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Which OBDII scanners are best?

Those annoying dashboard warning lights only tell you that something is wrong. They don’t tell you that the problem could be anything from a loose gas filler cap to a serious engine problem ready to cause great damage.

OBDII scanners plug into a port under your vehicle’s dashboard, “talk” to your car’s sensors, diagnose the problem and show you error codes on a screen. They work with all newer vehicles and allow you to diagnose problems on your own. If you’re interested in a large-screen OBDII scanner that displays severity alerts that tell you when your car needs immediate attention, try the INNOVA 6030P Code Reader and Scanner, which also tests your battery and alternator.

What to know before you buy an OBDII scanner

Types of scanners and how they work

OBD stands for on-board diagnostics. Since 1996, OBDII scanners are compatible with all cars, trucks and SUVs through an industry-standard port. Most scanners connect by a 16-pin plug to the OBDII port in your car. More sophisticated models connect to your smartphone, tablet or laptop via Bluetooth or other wireless connection to download data.

Error codes

All OBDII scanners generate error codes. Basic OBDII scanners stop there, but high-quality models go a step further by displaying troubleshooting information. This adds value and saves time, too.

To learn even more about OBDII scanners, take a look at the full OBDII scanner buying guide from

What to look for in a quality OBDII scanner

VIN retrieval

A scanner can retrieve your vehicle information number, which is a 17-digit code assigned when the vehicle is built. It’s visible on the dashboard in front of the steering wheel. The VIN uses a unique series of numbers and letters to identify your exact car’s make, model, year, engine size and where the vehicle was made. Think of it as your car’s fingerprint.


Look for an OBDII scanner that has a screen large enough to show more information than bare-bones models that show only an error code. OBDII scanners that show troubleshooting information use larger screens to do so.


Some companies that make and sell OBDII scanners have created companion apps that allow your vehicle data to be stored on your smartphone, tablet or laptop. Look for apps that allow you to access detailed diagnostic and troubleshooting information from the cloud.

Live data

Most scanners only work when your vehicle is turned off. Some OBDII scanners can read and measure live data while you drive. This is real-time performance data that you can download to your computer or smartphone.

Inspection and maintenance readiness

Many states require regular vehicle inspections of some kind. These almost always include safety and emissions. The number and type of required inspections fluctuate according to state and municipal laws and regulations. OBDII scanners with inspection and maintenance features allow you to pretest your car so you can fix problems before your inspection and pass your tests with flying colors.

How much you can expect to spend on an OBDII scanner

Basic handheld OBDII scanners that check for only the most basic problems and provide no troubleshooting information cost between $20 and $50. Scanners costing anywhere from $50 to $150 can diagnose more problems and are ideal for hands-on amateur mechanics and troubleshooters. Handheld OBDII scanners from $150 up to $1,000 have all the bells and whistles.

OBDII scanner FAQ

How do I find my car’s scanner port?

A. Like your VIN, your scanner port is to the left of the steering column. Unlike your VIN that’s located on the top of your dashboard, your car’s scanner port is beneath the dashboard and requires you to get down low to see it. When in doubt, check your vehicle owner’s manual.

I’m no mechanic, so why would I want an OBDII scanner?

A. If you have ever taken your car in for service due to a warning light, only to find nothing more was wrong than your gas cap wasn’t properly tightened, you were probably frustrated by having to go to a lot of trouble over nothing. With an OBDII scanner, you can see that all you need to clear your warning light is to give your gas cap another twist.

What are the best OBDII scanners to buy?

Top OBDII scanner

INNOVA 6030P Code Reader and Scanner

INNOVA 6030P Code Reader and Scanner

What you need to know: Use this large-screen OBDII scanner to check out what your dashboard lights aren’t telling you.

What you’ll love: This OBDII scanner is 10 by 7 by 2 inches and not only tells you the error code but also displays severity alerts that tell you in real-time when your car needs immediate attention. Another great feature of this 12-ounce OBDII scanner is that it tests your battery, alternator and charging system.

What you should consider: If you have a large truck, you should check to see if it’s compatible. Otherwise, this OBDII scanner works with most 1996 and newer cars and light trucks.

Where to buy: Sold by Amazon

Top OBDII scanner for the money

Bosch Automotive Tools OBD 1000 Diagnostic Vehicle Scanner

Bosch Automotive Tools OBD 1000 Diagnostic Vehicle Scanner

What you need to know: This affordable OBDII scanner has readings that are easy for non-mechanics to understand.

What you’ll love: This scanner gives you the ability to quickly determine the cause of your dashboard Check Engine light coming on. There’s no longer the need to go to the dealership for a minor problem that’s easy to correct. The scanner works with OBDII-compliant vehicles as old as 1994 models and reports on their emissions status.

What you should consider: The menus and features are what you would expect from a budget OBDII scanner.

Where to buy: Sold by Amazon

Worth checking out

Actron CP91245 C PocketScan Code Reader

Actron CP91245 C PocketScan Code Reader

What you need to know: This backlit OBDII scanner is an inexpensive model with an easy-to-understand interface.

What you’ll love: The scanner displays a wealth of data, including emissions status, fluid temperatures, intake air, voltages and engine load and RPM. This compact unit fits in your hand and connects quickly and easily to determine the causes of engine warning lights.

What you should consider: It’s bigger and heavier than most other scanners.

Where to buy: Sold by Amazon

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David Allan Van writes for BestReviews. BestReviews has helped millions of consumers simplify their purchasing decisions, saving them time and money.

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