Over the past several decades, computer chips and control electronics have become as essential to motor vehicles’ efficient, reliable operation as any mechanicals. An ever-growing list of a car’s mechanical systems — be it the engine and transmission, brakes, suspension, emission controls, , accessories and even the — is managed by an increasingly complex network of electronic controls and electrical sensors.
That’s where onboard diagnostics come in, and why an OBD2 scanner has become a key tool to understand, maintain and repair modern vehicles. Do-it-yourself types, or anyone who wants to stay on top of what’s going on inside their vehicle, can put an OBD2 code reader to good use. An OBD2 reader can certainly be useful for saving a few bucks.
It’s equally clear that choosing an OBD2 diagnostic scan tool can be intimidating, and that’s why we’ve assembled this list. There are hundreds if not a thousand scanners out there in auto parts stores, discount stores and at the far fringes of the internet, withby literally thousands of dollars. Many are excellent, regardless of price. Many are junk, with nothing like legitimate product support. Our best list includes the right OBD2 scanner tool for every purpose and buyer, and we’ll update it periodically. Stay tuned afterwards for an overview of how scanners work, what they can do, our methodology for choosing them, key things to consider before purchasing and some pro tips.
The CarScan Pro delivers pro-grade functionality at a consumer price. This dedicated OBD2 scan tool works on nearly all German, Japanese and American-made cars built for North America after 1996. It can decipher virtually every diagnostic trouble code, or DTC, that a car can generate. It can scan virtually every individual control module in the car, including more recent developments like tire-pressure monitors in newer vehicles, and not just basic universal systems like the engine and emissions controls. It can run a simulated smog test, evaluate the battery and alternator and show live data for engine operation, anti-lock braking and other systems during a road test. It ranks faults based on importance and shows “Freeze Frame” data, or a snapshot of exactly what was going on in the car when its control electronics triggered the trouble code to begin with. This car diagnostic tool can even predict a DTC that’s likely to flash in the near future.
Yet what separates the CarScan Pro diagnostic scanner from most OBD2 scan tools is bidirectional control — a feature sometimes called active testing. The CarScan Pro allows you to send commands to your vehicle to test the functionality of a given system, just like a tech at a dealership. It can make adjustments the car manufacturer allows in its control software — say small changes in idle speed — and disable certain modules in advance of mechanical repairs. Car enthusiasts fond of the early 1990s will appreciate one more CarScan Pro feature: With the right connection adapter, it can also scan OBD1 diagnostics in many cars built before 1996.
This car scanner has a large, crisp, color screen, an intuitive user interface, quick-read LEDs that help classify issues fast and hot keys that minimize the number of menus and selections required to get where you want to go. It’s fully self-contained in a high-impact plastic case, with a thorough manual and full-time, US-based phone and web support, but it also allows Wi-Fi or Bluetooth connection to both Apple and Android smartphones. With Innova’s RepairSolutions2 app, the connection opens this car code reader to a range of data on the internet, including repair tutorials, maintenance recommendations and direct links to finding parts.
All told, the Innova Car Scan Pro OBD2 tool offers outstanding features on a solid foundation of functionality and support. It’s everything a car hobbyist is likely to need at a price thousands of dollars below professional, dealership-style OBD2 scan tools.
BlueDriver connects to a car’s OBD2 port, and then to a smartphone control app via Bluetooth. It offers nearly all the features available in higher-end dedicated devices for the price of a basic dedicated OBD2 corded scanner.
BlueDriver can read trouble codes, like other so-called Bluetooth dongles, with an easily understood description of the problem as opposed to an alphanumeric designation you have to look up. It can clear codes, of course, and display Freeze Frame data (a snapshot of what was happening in the vehicle when the fault code was triggered). The Bluetooth scanner can run a simulated smog test and show live, operational data from the engine and chassis as the vehicle operates. It can save or print reports describing problems, potential causes and possible fixes.
