The check engine light is on, and a wave of dread washes over you. Is it a major engine problem? A minor sensor glitch? Instead of rushing to an expensive mechanic, what if you could understand the issue yourself, right from your driveway? That’s the power of the Best Auto Code Scanners. These ingenious devices connect to your car’s onboard computer, unlocking a wealth of diagnostic information. Whether you’re a seasoned DIYer or a new car owner, an auto code scanner can save you time, money, and unnecessary stress.
Not all auto code scanners are created equal, and the sheer variety on the market can be overwhelming. We understand. We’ve spent years testing a wide array of scanners, from basic models to professional-grade tools. Our hands-on experience means we know exactly which auto code scanners deliver real value and performance. Keep reading to discover our top recommendations and learn how these scanners work, demystifying those perplexing error codes.
Among our top performers, the Topdon TopScan stands out as a remarkably user-friendly wireless option with impressive diagnostic capabilities. For budget-conscious users, the Launch CR529 offers exceptional features at an affordable price. And for those seeking a professional-level diagnostic experience, the Topdon Phoenix Lite 2 provides advanced functionality, albeit at a premium cost.
Below are our curated selections for the best auto code scanners available today.
Tom Pritchard
Tom is the UK Phones Editor at Tom’s Guide, with extensive experience in reviewing consumer technology and a passion for electric vehicles. His expertise ensures reliable and insightful product assessments.
Top Picks: The Best Auto Code Scanners at a Glance
This quick list highlights our top-rated auto code scanners, based on rigorous hands-on testing. Continue scrolling for detailed reviews of each product and insights into their standout features.
1. Topdon TopScan: Best Mobile Auto Code Scanner
Effortless Bluetooth setup combined with professional-grade features in a compact design. Enjoy comprehensive diagnostics, repair guidance, parts information, and predictive analysis for proactive car maintenance.
Explore the Topdon TopScan in Detail
2. Launch CR529: Best Budget-Friendly Auto Code Scanner
Compact and powerful, the Launch CR529 delivers essential OBD-II scanner functions alongside advanced features typically found in higher-priced models. Benefit from lifetime support and updates, offering incredible value for your money.
Discover the Launch CR529’s Value
3. Topdon Phoenix Lite 2: Best Rugged Auto Code Scanner for Professionals and DIYers
Built with a durable, horizontal design reminiscent of a Nintendo Switch, this robust scanner is engineered for both professionals and car enthusiasts. Experience powerful diagnostics in a device built to withstand demanding environments.
Learn More About the Topdon Phoenix Lite 2
4. Ancel BD310: Best Dual-Purpose Auto Code Scanner and Dashboard Display
The Ancel BD310 excels as both an OBD-II scanner and a supplementary dashboard display, offering engine specifications and diagnostic data in one device. Enjoy a sleek design, smartphone compatibility, and exceptional value.
Explore the Ancel BD310’s Dual Functionality
5. Carly OBD-II Scanner: Best Auto Code Scanner with Companion App
Maximize the potential of the Carly OBD-II Scanner with its exceptional companion app, particularly beneficial for VW, BMW, and Ford owners. Access extensive customization and professional-grade testing features through an intuitive app interface.
Discover the Carly OBD-II Scanner and App
In-Depth Reviews: Finding the Best Auto Code Scanner for Your Needs
Why Trust Tom’s Guide? Our dedicated team of writers and editors rigorously test and analyze products to deliver unbiased and helpful recommendations. Learn more about our testing methodology.
1. Topdon TopScan: Best Mobile Auto Code Scanner
(Image credit: Topdon)
Topdon TopScan Review: Unleash Your Car’s Hidden Potential
Our Expert Review:
Key Specifications:
- Display/size: None (App-based)
- Bluetooth/handheld: Yes/No
- I/M Readiness test: Yes
- Live data display: Yes
- Number of keys: None (App-controlled)
- Warranty: 2 years
- Size: 3.2 x 2.0 x 1.1 inches
- Weight: 2.6 ounces
Reasons to Buy:
- Excellent vehicle diagnostic coverage
- Real-time live data monitoring
- Unique performance indicators
- Comprehensive maintenance item coverage
Reasons to Consider:
- Larger transmitter size
- Subscription required for some features after the first year
Don’t let its unassuming appearance fool you; the Topdon TopScan is a powerhouse in a compact form. This Bluetooth-enabled auto code scanner goes beyond basic error code reading. It offers in-depth diagnostics, performance assessments, and efficiency checks that rival scanners in higher price brackets. Beyond standard fault detection and I/M Readiness tests, the TopScan provides performance metrics, including estimated horsepower and torque. Whether you’re aiming to optimize your car’s performance or ensure its roadworthiness, the TopScan is an invaluable tool for your garage.
Read our comprehensive Topdon TopScan review
2. Launch CR529: Best Cheap Auto Code Scanner
(Image credit: Future)
Launch CR529 Review: Unbeatable Value Under $50
Our Expert Review:
Key Specifications:
- Display/size: Color/ 2.8-inches
- Bluetooth/handheld: No/Yes
- I/M Readiness test: Yes
- Live data display: 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 affordable
- Lifetime update availability
- Convenient pre-inspection report feature
Reasons to Consider:
- Limited manufacturer-specific codes
- Heavier handheld feel
- 1-year warranty
The Launch CR529 redefines value in auto code scanners. Priced under $50, it delivers a surprising array of diagnostic capabilities. While compromises exist, such as the absence of manufacturer-specific codes and a slightly hefty build, the CR529 excels in essential functions. It offers real-time data, instant inspection reports, and a detailed view into your car’s internal systems. Lifetime updates ensure long-term usability without subscription fees. While professional mechanics might seek more advanced tools, the CR529 is an excellent choice for everyday car owners seeking a reliable and budget-friendly auto code scanner.
