can perform active tests on all systems. For example, Foxwell NT630 Plus can only run actuation tests on the ABS and airbag system; Autel Maxicheck Pro can support component tests on all detectable modules.Check Price at Amazon
Often used synonymously with matching and relearning, adaptation is the process of making a new, replacement part compatible with the vehicle’s existing ECU. Usually, when you replace a component like transmission, brake, or TPMS, the ECU needs to communicate. For that to be possible, you have to create a sort of “communication channel” using a bi-directional scanner.
Recommended product – Autel Maxidas MP808Check Price at Amazon
Coding and Programming
Coding and programming involve changing a vehicle’s settings (parameters) through deep access to the engine control unit. You can tune, remap, code, or program a module to perform differently from its specifications. For example, you can modify the throttle stop by coding the injector. Simultaneously, coding and programming provide an in-depth look into vehicle systems, thus helping mechanics troubleshoot and deal with complex vehicle problems like drivability issues, fuel inefficiency, power loss, the durability of parts, fault codes.
Recommendation – Launch X431 V+
Full OBD2 Diagnostic Functions
Any bi-directional scan tool can offer all the OBD2 functions, such as:
- Retrieve a car’s VIN, read DTCs,
- Provide live sensor data,
- Locate bad O2 sensors,
- Give access to emissions readiness status,
- Run EVAP system test,
- Turn off the Check Engine Light (CEL) or malfunction indicator lamp (MIL),
- Reset monitors,
- EVAP test,
- Read live data, etc.
Recommended product – Foxwell NT630 PlusCheck Price at Amazon
Full System Diagnosis
An added feature of bidirectional scanners is that they enable you to control onboard systems. The scanner can tell you what is wrong with the Engine, Body, Powertrain, Chassis. They include the ECM, ABS, SRS, transmission, BMS, EPB, SAS, TPMS, wiper system, fuel system, etc. You can pull ECU information, read and clear codes, and view live data. In doing so, the scanner helps you to detect issues and perform major maintenance and repair tasks.Check Price at Amazon
Finally, a half-decent bidirectional scan tool can perform a ton of service functions. For example, it can reset oil service, reset EPB, perform battery service, bleed brakes, regenerate the DPF, do IMMO keys, calibrate the SAS, etc.
Recommendation – LAUNCH X431 DIAGUN VCheck Price at Amazon
You’ll generally find bidirectional scanners in all price ranges starting from $100 to $1,200 or more. Here’s a better breakdown and what to expect in each price tier:
Under $500: these will typically offer actuation tests and full OBD functions. The biggest concern with these scanners is that they mostly don’t give you access to all available systems. For example, you may find that you can diagnose the engine, transmission, ABS, and SRS but not the SAS, EPB, or any other systems.
Recommended product – FOXWELL NT630 Plus
$500+: a bidirectional scanner in this price range will often do actuator tests, adaptation, coding, and programming. However, most of them are only compatible with OBD2 vehicles, not OBD1.
Recommended product – LAUNCH X431 V PRO
1,000+: in addition to actuator tests, adaptation, coding, and programming, high-end bi-directional scan tools offer fancy features. For example, most of them come with a browser that you can use to troubleshoot diagnostic issues online. Plus, they support wireless connectivity, which allows for high mobility as you work.
Recommended product – LAUNCH X431 V+Check Price at Amazon
One underrated feature of high-end scanners is that they run on Android OS. It is faster when refreshing live data and can graph multiple PIDs effortlessly.
A car is either OBD1 or OBD2. OBD1 vehicles are those that were manufactured in 1995 or earlier years. OBD2 ones, on the other hand, are 1996 or newer models. Bidirectional scanners are created with those two systems in mind.
While some are designed strictly for OBD2, others are compatible with both OBD1 and OBD2. Of course, if you are a mechanic or enthusiast who works on many different cars, you’ll want a compatible device with OBD1 and OBD2.
On the other hand, if you are just an ordinary car owner, you’ll most likely be happy with a scanner that’s only compatible with your vehicles. If they are all OBD2 vehicles, it won’t hurt going for an OBD2 bidirectional scan tool.
Best Bidirectional Scan Tools Review
1. LAUNCH X431 V PRO
Launch’s X431 V PRO is an improved version of the X431 V. This latest model comes with an 8-inch screen and Android 7.1 OS.