It’s those possible fixes that separate BlueDriver from the Bluetooth OBD2 scanner pack. This dongle connects to Identifix — a database used by auto repair shops with millions of potential solutions, no subscription required — and ranks the potential problems that triggered the trouble code to begin with. It also ranks possible repairs. We’d guess that’s a better start than Googling potential causes and fixes, in terms of time efficiency and maybe even cost.
The phone app has clean, easy to process graphics, and the package comes with US-based support via phone, email or live chat. Comparing purchase price to features and capability, the BlueDriver Bluetooth Pro OBD2 scanner could be the best value you’ll find.
This OBD scanner beauty comes from the world’s largest auto supplier, and one of the oldest names in automotive electrics and diagnostics. If there’s an OBD2 code reader that works on any given Asian, European or North American vehicle built over the last 25 years, this is it. So if you’re looking for the best OBD scanner for Audi, Chevrolet, Ford, Honda, Lexus, Subaru or Volkswagen vehicles, it’s probably going to be this one.
The ADS 625 is a 10-inch tablet wrapped in a thick rubber case, but that’s only the start of the handheld scanner kit. There’s a separate wireless Vehicle Connection Interface (the size of a small smartphone) that can also interface with a PC, and a docking and charging station. The OBD connection cable has a light and built-in voltmeter, and there’s an AC adapter just in case you forgot to set the ADS 625 back in the docking station.
This code reader allows full bidirectional control, or the maximum manipulation and calibration allowed in a manufacturer’s software controls. It delivers full-color OE wiring diagrams, component and module locations, confirmed fixes, maintenance procedures, service bulletins and Bosch Repair Source — a comprehensive service and repair information library. It has 5-megapixel front and rear cameras to share photos or include them in vehicle scan reports. It also has a vehicle noise, vibration and harshness analyzer and a web browser for full internet access. Last but not least, it comes with a lifetime warranty as long as you maintain a diagnostic subscription.
If the price of this diagnostic tool still seems a bit steep for shade-tree use, you can add it to your wish list.
FIXD is a reasonably priced scan tool for anyone who’s interested in vehicle care and maintenance, with a twist. This compact wireless OBD2 scanner dongle is designed to stay in a vehicle’s OBD2 port all the time, and it sends push notifications to its corresponding app on an Apple or Android smartphone. It helps DIY beginners better understand proper vehicle care, and it provides useful comparison information.
FIXD will actively scan a vehicle’s diagnostic system at your request, report trouble codes in plain English and clear them (permanently, if they’re reporting something simple like a loose gas cap). FIXD can provide a limited amount of live data on the vehicle’s operation. And if the check engine light pops on, FIXD will automatically send a notification to your phone, so you can learn what the trouble code is reporting and start thinking about what to do next. FIXD also provides scheduled maintenance reminders for the specific make and model, per the manufacturer’s recommendations, and advises when it might be time to check wear items like batteries, tires and wiper blades.
From there, the company will try to sell you its FIXD Premium monthly subscription, starting at $8.99 per month. Premium provides cost and repair estimates from the Identifix database and unlimited calls to a hotline staffed by ASE-certified mechanics. These folks can provide do-it-yourself advice or a second opinion on a service shop’s estimate.
Even without the subscription upgrade, FIXD will keep you posted on what’s happening inside your OBD2 vehicle and provide a trust gauge to help evaluate what a professional mechanic might be telling you.
The CarScan Advisor OBD2 scanner takes its cues from Innova’s more expensive OBD2 scanners. At $100 or less, it packs a lot of value into a dedicated scan tool for the price of a better Bluetooth/smartphone device.
CarScan Advisor code reader covers all the essentials: reading, deciphering and clearing check engine light trouble codes; battery tests and smog test evaluation; system diagnostics for ABS codes on most cars; and Freeze Frame data that captures what was going on when an error code was triggered. It displays a range of Live Data when a vehicle is running — RPM, fluid temperatures, fuel injection data — that can aid diagnosis in all cases.
