The best OBD-II scanners are essential tools that tap into your car’s onboard computer, giving you direct access to a wealth of diagnostic information. Whether you’re facing a perplexing dashboard warning light or suspecting a hidden mechanical issue, these scanners can decode your car’s signals, often pinpointing problems before they escalate. Using an OBD-II scanner empowers you to troubleshoot car troubles yourself, potentially saving significant costs on professional mechanic fees.
However, the world of OBD-II scanners can be overwhelming, especially for beginners. The sheer variety of models and features can make choosing the right one a daunting task. Having personally navigated this landscape and tested numerous OBD-II scanners over the years, we’ve gained valuable insights into which scanners truly deliver on their promises. We understand the need for effective diagnostics without breaking the bank, which is why we’ve focused on identifying not just the best, but also the cheapest OBD2 scanners that offer excellent value.
Our top pick, the Innova 6100P, stands out with its advanced features, including predictive diagnostics and repair guidance. For those prioritizing portability and wireless convenience, the Topdon TopScan offers impressive functionality in a compact Bluetooth design. Crucially, for budget-conscious users, the Launch CR529, priced around $40, proves that affordability doesn’t have to mean sacrificing essential diagnostic capabilities.
Below are our curated recommendations for the best OBD-II scanners available today, catering to various needs and budgets. Further down, we’ll delve into how OBD-II scanners work and demystify those enigmatic error codes, ensuring you have a comprehensive understanding to make the best choice for your car.
Tom Pritchard
Tom is the Tom’s Guide UK Phones Editor, with expertise spanning from the latest mobile hardware to essential apps. He’s also a passionate advocate for electric vehicles, bringing a wealth of tech and automotive knowledge to his reviews.
The Quick List: Best and Cheapest OBD2 Scanners
Here’s a quick rundown of the top OBD-II scanners you can buy now, based on our hands-on evaluations. Keep scrolling for detailed reviews of each, highlighting their strengths and features.
- Best Overall: Innova 6100P
- Best Mobile Scanner: Topdon TopScan
- Best Cheap Scanner: Launch CR529
- Best Rugged Scanner: Topdon Phoenix Lite 2
- Best Dual-Purpose Scanner: Ancel BD310
- Best Scanner with Companion App: Carly OBD-II Scanner
Innova 6100P best overall OBD2 scanner for comprehensive diagnostics
1. Innova 6100P – Best Overall OBD-II Scanner
This handheld OBD-II scanner offers a professional-grade experience, going beyond basic fault reading to provide in-depth diagnostics. Paired with the Innova app, it delivers detailed problem descriptions, identifies necessary parts, estimates repair costs, and even predicts potential future issues.
Read our in-depth review of Innova 6100P
Topdon TopScan best mobile OBD2 scanner for wireless diagnostics and performance checks
2. Topdon TopScan – Best Mobile OBD-II Scanner
The Topdon TopScan is a user-friendly Bluetooth scanner that sets up effortlessly and packs professional-level features into a compact design. It offers comprehensive diagnostics, repair guidance, parts lists, and predictive capabilities to anticipate upcoming car problems, all accessible wirelessly through your smartphone.
Explore the features of Topdon TopScan
Launch CR529 best cheap OBD2 scanner with lifetime updates and essential diagnostic functions
3. Launch CR529 – Best Cheap OBD-II Scanner
The Launch CR529 is a small yet powerful OBD-II scanner that provides all essential diagnostic functions and even some higher-end features usually found in more expensive models. Its $40 price point, combined with lifetime support and updates, makes it an exceptional value for money and the best cheap OBD2 scanner for budget-conscious users.
Discover why Launch CR529 is the best budget OBD2 scanner
Topdon Phoenix Lite 2 best rugged OBD2 scanner for professionals and enthusiasts needing durability
4. Topdon Phoenix Lite 2 – Best Rugged OBD-II Scanner
The Topdon Phoenix Lite 2 is built for durability, featuring a robust design ideal for both professional mechanics and DIY enthusiasts who need a scanner that can withstand tough environments. Beyond its ruggedness, it offers powerful diagnostic capabilities suitable for advanced users.