As far as vehicle coverage, you can use the X431 V PRO on all mainstream car brands; domestic and foreign. It supports both OBD1 and OBD2 diagnostics.
However, the range of OBD1 cars that it supports varies from one make to another. For example, it can only go as far back as 1991 for Chevy, 1990 for Toyota, and 1988 for Ford.
Nonetheless, Launch does throw several OBD1 cables in the package in addition to the OBD2 wireless dongle. That’s great if you are a mechanic who always works on a variety of OBD1 and OBD2 vehicles.
Here’s what you can do with this bi-directional scan tool:
The Launch X431 V PRO can perform actuator tests in all the mainstream car brands, including Benz, Audi, Ford, BMW, GM, Ford, Toyota, etc.
An actuation test is where you use the tool to tell the PCM to command an actuator to perform a function. For example, you can activate fuel injection, turn on headlights, roll down a window, etc. using the scanner. This function is also called Mode 8 or “active test”. It’s necessary when you want to see whether an actuator or sensor is working as it should.
So, which systems can you perform these “active tests” on? The scan tool covers all available systems such as the TCM, ECM, ABS, SAS, TPMS, BMS, etc.
Coding or programming is the process of changing a system’s parameters. For example, ECU coding involves changing a ROM file in the engine control unit.
Programming is necessary when you want to modify a vehicle’s system beyond the manufacturer’s specifications. A good example is turbocharging or supercharging an engine.
Both of those require you to program the ECU. Similarly, if you want to upgrade fuel injection, you have to do fuel injector coding and modify the throttle stop.
The same goes for gear shift mapping, throttle fuel volume mapping, and many others. If you have the Launch X431 V PRO, you can program or code all these systems. They include the ECU, fuel injector, gear shift, throttle fuel volume, etc.
Better yet, it supports online coding for some car models like VW, Audi, Benz, BMW, and Porsche. You, however, must ensure that you buy the international version of the scanner. Otherwise, it won’t be compatible with most American and European vehicles. Also, update it as soon as it’s delivered. The new software upgrade will unlock coding/programming for a wide range of cars.
Another handy feature of this bidirectional scanner is that it supports adaptation, making a replacement part compatible with the ECU. For example, if you replace the throttle body, the electronic throttle control (ETC) will not automatically recognize the new throttle body. You, therefore, have to adapt/relearn/match it to make it recognizable. The Launch X431 V PRO does that for all systems. You can use it to relearn the TPMS, throttle body, transmission, etc. It can even do key-matching.
Vehicle Health Report
The X431 V PRO is not just an automotive diagnostic scanner with bidirectional control abilities. It does offer some of the primary and special diagnostic functions as well. For starters, you can use it to pull and erase trouble codes in all systems. It also displays and graphs live sensor data from all available systems.
The only issue is that the scanner’s refresh rate is relatively low, especially when you graph four or more PIDs.
To top it all off, you get well over 30 reset functions with the X431 V PRO. That includes oil reset, DPF reset, ABS bleeding, cluster reset, and many more. You can save all the codes, live data, and every other diagnostic data in the built-in 32GB storage. Furthermore, Launch ship this particular unit with a printer for printing out DTCs for customers who may be interested.
Overall, the Launch X431 V PRO is a reliable bidirectional diagnostic tool. It’s arguably the best on the market today. Nonetheless, keep in mind that a Chinese-based company supports it. And while their customer support is excellent, reaching them is an uphill climb.Check Price at Amazon
2. LAUNCH X431 PROS Mini
The Launch X431 Pros Mini is a replica of the X431 V PRO above as far as functionality. So, what makes the Pros Mini a cheaper bidirectional diagnostic tool?
For one, it’s shaped like a smartphone while the V Pro looks like a tablet. Secondly, the Pros Mini comes with Android 5.1 compared to the V PRO’s 7.1. And that’s one issue with this particular scanner. Launch advertises that it comes with Android 7.0 when they equip it with Android 5.1. Finally, instead of 32GB of storage that you get with the V PRO, the PROS Mini offers a modest 16GB.
Are those enough reasons to ditch the Launch X431 Pros Mini for the Launch X431 V PRO? Hardly. You’ll get the same functions if you choose this one, but for a slightly lower price.