This OBD2 scanner’s patented all-in-one screen is big and easy to read for the price. Everything is packaged in a large, rugged case. It comes with the same support and thorough manual as Innova’s more expensive scanners, as well access to the internet-connected Repair Solutions 2 app.
CarScan Advisor delivers a reliable, easy-to-master dedicated OBD2 scanner for a moderate investment. It’s a great choice for owners who plan to keep higher-mileage vehicles on the road indefinitely, and a good choice for hobbyists who buy and sell cars regularly — or for the person friends seek when they’re in the market for a used car.
The MaxiDiag MD808 code reader is built by a company known worldwide for professional automotive diagnostic equipment and products that compete with those manufactured by Bosch. Yet Autel also manufactures a line of consumer-oriented OBD2 scan tools, and the MaxiDiag MD808 is one of our favorites.
The MD808 is similar to our best overall pick, the Innova CarScan Pro, with pro-level features at a consumer-targeted price. That means all the essential reading of OBD2 codes, clearing and analyzing features and bidirectional control, which lets you target which systems will be analyzed and to disable or enable certain features built into the car builders’ control programs.
The MD808 OBD2 scanner is packaged in a more rectangular shape, which some people might prefer, and its hard plastic case is surrounded by a thick rubber grip that adds another layer of impact protection. On the downside, its screen is narrower than the CarScan Pro’s, and it has fewer keys. Operation can require an extra layer of menus.
Nonetheless, you won’t go wrong with the MaxiDiag MD808 scan tool. It’s everything an auto hobbyist is likely to need. It comes from a company with a professional history, known for good product support.
This compact OBD2 scanner is conventional in that it connects to a vehicle’s OBD2 port with a cable. With four keys and a simple menu, the Ancel BD310 delivers the basic functions every scan tool should. It also has a handy dash-vent attachment for easy, safe display while driving, and it can present a range of live operating data-temperatures, fuel use, spark advance and more while the vehicle is under load.
The “hybrid” part comes when you pair the BD310 scan tool to a smartphone via Bluetooth, then switch to operating it with Ancel’s app for Apple or Android. With the graphics capability of your smartphone, the BD offers even more data presented in various forms, including gauges and graphs. It can also record familiar trip-computer functions like average speed, time and fuel consumption. It offers strengths inherent to both dedicated OBD2 scanners and Bluetooth dongles in a single device.
Ancel builds a wide variety of automotive diagnostic equipment. Its BD310 OBD2 scanner is loaded with useful functions at a really reasonable price.
Anself sells a strange range of hundreds of products, from telescopic back scratchers to inexpensive condenser microphones to 60-watt solar panels to yoga balls straight outta China. Its OBD2 to USB cable is one of them.
Sound dicey? Maybe it is, but here’s what you get for your fourteen bucks: The cable, a manual and a CD with software that can turn your Windows laptop into an OBD2 scanner. The manual is not always easy to understand, but you can glean chunks of useful information. At the very least you can probably leverage the cable to run more familiar apps like Torque Pro for PC on your laptop, and that could provide most of the functions expected in an OBD2 scan tool and more.
The point? Twofold. First, devices like the Anself OBD2 to USB cable demonstrate what a Wild West scene the OBD2 scanner market can be. You can go with an established product, play it safe and spend more, and probably get what you pay for (including, with the right brands, good support). Or you can roll the dice and try some of the really cheap stuff that’s out there on the web.
We’re reasonably sure you could get the Anself OBD2 to USB cable to work to read a lot of the check engine light codes a vehicle generates, and clear them, and maybe even learn a bit more about what’s going on in the car. The consequences of failure probably aren’t catastrophic. The likely worst case is that you throw in the towel and bring your vehicle to a local auto parts store for a free code read. Again.
Is the potential upside worth $14? Are you feeling lucky today?