Learn more about the durable Topdon Phoenix Lite 2
Ancel BD310 best dual-purpose OBD2 scanner for dashboard augmentation and standard diagnostics
5. Ancel BD310 – Best Dual-Purpose OBD-II Scanner
The Ancel BD310 excels as a dual-purpose OBD-II scanner, functioning both as a standard diagnostic tool and as a supplementary dashboard display for real-time engine data. Its compact design, smartphone compatibility, and affordable price make it a versatile choice.
See the dual functionalities of Ancel BD310
Carly OBD-II Scanner best OBD2 scanner with companion app for customization and advanced features
6. Carly OBD-II Scanner – Best Scanner with a Companion App
The Carly OBD-II Scanner stands out with its exceptional companion app, offering extensive customization and professional-grade diagnostic tests, especially for VW, BMW, and Ford vehicles. Its user-friendly interface and powerful app features make it a top choice for tech-savvy car owners.
Explore the companion app features of Carly OBD-II Scanner
What are the Best and Cheapest OBD-II Scanners?
Why Trust Tom’s Guide? At Tom’s Guide, our team of expert reviewers rigorously tests and analyzes products to bring you unbiased and comprehensive recommendations. We dedicate hours to hands-on testing to ensure you get the most reliable advice. Learn more about our testing methodology.
Best OBD-II Scanner Overall: Innova 6100P
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1. Innova 6100P
The perfect OBD-II scanner to empower DIY mechanics with professional-level diagnostics.
Read our Expert Review of Innova 6100P
Specifications:
- Display/Size: Color/2.8 inches
- Bluetooth/Handheld: Yes/Yes
- I/M Readiness Test: Yes
- Displays Live Data: Yes
- Number of Keys: 9
- Warranty: 1 year
- Size: 7.2 x 3.4 x 1.1 inches
- Weight: 6.5 ounces
Reasons to Buy:
- Compact and highly portable
- Resets battery and oil life lights
- Offers both handheld and app-based diagnostics
- Provides repair instructions and parts information
Reasons to Avoid:
- Text-based interface may feel less intuitive for some users
- Keys require firm pressure to operate
During our hands-on testing, the Innova 6100P truly stood out for its ability to make even novice users feel like seasoned professionals. Its intuitive operation and comprehensive features bridge the gap between amateur and expert car diagnostics.
The 6100P excels in making complex diagnostic tasks accessible and efficient. While the initial setup is slightly more involved than some other scanners, it’s a straightforward process, and the scanner quickly becomes operational once connected to your car’s OBD port.
A key advantage of the Innova 6100P is its hybrid functionality, offering both a dedicated handheld scanner and a companion app. This versatility allows users to choose their preferred method of interaction. The app includes a particularly valuable predictive maintenance feature, alerting you to potential component failures in advance, which can be invaluable for proactive car maintenance and cost savings.
Considering its comprehensive feature set, the price of around $120 feels justified. The ability to access live data, read and clear fault codes, perform pre-inspection I/M readiness checks, and the convenience of a 72-inch cable are significant added benefits that enhance its overall value.
Read our full Innova 6100P review.
Best Mobile OBD-II Scanner: Topdon TopScan
2. Topdon TopScan
Unleash your car’s hidden potential with this mobile OBD-II scanner designed for in-depth diagnostics.
Read our Expert Review of Topdon TopScan
Specifications:
- Display/Size: None
- Bluetooth/Handheld: Yes/No
- I/M Readiness Test: Yes
- Displays Live Data: Yes
- Number of Keys: None
- Warranty: 2 years
- Size: 3.2 x 2.0 x 1.1 inches
- Weight: 2.6 ounces
Reasons to Buy:
- Exceptional diagnostic coverage for a wide range of car systems
- Real-time live data monitoring
- Unique performance indicators for vehicle efficiency
- Maintenance item monitoring
Reasons to Avoid:
- The Bluetooth transmitter module is relatively large
- Advanced features may require a subscription after the first year
Despite its unassuming appearance, the Topdon TopScan is a powerhouse of automotive diagnostic capabilities. This isn’t just a basic Bluetooth OBD-II adapter; it significantly surpasses the functionality of many competitors in its class.