This bidirectional diagnostic tool works on OBD1 and OBD2 vehicles. It connects to OBD2 using Bluetooth. The good people at Launch ship 12 OBD1 adapters for various car makes. They include GM, Chrysler, Nissan, Mitsubishi, Toyota, BMW, and Hyundai.
Again, the major downside is that you can only go so far back in OBD1 diagnostics. The scanner won’t work in 1990 or older Chevys, 1989 or older Toyotas and 1987 or older Fords. Nonetheless, you can perform a wide range of bidirectional functions if the car is compatible.
As a bidirectional scanner, the Launch X431 Pros Mini supports actuation tests on all mainstream vehicles. You can do such simple tasks as expressing a window to more complex ones like activating fuel injection. In all, the device can perform “active tests” on all available systems. They include the ABS, SAS, TCM, ECM, etc..
Adaptation and Coding
Alongside actuation tests, you can use the Launch X431 Pros Mini for matching or relearning new replacement parts. That’s a handy function if you are a professional or shade-tree mechanic who frequently replaces sensors, actuators, etc. Additionally, this bi-directional scan tool can do coding and programming. Whether you want to do ECU coding, injector coding, or simply program a module like a gear shift, you can do it all with the X431 Pros Mini.
Like all other high-end scanners, this bidirectional diagnostic tool can read and clear codes, pull and graph live sensor data, scan all the available systems for faults, perform reset functions like DPF regeneration, and save/print diagnostic data.
Launch X431 PROS Mini is an excellent automotive diagnostic scanner with “active tests”, especially if you want a professional-level device. It also makes a perfect alternative for the more expensive Launch X431 V PRO.Check Price at Amazon
3. FOXWELL NT630 Plus
With a price tag of under $140, the Foxwell NT630 Plus is a steal. There’s a tradeoff, though. You can only do bidirectional controls in the ABS and SRS modules.
So, what exactly can you do? Well, this affordable bidirectional scanner allows you to run actuation tests on the ABS and SRS. That means you can activate and deactivate ABS and airbag sensors, switches, and relays. More specifically, you can do ABS manual control tests, motor tests, version tests, actuator tests, and auto-bleed tests.
The downside is that it doesn’t support bidirectional functions in any other systems apart from ABS and airbag systems.
The Foxwell NT630 Plus can help you install new brake components. It doesn’t do relearning, but it does ABS bleeding (removing air from brake components (calipers, cylinders, lines, hoses, etc.) after replacing them). So, while you can’t use it to relearn new parts, it may come in handy when you need to bleed out air.
Although you won’t get many bidirectional controls with the NT630 Plus, you’ll have all the necessary OBD2 functions. The scanner supports reading and clearing of codes in the engine, airbag, ABS, and SAS. It also pulls VIN automatically and can save/print diagnostic data.
Although Foxwell NT630 Plus is not a high-end unit, the scan tool holds its own when it comes to ABS and airbag bidirectional controls. It is an ideal pick if you’re looking for something more affordable than fancy.Check Price at Amazon
4. Autel MaxiCheck Pro
The Autel MaxiCheck Pro is a well-balanced bi-directional scan tool. It offers a decent number of OBD2 functions in addition to bidirectional tests. It’s correctly priced, too. You’ll love it if you are a DIY mechanic or enthusiast.
The most significant selling point for the MaxiCheck Pro as a bidirectional scanner is to do component tests. This process simply involves activating and actuating a component to see if it’s working as it should. For example, if your parking brake is acting up, you can apply and release it using the scanner. That will tell you whether the issue is with the brake module or its circuit.
Now, this scan tool supports component tests on all detectable modules. That’s excellent. The only problem is that it’s the only bidirectional function that you’ll get.
Although the MaxiCheck Pro offers a limited range of bi-directional functions, it has other features. It can read and clear codes in the SRS, SAS, EPB, BMS, and other systems. That’s on top of live and freeze frame data. The scanner offers a decent number of service functions. For example, you can bleed the ABS, reset oil, and do battery maintenance.
As an OBD2 bidirectional diagnostic tool, the MaxiCheck Pro is designed for 1996 to 2015 vehicles. There’s every possibility that it won’t work on a 2016 or newer vehicle. Therefore, to be on the safe side, give Autel a call first to ask whether the scanner is compatible with your car.