Comparison of the best OBD2 scanners in 2020
|The best OBD2 scanner overall||Innova||CarScan Pro 5610||$300||Everything a high-level do-it-yourselfer or car hobbyist is likely to need, with pro features, easy interface, a real manual and good support.|
|The best Bluetooth smartphone OBD2 scanner||BlueDriver||Pro OBD2 Scan Tool for iPhone & Android||$100||The same features as some pricier dedicated scanners, ranks potential fixes, delivers great smartphone graphics and active support.|
|The best OBD2 scanner if money is no object or if you’re a paid professional||Bosch||ADS 625 Diagnostic Scan Tool 3920||$4,450||Everything an OBD2 scanner can do. Includes a PC interface dock, front and rear cameras, NVH analyzer, volt meter, wiring diagrams, Bosch repair library and internet browser.|
|The best leave-it-in-all-the-time OBD2 Bluetooth dongle||FIXD||Car Sensor & Diagnostic App for iPhone and Android||$60||Solid basic scanner functions; sends push notifications to your phone when the check-engine light flashes and explains the fault.|
|The best dedicated OBD2 scanner on a budget||Innova||CarScan Advisor 5210||$100||Takes cues from the best overall scanner for a lot less. Solid foundation, easy interface, big screen and good support.|
|The best high-end consumer-class OBD2 scanner with a candy-bar grip||Autel||MaxiDiag MD808 Pro||$299||The same pro-grade features and function as best overall, packaged in a rectangular unit. Screen is narrower and interface takes a bit more work.|
|The best hybrid OBD2 scanner||Ancel||BD310 Bluetooth & Handheld OBD2 Scanner||$60||Compact basic dedicated scanner with unique dash mount for Live Data. Connects to a phone app via Bluetooth for cool graphics and bigger database.|
|The best OBD2 scanner option from the bottom of the barrel||Anself||OBD2 Scanner Cable with USB Connection for Windows||$14||Comes with a software disk that could turn your laptop into an OBD2 scanner. Should read codes and clear idiot lights.|
OBD2 car scanners 101
If this “onboard diagnostics” stuff sounds intimidating, the basics are actually fairly simple. It started in the 1990s, when the US government mandated that all vehicles beginning with the 1996 model year be equipped with a standard self-diagnostic system called OBD2 (for onboard diagnostics, generation 2), primarily to monitor emissions control systems. Since then, OBD2 has grown ever more sophisticated, monitoring ever more systems, but the process remains the same. When OBD2 records a problem, it creates a fault or diagnostic trouble code, then lights a warning on the vehicle dash (often that ubiquitous check engine light).
Fundamentally, an ODB2 scan tool reads and reports those trouble codes. It plugs into the car’s diagnostic block, often called the OBD2 port — an easy-to-identify, trapezoid-shaped female connector, noted in the owner’s manual and typically located under the dash or near the steering column. Then it scans the OBD2 system to find the faults or trouble codes.
Now, those codes are in fact codes, or five-place alphanumeric designations. Code P0420, for example, means the catalytic converter is not operating properly. The most rudimentary OBD2 scanners still simply report the error code, and you will have to check a reference manual or head for the internet to learn what P0420 means. But in 2020, the right, still modestly priced OBD2 scanner will tell you what the code definition is in English (or multiple languages) without having to look it up.
All OBD2 scanners should be able to clear the code, though the check engine light will likely flash again within a few miles if the actual problem generating the code hasn’t been fixed. And there are a lot of codes — upwards of 5,000 and more all the time, according to experts. Roughly 60% of those check engine codes are generic or universal, meaning they’re the same for all vehicles. P0420 means “catalytic converter not operating properly” no matter the brand or vehicle. Then there are a few thousand more codes specific to the vehicle manufacturer (such as Chevy, Ford or Toyota, and only Chevy, Ford or Toyota). A better OBD2 code reader will read the manufacturer codes, too, and explain those in English.