Beyond standard fault code reading and I/M Readiness tests, the TopScan goes further, offering performance and efficiency checks. It can even estimate your car’s horsepower and torque, features rarely found in OBD-II scanners, especially at this price point.
Many OBD-II scanners costing ten times more lack the performance analysis features of the TopScan. Whether you’re aiming to optimize your car’s performance or simply ensure its roadworthiness, the Topdon TopScan is an invaluable tool to have in your garage.
Read our full Topdon TopScan review.
Best Cheap OBD-II Scanner: Launch CR529
3. Launch CR529
The Launch CR529 redefines value, offering top-tier OBD-II diagnostics at a remarkably affordable price, making it the best cheap OBD2 scanner on the market.
Read our Expert Review of Launch CR529
Specifications:
- Display/Size: Color/2.8-inches
- Bluetooth/Handheld: No/Yes
- I/M Readiness Test: Yes
- Displays Live Data: Yes
- Number of Keys: 8
- Warranty: 1 year
- Size: 6.5 x 3.8 x 1.2 inches
- Weight: 11 ounces
Reasons to Buy:
- Extremely inexpensive, providing exceptional value
- Lifetime free updates ensure long-term usability
- Easy-to-use pre-inspection report feature
Reasons to Avoid:
- Does not support manufacturer-specific specialty codes
- Feels somewhat heavy for its size
- Shorter 1-year warranty compared to some competitors
The Launch CR529 is arguably the best value OBD-II scanner you can buy. Its incredibly low price of around $38 is just the beginning; the level of diagnostic features packed into this scanner is truly surprising for the cost. We were genuinely impressed by how much functionality is offered at such an accessible price point, solidifying its position as the best cheap OBD2 scanner.
Of course, some compromises are expected at this price. The CR529 lacks support for manufacturer-specific codes and has a slightly hefty feel. However, it still delivers essential features like live data, instant inspection reports, and a comprehensive overview of your car’s systems. Crucially, lifetime updates ensure that this scanner remains a valuable tool for years to come, without any subscription fees.
While the CR529 may not cater to professional mechanics needing advanced, manufacturer-specific diagnostics, it’s an outstanding choice for the average car owner. For anyone looking for a reliable and affordable OBD-II scanner, the Launch CR529 is hard to beat.
Read our full Launch CR529 review.
Best Pro-Level OBD-II Scanner: Topdon Phoenix Lite 2
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4. Topdon Phoenix Lite 2
The Topdon Phoenix Lite 2 bridges the gap between amateur convenience and professional diagnostic power, offering advanced features in a user-friendly package.
Read our Expert Review of Topdon Phoenix Lite 2
Specifications:
- Display/Size: Color/8-inch
- Bluetooth/Handheld: Yes/Yes
- I/M Readiness Test: Yes
- Displays Live Data: Yes
- Number of Keys: Touchscreen
- Warranty: 2 years
- Size: 10.2 x 7.2 x 1.7 inches
- Weight: 2.6 pounds
Reasons to Buy:
- Offers near-professional level OBD scanning capabilities
- Hybrid design with handheld unit, Wi-Fi and Bluetooth connectivity
- Large and intuitive 8-inch touchscreen display
- Extensive array of diagnostic tests and live data options
- Includes adapters and a protective hard case
Reasons to Avoid:
- Bulky and heavy, potentially cumbersome in tight spaces
- Higher price point compared to standard OBD-II scanners
- Subscription required for updates after the initial two years
The Topdon Phoenix Lite 2 is a significant investment, costing more than many other capable OBD-II scanners. However, it delivers a wealth of features that justify the price for users needing advanced diagnostics. It’s ideally suited for both experienced DIYers and professional mechanics.