The MaxiCheck Pro is another bidirectional scanner that shuns fancy features. It’s great if you want the right mix of OBD2 functions and component testing.Check Price at Amazon
5. Autel Maxidas MP808
The Autel Maxidas MP808 is a tablet-like bidirectional diagnostic tool that runs on Android. It’s a lot more powerful and offers more features than the MaxiCheck Pro. On the downside, the software update process is not a walk in the park. Nonetheless, it brings a ton of bidirectional controls to the table for professionals and enthusiasts.
First of all, the Maxidas MP808 can activate and actuate all available modules. Whether you want to do fuel injection, wiper activation, or any other component test in-between, you can use the scanner.
The Autel Maxidas MP808 gives you the option to perform adaptation and relearning of different components, including the shift, TPMS, crankshaft position, MAF sensor, transmission, etc. You need this function when modifying or replacing parts. It’s even more critical if you are a professional mechanic.
Just as crucial to mechanics is coding. And you’ll be glad to know that this OBD2 scanner with “active tests” supports both injector coding and ECU coding. You can do key coding as well.
In addition to all the above, the Maxidas MP808 can work as an all-system code reader. It can display PIDs even though the graphs are not that detailed. But the one place where this bidirectional scanner comes into life is reset functions. You can reset oil, EPB, ABS, TPMS, DPF, SAS, SRS, and other systems.
Autel’s Maxidas MP808 errs more on the high-end side than the entry or mid-level range. It packs features that any mechanic or experienced enthusiast would love in a bi-directional scan tool.Check Price at Amazon
6. LAUNCH X431 V+
If you need something better than the Launch X431 V PRO (check #1 above), you’ll love the Launch X431 V+. While they both run on Android, Launch equips the latter with Android 9.0. The more powerful OS brings the benefit of a better set of features, albeit slower. It’s also more expensive, as you would expect. Still, here’s what you’ll be paying for:
This is where the Launch X431 V+ blows most other bidirectional scanners out of the water. It supports OE-level coding and programming for some of the most popular car brands like Benz, VW, BMW, GM, Ford, etc.
That means you can use the scanner to change manufacturer-specific settings in a compatible vehicle. These are usually settings that only manufacturer scan tools can reach, not aftermarket tools the X431 V+. To be more specific, you can use it to code and program manufacturer parameters in the ECU and injector. It also supports key coding.
Just like its predecessor (Launch X431 V PRO), the X431 V+ can do online coding, which means that you can code some modules in a car that’s far away THROUGH THE INTERNET.
However, the car must be registered to your scanner, and you must first log into Launch’s online account. It’s a pretty secure system, and once you register a car, you can code its components remotely. Let’s say, for example, that a loved one lives a few miles from you. Instead of going over there every time you need to code some components in their car, you can simply do it from your home’s comfort over the internet.
Adaptation and Relearning
As you would expect from a scanner of this price range, the X431 V+ can adapt, relearn, and match new components. It covers all the available systems, from the transmission and brake to the power steering and TPMS and everything in-between. You can, therefore, use it to replace parts on any compatible vehicle. Simply relearn the new component to make it compatible with the ECU, and it will start working immediately.
This bidirectional diagnostic tool works as an ordinary scanner. It can read/clear codes on available systems. Thus, you can scan the ECM, ABS, SRS, transmission, BMS, EPB, SAS, TPMS, chassis components, etc.
Additionally, the Launch X431 V+ performs service functions and resets modules. Alongside DPF regeneration, it can reset the oil light, reset EPB, perform battery service, bleed brakes, do IMMO keys, calibrate the SAS, etc.
As far as other data, you can use this scanner to pull live and freeze frame data, view vehicle information, and save/print diagnostic results. Yes, it can graph live data as well. One bummer is that it can’t graph more than 4 PIDs at a time. And it can get slow at times, like really slow when refreshing data.
Ignoring the negligible drawbacks, the Launch X431 V+ is a great, modern-day professional scanner. It has all the bells and whistles for pro-level diagnostics, including a browser and internet connectivity for research and online coding.Check Price at Amazon
7. LAUNCH X431 DIAGUN V
Launch’s X431 DIAGUN V represents the ultimate bang for the buck. In addition to bidirectional controls, the scanner offers loads of diagnostic functions. It barely has a negative feature.