There’s much more a good OBD2 scanner can do with the data in your OBD2 system. Most will confirm the vehicle’s VIN and show you a Freeze Frame, or a rundown of key data points in the car at the moment the check engine trouble code was triggered, to help pinpoint what caused the problem. Most will report Live Data — a potentially long list of data points like fluid temperatures, engine speed and load, fuel injection and spark rate, sensor operation and so on while the car is running. It’s like the full set of gauges most cars no longer have, and then some, and another valuable diagnostic tool.
Many OBD2 scanners will conduct a simulated smog test, checking the same things a service shop will check before it signs off on a smog certificate, and give you a good idea if the car will pass or fail in its current condition. Some OBD2 scan tools allow you to evaluate the battery, alternator and ABS system. They’ll save or print reports with potential causes and possible repairs. The best can send commands to a car’s individual control modules and even turn them off and on. They let you make finite adjustments that the vehicle manufacturer allows in its control software and calibrate the tire pressure monitor system, or TPMS.
OBD2 scanners are less expensive than ever, but competition makes the supply side of the market wilder than ever. Anyone who has carefullywill understand. There’s a handful of established players, a bunch of upstarts and a vast expanse of noise. Even the respected companies will build essentially identical scanners with different model numbers and insignificant appearance changes to sell through different retailers (sometimes at different prices). Differences are sometimes hard to discern.
Depending on where you live and what you drive, a decent OBD2 scanner can pay for itself in relatively short order, if only through the fuel and time saved by avoiding trips to the local auto parts store for a free code read. OBD2 code readers don’t have to be expensive, but every car hobbyist or do-it-yourselfer should probably have one in the tool kit.
How we came up with our list
The list of the best OBD2 scanners above runs the gamut from the least expensive way to check engine trouble codes on your vehicle to excellent car enthusiast-type devices to a probably-too-expensive, full-professional mega scan tools. We evaluated reports from testing labs and scanned user ratings at popular shopping sites. We interviewed (harassed) experts, including Luke Daley at Innova and Jim Fish at BlueDriver, and we applied personal experience.
Before you choose an OBD2 code reader, consider the following pointers. And before you click “Confirm Order,” have a look at our pro tips below.
Two things to know before you buy an OBD2 scanner
1. Its primary purpose: What do you plan to do with an OBD2 scan tool? If you just want to know what that check engine idiot light in the dash is telling you, or you want to independently evaluate what a repair shop is reporting, and maybe turn the light off if it’s lit for something like a loose gas cap or a replaced EGR valve, you don’t need to spend much. Some $60-$80 will get you where you want to go, reliably and repeatedly. Even when the problem is solved, a basic OBD2 scanner remains a valuable tool if you or someone you know is looking for an inexpensive used car.
If, on the other hand, you’re an automotive enthusiast, a frequent do-it-yourself person or the friend nonenthusiasts come to for car advice, it’s certainly worth spending more. More expensive scanners can have broader make and model coverage. An OBD2 code reader with the right features will help you look deeper into a car’s control systems, troubleshoot problems and settle on appropriate repairs. A better one can help you analyze vehicle performance, optimize efficiency and better understand how a vehicle works.
Consumer-priced scanners today do things that were reserved for $5,000 pro-grade scanners just a couple of years ago. The best are good enough that, if you intend to make money fixing cars, you could use them to get started. Eventually, though, you’re probably going to need one of those expensive pro-grade models.
2. Which type works for you: Across the price spectrum, there are basically two types of OBD2 scanner. The dedicated hand-held scan tool is a self-contained device that plugs into the OBD2 port via cable (preferably long enough to reach from inside the car to the engine bay) and does its job. It has its own screen, buttons, software and computer chip.