A standout feature is its wireless operation; the control tablet connects via Bluetooth to a receiver plugged into the OBD port, allowing for exceptional freedom of movement around the vehicle. While the scanner itself is substantial in size and weight, it includes a kickstand and a rugged build designed to withstand demanding workshop environments.
The Phoenix Lite 2 boasts advanced features like live data graphing, detailed fault code information, and numerous specialized diagnostic functions typically found only in high-end professional tools. Note that firmware updates are included for two years, after which a yearly subscription of $495 is required to maintain access to the latest features and updates.
Read our full Topdon Phoenix 2 Lite review.
Best Dual-Purpose OBD-II Scanner: Ancel BD310
Ancel BD310 compact and versatile OBD2 scanner that doubles as a car performance display](https://www.tomsguide.com/reviews/ancel-bd310)
5. Ancel BD310
The Ancel BD310 is a practical OBD-II scanner that serves a dual purpose, enhancing your car’s functionality beyond diagnostics.
Read our Expert Review of Ancel BD310
Specifications:
- Display/Size: Color/2 inches
- Bluetooth/Handheld: Yes/Yes
- I/M Readiness Test: Yes
- Displays Live Data: Yes
- Number of Keys: 4
- Warranty: 3 years
- Size: 5.1 x 2.4 x 0.6 inches
- Weight: 5.4 ounces
Reasons to Buy:
- Lightweight and highly compact for easy storage
- Functions as both an OBD-II scanner and a secondary car display
- Offers both handheld and Bluetooth scanning options
Reasons to Avoid:
- Minimalist interface may lack visual appeal for some users
- Small 2-inch screen can be limiting for data viewing
The Ancel BD310 stands out due to its dual functionality, operating as a standard handheld OBD-II scanner and, when connected to a smartphone via Bluetooth, as a supplementary display for your car’s vital engine stats. This unique capability adds extra value beyond typical diagnostic functions.
Its compact and lightweight design makes the BD310 exceptionally easy to store in your glovebox, ensuring it’s always within reach. The 2-inch display is admittedly small, and the four-button interface is basic, but these design choices contribute to its portability and don’t hinder its diagnostic effectiveness.
The 56-inch cable provides ample reach for comfortable use while working under the hood. The BD310 effectively performs essential OBD-II functions like I/M readiness tests and displays crucial performance data, including coolant temperature, engine timing, and RPM.
Read our full Ancel BD310 review.
Best Companion App: Carly OBD-II Scanner
Carly OBD-II Scanner sleek design with companion app offering extensive vehicle customization and diagnostics](https://www.tomsguide.com/vehicle-tech/carly-obd-scanner-review)
6. Carly OBD-II Scanner
The Carly OBD-II Scanner’s value is heavily dependent on your car make, but its companion app is a standout feature, offering unparalleled customization and diagnostic depth for supported vehicles.
Read our Expert Review of Carly OBD-II Scanner
Specifications:
- Display/Size: No Display
- Bluetooth/Handheld: Yes/No
- I/M Readiness Test: No
- Displays Live Data: Yes
- Number of Keys: None
- Warranty: Lifetime
- Size: 2.9 x 1.5 x 0.7 inches
- Weight: 0.7 ounces
Reasons to Buy:
- User-friendly and intuitive app interface
- Extensive customization options for supported car models
- Real-time live data display
- Covers maintenance and repair procedures
- Lifetime warranty and software updates
Reasons to Avoid:
- Feature availability varies significantly by car make and model
- App subscription can become costly for full functionality
The Carly OBD Scanner offers a compelling package, with the companion app being a major highlight. While many Bluetooth OBD-II scanners provide basic apps, Carly’s app is exceptionally well-designed and feature-rich, setting it apart from the competition.