First off, the X431 DIAGUN V activates solenoids and actuators for “active testing”. Secondly, it performs component tests. The scanner is, therefore, fully equipped for all forms of actuation tests.
Adaptation and Matching
As an automotive diagnostic scanner with bidirectional control abilities, the Launch X431 DIAGUN V can relearn and match modules. Whether you’re replacing the TPMS, transmission, battery, or what have you, you can relearn the new component with the ECU.
Speaking of the ECU, this bidirectional scanner does support ECU coding and programming. Additionally, it can do injector coding and key coding.
Full System Diagnosis
The icing on the cake? This scanner diagnoses every available system in a vehicle. It brings more than 20 reset functions to the table as well. They include ABS bleeding, SAS reset, oil reset, brake reset, etc.
For the price, it’s tough to beat the X431 DIAGUN V. It does have a pricing downside, though. Software updates cost $399 per year.Check Price at Amazon
8. Autel Maxisys MS906BT
The Maxisys MS906BT is a high-end model designed with professional mechanics in mind. It comes at a steep price, but of course, with exceptional features. If, for example, you are looking for mobility while running diagnostics, you’ll love that the scanner allows for wireless connectivity over a 164-foot (50-meter) range. That’s arguably the least of the fancy features. Below come the main ones:
This is a given considering the price. It’s an important point to mention nonetheless because the Autel Maxisys MS906BT supports bi-directional control on all available systems. You can activate/deactivate a solenoid, switch, or relay to determine whether it’s working.
Like the Launch X431 V+ above (check #6), the Maxisys MS906BT can code on the original equipment installed by a vehicle’s manufacturer. However, it doesn’t work on every single car make and model. Therefore, start by sending the good folks at Autel an email asking whether you can do EO-level coding in your car. Another issue with this scanner is that it can’t perform ECU programming. At its price, that’s honestly a bit of a bummer.
Yes, the Maxisys MS906BT can help you replace parts in a vehicle. It can do component relearning and matching.
The list of what you can do with this bi-directional scan tool is endless. You can diagnose all available systems, view live data in text or PIDs, calibrate the SAS, reset oil, regenerate DPF, register battery, reset brake pads, etc.
The Autel Maxisys MS906BT is designed and priced for professional mechanics. So, if you run an auto shop, you may want to check it out.Check Price at Amazon
9. FOXWELL NT624 Elite
In typical Foxwell style, the NT624 Elite is a lowly-priced bi-directional scan tool. But as you would expect, the affordable price tag comes at the cost of some functions. Below is a lowdown of what it can and can’t do:
The only bidirectional part on the Foxwell NT624 Elite is “active tests“. You can activate and test the EPB, power steering, ABS-DSC, integrated chassis management system, and the A/C system. There are no more bidirectional functions beyond that. Foxwell states that the “NT624Elite scan tool cannot perform coding & programming or other bi-directional test functions.”
Regardless, the NT624 Elite is a beast when it comes to OBD2 functions. The scanner takes a rather interesting approach in that it doesn’t diagnose the four main systems (engine, ABS, SRS, and transmission). Instead, it focuses on the HVAC, BCM, instrument cluster, TPS, TPMS, DPF, and other systems.
Special and other Functions
Alongside OBD2 functions, the NT624 Elite supports EPB service and oil reset. It can display codes as well as live sensor data.
If you don’t have the budget for pricier bi-directional scan tools, you can consider going for the Foxwell NT624 Elite. It’s a mid-range scanner with just-enough features for ordinary car owners.Check Price at Amazon
10. INNOVA CarScan Pro 5610
Another bi-directional scanner that won’t cost you an arm and a leg, the INNOVA CarScan Pro 5610, is mainly suitable for “active tests”. It also supports other diagnostic functions that car owners and enthusiasts may cherish.
This is the only bidirectional function on the CarScan Pro 5610. It allows you to test solenoids, switches, and relays in available systems. By doing so, you can tell whether a problematic sensor/module is faulty due to mechanical or electrical issues.
Top on the list of additional functions that the Innova 5610 has is code reading/clearing and live data display. Besides, it lets you check emission status, reset the EPB, bleed the ABS, and perform battery service.
