Best Car Health Monitors: Our Top Picks to Diagnose Your Car

Diagnose your car without the hassle of seeing a mechanic with an OBD-II scanner

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A surprisingly convenient feature that vehicles have developed over the years is the warning lights on the dashboard. Unfortunately, they’re often pretty vague and require a trip to the mechanic to find out the root cause. Luckily, you can purchase the same type of health monitor mechanics use to diagnose the problem. So now the question is, which OBD scanner is best?

  • Best Overall
    Innova 3100j OBD-II Diagnostic Tool
    When it comes to the useful features and most user-friendly design, this is the best car health monitor on the market.
    Works with both foreign and domestic vehicles to interpret the Check Engine, Airbag, ABS, and battery maintenance lights.
    Requires a subscription for a full diagnosis of your vehicle. More expensive than other monitors.
  • Best Value
    FIXD OBD-II Gen II Active Car-Health Monitor
    Both inexpensive and comprehensive, this product is a consumer favorite when it comes to car diagnostic devices.
    The free FIXD health monitor app helps make this a smart choice when it comes to smartphone OBD-II scanner capabilities.
    Does not come with a screen, so a phone is required for use. Only reads Check Engine lights.
  • Honorable Mention
    Foxwell NT301 OBD-II Diagnostic Code Reader 
    This car health monitor is ready to use out of the box and doesn’t require any charging or batteries since it is powered by the car.
    Large LED screen, a built-in library for definitions of certain technical terms, and free software updates when plugged into a computer.
    Only reads Check Engine lights and not compatible with every vehicle (there is a list of specific manufacturers that it works with).

Benefits of Car Health Monitor

  • Be in the know. Never be left guessing when it comes to dash lights. Even the least knowledgeable car owner can diagnose most issues at hand.
  • Never be overcharged. When you look up the issues your vehicle may have according to your OBD scanner, you’ll know exactly what needs to be fixed and how much it should cost.
  • Easy to use. Considering how much information the best OBD-II code readers can give you, it’s incredible that the only thing you need to do is plug it in. 
  • Save a trip. Some auto stores offer a health monitoring service—a few even offer it for free. But if you don’t have one near you or just don’t want to go to the store anytime there’s an issue, having one at home can be even more convenient. 

Types of Car Health Monitor


OBD is short for OnBoard Diagnostics. The system has actually been utilized in the average vehicle for decades now. The first iteration (OBD1) was replaced in the early 1990s, which is why OBD-II tools are much more common. 


By 1996, every vehicle manufactured officially adopted the newer OnBoard Diagnostic system. OBD-II is a massive improvement over its predecessor, offering much more accurate information. As these systems improved diagnostic capabilities, their codes became more complex. So today, that's why there is such a wide variety of diagnostic machines. 


The most common type of OBD-II device is a scanner that plugs into your vehicle and displays information on its built-in screen. These range from low price options, which can show any Check Engine code, to the premium price range, which have the ability to show a much larger variety of codes. 


The wireless OBD-II scanners—also referred to as Bluetooth or WiFi scanners in their descriptions—are small health diagnosis devices that stay plugged into the OBD port and send diagnostic information to your phone or computer.

Top Brands


Innova offers a wide range of plug-in car diagnostic tools, with each one offering useful features and the best OBD-II scanners. The company’s headquarters reside in Irvine, California. While Innova’s 3100j is our top pick, the company has the largest selection of car health monitor devices to meet anyone’s mechanical needs and budgetary restrictions; from the affordable 3030h to the premium 3160g.


Foxwell has been a leader in the automotive industry for more than a decade. It offers several different types of diagnostic tools, all of which have been hailed as reliable and innovative. The NT630 is one of the best OBDII scanners in the premium price range.


Located in Mountain View, California, Nonda is notable for making some of the best OBD-II Bluetooth adapters and best wireless OBD-II scanners. The ZUS is very popular due to its accessibility across multiple mobile platforms and a predictive algorithm that lets you know about potential issues before they happen.


Despite being a small startup company, Foseal has made a name for itself in recent years with its reliable and easy-to-use products. Its OBDII Scan Tool is often considered the best OBD-II scanner for iPhones. 

Car Health Monitor Pricing

  • $25 and below: The most basic monitors are small (usually Bluetooth-enabled) devices that require third-party health monitor apps or websites to diagnose your vehicle.
  • $40-$80: Some of the best OBD-II scanners for the money, in this price range you’ll typically see a plug-in device with a built-in screen and the ability to read Check Engine codes.
  • $100 and over: The higher price range of these car health monitors offer more features—the ability to read any dash light and full analyses to help plan mechanic costs.

Key Features

Check Engine Codes

Every OBD-II scanner can monitor Check Engine codes. The cheaper a product, the less they can do with the codes. Base model scanners can read a Check Engine light code and tell you what is triggering it. More advanced monitoring devices can detect the issue and clear or reset the code. The most expensive models can typically explain specific repair needs and estimated costs. 