The second type is a Bluetooth OBD2 scanner, known in the trade as a Bluetooth dongle. This type is usually a fairly small, plastic device that plugs into the OBD2 port and then connects to a smartphone or tablet via Bluetooth. Its job is to wirelessly transmit data from the vehicle’s OBD2 system to the phone, where that data is processed and presented by the dongle manufacturer’s control app. With a Bluetooth OBD2 scanner, the quality of its manufacturer’s software is paramount.
The primary advantage of the Bluetooth device, if it isn’t obvious: lower cost. Why pay for a screen and computer chip when your smartphone already has those? A Bluetooth OBD2 code reader dongle uses those components on your phone, where the screen and the chip are probably much higher quality than you need for this task.
If the typical cost advantage in a Bluetooth OBD2 scanner sounds like a no-brainer, you should consider the more subtle issues. Dedicated scanners are in important respects more efficient to use, and if you use the code reader regularly to diagnose check engine lights, or for longer sessions, speed and simplicity matter. With a self-contained scanner, you never have to worry about the quality of the Bluetooth connection, your phone charge or the strength of your Wi-Fi or cellular signal (the typical Bluetooth OBD2 scanner relies on access to internet databases). You won’t be interrupted by incoming calls or notifications while you’re using it. A good dedicated scanner is more impact-impervious than a smartphone, and drops are probably inevitable. What happens if your $1,000 phone falls in the engine bay and lands on the transaxle case, or gets wedged between a manifold and the engine block? Many Bluetooth scanners want to sell you upgrade subscriptions, and some of the apps have ads.
You can get a solid, dedicated OBD2 scan tool for $100 or less, so the choice isn’t as obvious as it might first appear. It probably goes back to the first thing you need to know when buying an OBD2 scanner: your primary purpose for doing so. And maybe how often you plan to use it.
The great majority of OBD2 scanners sold today will work on the great majority of vehicles built for model year 1996 and beyond. Yet for fairly arcane reasons, there are exceptions to this assumption of universal application (a few companies still build scanners for specific makes). Most reputable scan tool manufacturers have application checkers on their websites, so play it safe. When you think you know what scanner you want, check to ensure that it will work on cars you might regularly want to use it on. And if you plan to buy a Bluetooth-based scanner, there’s another potentially embarrassing mistake. The control apps that connect with the OBD2 dongle are specific to the operating system on the phone, tablet or PC that’s going to run the app. Some manufacturers have an app for Android or Apple, but not for other OSes, much less for Windows devices. Confirm that there’s an app that will work on your device.
There’s one more word of caution to note here. With some OBD2 scanners, some of the features or commands may not work on every make or model of automobile. This is largely a function of how the automakers build their control architecture or operating software. Some brands are just more particular about what they’ll let people see, and who they’ll let see it. This applies particularly with scanners that allow bidirectional control or adjustments within the vehicle’s control software. As a rule of thumb, US automakers generally allow the most access. Higher-end European brands allow the least. Again, you can sometimes learn something using the application checker on manufacturer websites. Often you can find the OBD2 scanner’s operating manual online, so look at that, too.
An OBD2 scanner is primarily intended to help figure out what might be wrong with a vehicle and then help get it fixed. It can reset certain parameters once the repairs are accomplished. More capable scanners can make finite adjustments in certain vehicle systems. An OBD2 scanner is not a flash programmer — a device that can actually rewrite the carmaker’s control code in search of more horsepower from the engine or different transmission shift points. Flash programmers are a thing, but they’re a different beast entirely, and typically auto-brand specific.
Finally, when it comes to OBD2 scanners, don’t underestimate the value of product support. Even the most confident do-it-yourself folk will have questions about what the code reader might be telling them, or something that doesn’t seem to be working as it should. Beyond limitations noted in the list, the manufacturers of our best scanners should be able to provide answers to your questions, and in reasonably short order.
Product support includes software updates. The reputable brands update their OBD2 scanner software regularly — at least once a year — so stay on top of it. The updates are usually easy to install, from a PC or over the air.
Written for Roadshow by J.P. Vettraino.