Beyond basic fault diagnosis and clearing warning lights, the Carly app provides repair assistance, helping you get your car back on the road, and even includes features to assess used cars for potential issues before purchase. The lifetime warranty is a significant advantage, offering long-term peace of mind.
However, the functionality of the Carly scanner is heavily dependent on your car’s make and model. It’s particularly beneficial for owners of VW, BMW, and Ford vehicles, which enjoy the most comprehensive feature support. Before purchasing, it’s crucial to check the compatibility of your specific car model. Additionally, while the app is excellent, accessing features beyond basic OBD functions requires an ongoing subscription, which can add to the overall cost.
Read our full Carly OBD scanner review.
Other OBD-II Scanners We’ve Tested
Innova CarScan Mobile 1000 compact Bluetooth OBD2 scanner with predictive diagnostics and user-friendly app](https://www.tomsguide.com/reviews/innova-carscan-mobile-1000)
8. Innova CarScan Mobile 1000
Innovative diagnostic features in a remarkably compact Bluetooth design, perfect for on-the-go car health monitoring.
Read our Expert Review of Innova CarScan Mobile 1000
Specifications:
- Display/Size: None
- Bluetooth/Handheld: Yes/No
- I/M Readiness Test: Yes
- Displays Live Data: Yes
- Number of Keys: None
- Warranty: 1 year
- Size: 2.0x 1.5 x 1.0 inches
- Weight: 0.9 ounces
Reasons to Buy:
- Extremely easy and quick to set up
- Small and highly portable
- Excellent companion app with intuitive interface
- Predictive diagnostics and repair suggestions
- Functions as a standalone automotive gauge display
Reasons to Avoid:
- Requires using two separate apps for full functionality
- Both apps contain advertisements
The Innova CarScan Mobile 1000 is among the most innovative Bluetooth OBD-II scanners we’ve tested. Its effortless wireless setup and incredibly compact size are immediately appealing. It incorporates many of the advanced and user-friendly features found in Innova’s larger scanners, making professional-level diagnostics accessible in a pocket-sized device.
The CarScan Mobile 1000 offers a comprehensive suite of diagnostic features, including Innova’s predictive software that can identify potential issues before they become critical. It also provides part and repair suggestions, guiding you on the necessary steps to address any problems. Additionally, it can transform your smartphone into a customizable display of automotive gauges, providing real-time monitoring of vehicle performance.
Read the full Innova CarScan Mobile 1000 review.
9. ThinkCar ThinkDiag TKD01
A dependable OBD-II scanner with enhanced diagnostic capabilities, though it comes with a subscription after the first year.
Read our Expert Review of ThinkCar ThinkDiag TKD01
Specifications:
- Display/Size: None
- Bluetooth/Handheld: Yes/No
- I/M Readiness Test: Yes
- Displays Live Data: Yes
- Number of Keys: None
- Warranty: 1 year
- Size: 3.1 x 2.0 x 1.1 inches
- Weight: 2.7 ounces
Reasons to Buy:
- Capable of reading enhanced, manufacturer-specific diagnostic codes
- Offers a wide range of optional functions
- Includes a hard carry case for protection and portability
Reasons to Avoid:
- Requires a $40 app subscription after the first year for continued use
- Relatively heavy and bulky for a Bluetooth OBD-II scanner
- Initial setup can be somewhat complicated
The ThinkCar ThinkDiag TKD01 is one of the larger Bluetooth OBD-II scanners available, which can make installation in some vehicles a bit challenging. Its size may necessitate an extension cable in certain cars. However, the robust build of this oval-shaped module makes it highly durable.
The ThinkDiag app provides profiles for over 100 car manufacturers, making it excellent for accessing manufacturer-specific diagnostic trouble codes. It also reads extended fault codes and efficiently handles common issues like oil-change light resets and monitoring key vehicle systems. Similar to Innova scanners, the ThinkDiag offers predictive diagnostics but, unfortunately, does not provide repair advice.
Be aware that full access to ThinkDiag’s features is free for only the first year; continued access requires an annual subscription of at least $40.