Perhaps surprisingly, the CarScan Pro 5610 is compatible with both OBD1 and OBD2 vehicles. OBD1 is optional, and if you want to take that option, you will have to buy an OBD1 adapter separately.
The Innova CarScan Pro 5610 is pretty decent as long as you’re not looking to do any coding and programming. It’s essentially a bidirectional scan tool for “active tests” only.Check Price at Amazon
As you may have noticed, bi-directional scan tools are essential in diagnosing, repair, and maintaining vehicles. But if you want to get the best out of one, it must be an excellent scanner to start with. Any of the ten options above will do a more-than-decent job. Just make sure that the one you go for has all the features that you need.
How to Use A Bi-Directional Scan Tool?
An automotive diagnostic scanner with bidirectional control abilities can send and receive information from the vehicle’s control modules. It, therefore, needs to connect with the car first.
To do that, start by connecting your bi-directional scan tool to the car’s onboard computer. There are two ways of doing that.
Simply hook that cable to your car’s OBD2 port. You can find that port inside the driver’s compartment, usually below the steering wheel. It’s easy to identify because it has 16 pins. Power up the scanner, and you’ll be good to go.
The second method of connecting an OBD scanner to your car is wireless, which applies to bi-directional scan tools that either use Wi-Fi or Bluetooth to connect to the car’s ECU.
Some examples include the LAUNCH X431 V PRO and LAUNCH X431 PROS Mini, both of which use Bluetooth. They come with a small dongle for transmitting wireless signals. Plug that dongle into your car’s OBD2 port. Now power up the scanner, head over to its settings, and pair it with the dongle via Bluetooth. That’s it!
But how do you use a bidirectional scanner for diagnosis? Here’s a step-by-step guide. We will assume that you want to test the driver window. However, the process applies to any other bidirectional test.
Step 1: connect the bi-directional scan tool with your car’s OBD computer. Power up the scanner.
NOTE: Steps 2 to 9 provide a general procedure. The exact process may vary slightly from one scanner to another.
Step 2: On the scanner, choose the type of diagnostics that you want to run. That would be “Traditional Diagnose” for bi-directional functions.
Step 3: Enter the make and model of your vehicle. The scanner will then automatically identify the car and display the VIN, engine type, year of manufacture, etc.
Step 4: You’ll then get a menu asking you to choose between a health report, system scan, and system selection.
Choose “system selection.”
Step 5: The scanner will pull all the available systems and display them. Choose the system that you want to actuate.
For example, if you want to test the steering wheel, you will select the “Power Steering Control Module (PSCM).” In our case, we are trying to test the driver window. Therefore, we will choose the “Body Control Module (BCM).”
Step 6: The next menu will contain all the functions that you can do to the selected system. You can simply view its information. You can read and clear its trouble codes. There’s even the option to pull live data streams or perform special functions.
But since we are interested in an actuation test, that’s what we should select.
Step 7: Select the car component that you want to run bidirectional tests on. Each module has several parts. For example, the BCM has chassis, power management, lighting, keyless entry, wipers, and windows, just to name a few.
We are interested in windows. Therefore, that’s what we will select.
Step 8: Choose the window regulator that you want to actuate.
In this example, that would be the driver window motor. When you tap on it, the scan tool will display a notification telling you what to expect. I.e., if you express the window up, it will roll-up. Conversely, if you express it down, it will roll down.
Step 9: Tap “OK” and proceed to the next menu. It will allow you to choose specific commands.
Now, if you want to roll the window up, tap “Express-Up“. “Express-Down” does the opposite while “Up” rolls the window one step upward.
With that, you will have performed an actuation test on the driver’s window. If the window rolls up/down, you can tell that the regulator is working just fine. Proceed to diagnose the circuit and other components.
It’s the same with other systems. For example, if you’re dealing with a no-start situation, you can use an automotive diagnostic scanner with bidirectional control abilities to turn on the fuel pump. If the fuel pressure gauge indicates sufficient fuel pressure, you can rule out the fuel pump and fuel pump circuit failure. Proceed to check whether the fuel input sensor is working correctly and enough oil in the car.
Those are just a few examples. There are tons of actuation tests that you can run with a bidirectional diagnostic tool. You can turn the steering wheel, cycle the A/C on and off, perform an EVAP system leak test, etc. But of course, you need the best bi-directional scan tool to get the job done.