Other Dash Lights

Some OBD-II scanners can only monitor Check Engine lights. More advanced devices can read any dash light your car may have. This includes ABS (or brake) lights, seatbelt lights, airbag lights, and battery maintenance lights. 

Data Logging

Whether your diagnostic tool is a Bluetooth-enabled monitor or a plug-in device, a lot of companies offer the ability to keep track of your vehicle's history of repairs. Data logs can show you trends, predict future issues, and keep track of the money spent fixing issues over the years.

Other Considerations

  • Compatibility: When it comes to an OBD scanner, it’s important to check if your specific vehicle is supported. Some scanners can only read certain manufacturer codes or can only work with certain model years. Luckily, almost every device has a list of applicable vehicles, so make sure you check that out before buying.
  • IOS or Android: While wireless OBD-II scanners usually have Bluetooth capabilities, they don’t necessarily have health monitor apps for your specific phone. The description will tell you which operating systems they are compatible with.
  • OBD-II: As mentioned, OBD-II is the standard for most vehicles. If your vehicle is older than 1996, has a diesel engine, or is all-electric, then many scanners will not work for you.

Best Car Health Monitor Reviews & Recommendations 2019

Best Car Health Monitor Overall: Innova 3100j OBD-II Diagnostic Tool

nnova 3100j OBD-II Diagnostic Tool

The 3100j is our top pick because this device beats the competition in terms of the number of issues it can diagnose. Not only can it read Check Engine lights, but it can also check ABS and SRS codes. If you've ever owned a used car that liked to surprise you with new dash lights all the time, you know how useful it can be to have that extra capability. 

The device is compatible with any car newer than 1996 and comes with an OBD-II plug. The company even offers free updates online, so your device will maintain its usefulness for many years to come. Innova also has a U.S.-based customer support team for any questions or concerns that come up.

The biggest drawback with this device is the optional subscription service required to use all of the features. This does not affect the scanner's ability to read codes and tell you the problem. The extra features include an online service that can detail what needs to be fixed, how much it will cost you, and how to do it yourself. If you don't care about that information, you can still use the tool.

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Best Value Car Health Monitor: FIXD OBD-II Gen II Active Car-Health Monitor

FIXD OBD-II Gen II Active Car-Health Monitor

By far one of the best Bluetooth OBD-II scanners, the FIXD device uses a dedicated app to work. One useful feature the app offers is the ability to keep track of multiple vehicles. For example, you can monitor the health of any vehicle you or family members drive. It keeps a log of all the problems that are detected related to the car's health and even recommends maintenance based on your mileage. 

When you're talking about Bluetooth-enabled monitors, it's pretty hard to beat how user-friendly this device is. The FIXD sensor plugs into your car's OBD-II port and doesn’t require any batteries. The app can display all the information about a check engine code in real-time without being restricted by the smaller screen competitive models have. 

With this being the least expensive option on the list, it isn't surprising that there are a few drawbacks. Like most OBD scanning devices, this one can only read and clear Check Engine codes. The lack of a screen can also be a turnoff if you don’t want to use your own phone each time an issue comes up.

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Best Car Health Monitor Honorable Mention: Foxwell NT301 OBD-II Diagnostic Code Reader 

Foxwell NT301 OBD-II Diagnostic Code Reader

If you're looking for the best OBD scanner without all the frills, Foxwell offers a compelling choice. The NT301 is excellent if you're looking for quick answers about a check engine light without the headache of visiting a mechanic.

Our honorable mention has a lot to offer but misses a couple of highlights other top products have. Foxwell's NT301 has a 3-inch color screen and includes lifetime free software updates. The device can clear codes, reset the monitors in your car, and even save records of your past codes without any need to connect to a computer. 

Like many other scanners, this model only reads Check Engine lights. It is more convenient than wireless scanners when it comes to a quick diagnosis since it doesn't require any other device to run (like a phone). This device is also much more affordable than higher-end scanners but doesn't come with the online support, extra code capability, or optional subscription service these scanners offer. 

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  • The OBD plug in your vehicle is almost always located under the dashboard on the driver’s side.
  • If your scanner translates a code, but you still don’t understand the issue, don’t be afraid to look up the details online. 
  • Make sure you know whether your OBD scanner can read the type of light your vehicle has. For example, if your device only reads Check Engine lights, and you have an ABS light on, you won’t get any diagnosis on that device.


Q: Does this scanner check the transmission?

A: Yes, as long as the issue throws a Check Engine light.

Q: Do I need to buy any additional plugs?

A: No, every OBD-II vehicle has the exact same OBD plug.

Q: Can these scanners be updated on a Mac?

A: Typically, these car health monitoring devices can only be updated on PCs. If they do work with Apple products, it will say so in the description.

Final Thoughts

OBD-II scanners are an excellent way to diagnose issues your vehicle may have. The best option overall is the Innova 3100j OBD-II Diagnostic Tool because of its advanced features. 

If you’re looking for a great value for your money, it’s tough to beat the FIXD OBD-II Gen II Active Car-Health Monitor's price. Have something to add? Feel free to comment below!