Read our full ThinkCar ThinkDiag TKD01 review.
Autel AutoLink AL539 versatile OBD2 scanner with built-in multimeter for electrical system diagnostics](https://www.tomsguide.com/reviews/autel-autolink-al539)
10. Autel AutoLink AL539
Ideal for diagnosing both OBD-II system faults and electrical problems, offering a unique multimeter function.
Read our Expert Review of Autel AutoLink AL539
Specifications:
- Display/Size: Color/2.8 inches
- Bluetooth/Handheld: Yes/No
- I/M Readiness Test: Yes
- Displays Live Data: Yes
- Number of Keys: 8
- Warranty: 1 year
- Size: 6.7 x 3.6 x 1.4 inches
- Weight: 10.6 ounces
Reasons to Buy:
- Integrated electrical multimeter for diagnosing electrical issues
- Includes battery testing capabilities
- Comes with a built-in stand for convenient hands-free operation
Reasons to Avoid:
- OBD-II scanning and multimeter functions cannot be used simultaneously
- Internal battery requires charging
The Autel AutoLink AL539 distinguishes itself with a feature rarely seen in OBD-II scanners: a built-in multimeter for diagnosing electrical system problems. This allows you to identify issues like faulty wiring, shorts, alternator voltage problems, and blown fuses. A key limitation is that the multimeter cannot be used while the AL539 is connected as an OBD-II scanner.
As an OBD-II scanner, the AL539 displays a range of live data and performs comprehensive pre-inspection readiness tests. Faults are indicated with color-coded lights (red, yellow, green) for quick interpretation.
The AL539’s design is practical, featuring a compact and lightweight build, enhanced by a pull-out stand for hands-free use and a generous 58-inch cable. The interface is user-friendly, with icons for major functions simplifying navigation.
Read our full Autel AutoLink AL539 review.
Frequently Asked Questions About OBD-II Scanners
What is an OBD-II Scanner?
Mechanics use diagnostic scanners plugged into your car’s OBD port to understand car problems, rather than manually disassembling the engine. These OBD-II scanners access data from your car’s onboard computer.
Basic OBD-II scanners read and identify error codes flagged by your car when it detects an issue. More advanced scanners offer real-time system monitoring and can even predict potential future problems.
What is the OBD-II Port?
The On-Board Diagnostics Version Two (OBD-II) port is a standardized port found in almost all passenger vehicles sold in the United States since 1996, Canada since 1998, the European Union since 2004, and Australia, Mexico, and New Zealand since 2006.
This port is the interface point to your car’s onboard computer. Various devices, including OBD-II scanners, insurance telematics devices, and dash cams, can connect to this port.
If you’re unsure of your OBD-II port location, here’s a guide to finding your car’s OBD-II port for North American vehicles. For worldwide locations, see how to find your OBD-II/EOBD port globally.
What is a DTC?
DTC stands for Diagnostic Trouble Code. It’s an error code generated by a car’s OBD system when it detects a problem. OBD-II scanners read these codes, allowing users to diagnose car issues. Many DTC codes are standardized across vehicle makes and models, though some manufacturers use unique, proprietary DTCs.
What do DTCs Actually Mean?
DTCs may seem like random letters and numbers, but they follow a logical structure that indicates the type and location of the problem.
The first letter specifies the affected vehicle system: Powertrain (P), Body (B), Chassis (C), or Network (N). The second character is a number: 0 for generic codes, 1 for manufacturer-specific codes.
The third character identifies the specific subsystem:
- 1: Fuel and air metering
- 2: Injector circuit fuel and air metering
- 3: Ignition system or misfire
- 4: Auxiliary emissions controls
- 5: Vehicle speed controls and idle control systems
- 6: Computer auxiliary outputs
- 7, 8, 9: Transmission and gearbox faults
- A, B, C: Hybrid-specific propulsion faults
The fourth and fifth characters pinpoint the exact fault within the subsystem, ranging from 0 to 99.
OBD-II scanners translate these codes into understandable descriptions. Advanced models provide more detailed information. Online resources like Google can also help decipher DTCs. There are over 5,000 possible DTCs, covering a wide range of potential issues.
Not all DTCs indicate critical problems. Some may simply warn of minor issues, like a slightly elevated engine temperature.
How to Choose the Best and Cheapest OBD-II Scanner for You
If you want to understand your car’s health or diagnose issues, using one of the best OBD-II scanners is an effective approach.
This is the same method dealerships and repair shops use. Having this capability yourself is empowering. However, OBD-II scanners vary significantly. There are two main types:
Handheld OBD-II scanners come with an integrated screen and cable. Wireless OBD-II scanners connect to smartphones or tablets via Bluetooth.
Both types offer high-performance options under $200, and some are even under $30, making them accessible for most car owners looking for a cheap OBD2 scanner. Key considerations when choosing an OBD-II scanner include size, weight, and the ability to accurately read fault codes and live data. Here are crucial criteria:
- Easy Setup: A scanner should be quick to set up for timely diagnostics.
- Faults and Explanations: The best scanners explain fault codes, aiding DIY repairs or mechanic communication.
- I/M Readiness Check: Ensures your car passes emissions inspections.
- Accuracy: Reliable results are essential for effective diagnostics.
- Size and Weight: Portability is important for on-the-go use.
- Live Data: Helps diagnose intermittent issues by monitoring real-time parameters.
- Graphs: Visual data representation enhances analysis.
- Warranty: Longer warranties provide better value and peace of mind.
Choosing between a Bluetooth scanner and a handheld unit depends on personal preference. Consider whether you prefer using your smartphone screen or a dedicated device.
For long-term value, look for scanners with lifetime warranties or software updates to keep pace with automotive technology.
For handheld scanners, prioritize screen size and clarity, aiming for icon-based interfaces for ease of use. Rugged models with rubber bumpers are beneficial for durability.
Extra features like electrical multimeters, manufacturer-specific code reading, and PDF export capabilities can add significant value.
The affordability of sophisticated OBD-II scanners, with many professional-level options under $100 and excellent cheap OBD2 scanner choices available, makes them a worthwhile investment, often costing less than an hour of mechanic labor.
How We Test OBD-II Scanners
To evaluate OBD2 scanners, we conduct hands-on testing over several weeks, using a 2014 Audi A4 Allroad. Testing includes:
- VIN Verification: Confirming the scanner correctly reads the vehicle identification number (VIN).
- Connectivity: Testing Bluetooth or Wi-Fi connections for wireless scanners with devices like Apple iPad Pro, Microsoft Surface, or Samsung Galaxy S9+. Handheld scanners are tested for direct OBD-II port connection.
- Range and Cable Length: Measuring wireless range and cable length for practical usability.
- Live Data Monitoring: Observing engine and system data in real-time with the car running.
- Fault Code Generation and Reading: Simulating a fault by disconnecting the engine oil temperature sensor, then using the scanner to read and interpret the fault code.
- Fault Code Clearing: Verifying the scanner’s ability to clear the fault code and turn off the check engine light after resolving the simulated issue.
- Road Testing: Assessing the scanner’s ability to display operational data like engine speed, timing, and coolant temperature while driving, noting data presentation (numbers, graphs, gauges).
We rigorously assess each scanner’s performance, ease of use, and feature set to provide reliable recommendations.
Understanding fault codes is crucial. All codes consist of five characters: a letter followed by four numbers. The letter indicates the system (Powertrain, Body, Chassis, or Undefined). The initial number after the letter indicates whether it’s a generic (0) or manufacturer-specific (1) code.
For example, a P0098 code typically indicates an issue with the intake air temperature sensor. A Ford-specific P1112 code for the same sensor suggests intermittent readings, requiring sensor replacement. Understanding these codes, aided by a good OBD-II scanner, empowers you to diagnose and address car issues effectively.