Read our in-depth Launch CR529 review
3. Topdon Phoenix Lite 2: Best Professional-Grade Auto Code Scanner
(Image credit: Future)
Topdon Phoenix Lite 2 Review: Bridging the Gap Between DIY and Professional Diagnostics
Our Expert Review:
Key Specifications:
- Display/size: Color/8-inch Touchscreen
- Bluetooth/handheld: Yes/Yes
- I/M Readiness test: Yes
- Live data display: Yes
- Number of keys: Touchscreen interface
- Warranty: 2 years
- Size: 10.2 x 7.2 x 1.7 inches
- Weight: 2.6 pounds
Reasons to Buy:
- Professional-level OBD scanner capabilities
- Versatile handheld with Wi-Fi and Bluetooth connectivity
- Large 8-inch touchscreen display
- Extensive suite of diagnostic tests and live data options
- Includes adapters and protective hard case
Reasons to Consider:
- Bulky, heavy, and can be cumbersome
- Higher price point
- Subscription required after two years for updates
The Topdon Phoenix Lite 2 represents a significant step up in auto code scanner technology. While pricier than many consumer models, it delivers near-professional diagnostic power suitable for both experienced mechanics and serious DIY enthusiasts. Its wireless design, with a Bluetooth-connected control pad, offers exceptional freedom of movement around the vehicle. Despite its robust and somewhat heavy build, the Phoenix Lite 2 features a kickstand and rugged construction designed for workshop environments. Advanced features like live data graphing and comprehensive fault information set it apart from basic scanners. However, be mindful of the subscription requirement for updates after the initial two years.
Explore our full Topdon Phoenix 2 Lite review
4. Ancel BD310: Best Dual-Function Auto Code Scanner
Ancel BD310 (Image credit: Tom’s Guide)
Ancel BD310 Review: Two Tools in One for Enhanced Vehicle Insight
Our Expert Review:
Key Specifications:
- Display/size: Color/2 inches
- Bluetooth/handheld: Yes/Yes
- I/M Readiness test: Yes
- Live data display: 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 compact design
- Functions as both a scanner and a secondary car display
- Offers handheld and Bluetooth scanning capabilities
Reasons to Consider:
- Minimalist interface design
- Small screen size
The Ancel BD310 provides versatility by serving as both a traditional handheld auto code scanner and a Bluetooth-enabled device that can project engine data onto your smartphone. Its compact and lightweight design makes it easily storable in a glovebox. While the 2-inch screen is small and the four-button interface is somewhat basic, it remains user-friendly for car diagnostics. The 56-inch cable offers ample reach, and the BD310 supports essential functions like I/M readiness tests and performance data display, including coolant temperature, engine timing, and RPM.
Read our detailed Ancel BD310 review.
5. Carly OBD-II Scanner: Best Auto Code Scanner with App Integration
(Image credit: Carly)
Carly OBD-II Scanner Review: App-Driven Diagnostics Tailored to Your Car
Our Expert Review:
Key Specifications:
- Display/Size: None (App-based)
- Bluetooth/Handheld: Yes/No
- I/M Readiness Test: No
- Live data display: Yes
- Number of keys: None (App-controlled)
- Warranty: Lifetime
- Size: 2.9 x 1.5 x 0.7 inches
- Weight: 0.7 ounces
Reasons to Buy:
- User-friendly app interface
- Extensive customization options
- Real-time live data display
- Coverage of maintenance and repair procedures
- Lifetime warranty and updates
Reasons to Consider:
- Feature availability varies by car model
- App subscription can be costly for advanced features
The Carly OBD Scanner stands out with its exceptional companion app, offering a superior user experience compared to many Bluetooth scanners. Beyond basic diagnostics, the app provides repair assistance, used car checks, and a range of customization settings. A lifetime warranty adds further value. However, feature compatibility is car-dependent, and accessing advanced functions beyond basic OBD requires a subscription, which can increase the overall cost. For users with compatible vehicles, particularly VW, BMW, and Ford, the Carly offers a powerful and app-centric auto code scanning experience.
Explore our full Carly OBD scanner review
Other Auto Code Scanners We Evaluated
- Innova CarScan Mobile 1000 (★★★★☆): An innovative Bluetooth scanner with predictive diagnostics and a simple setup. Read the Innova CarScan Mobile 1000 review
- ThinkCar ThinkDiag TKD01 (★★★★☆): A robust Bluetooth scanner with manufacturer-specific codes and error-fixing capabilities. Read the ThinkCar ThinkDiag TKD01 review.
- Autel AutoLink AL539 (★★★☆☆): Designed for electrical diagnostics with a built-in multimeter, plus live data and inspection readiness checks. Read the Autel AutoLink AL539 review
Frequently Asked Questions About Auto Code Scanners
What is an Auto Code Scanner?
Auto code scanners, also known as OBD-II scanners, are diagnostic tools that mechanics and car owners use to understand vehicle problems. They connect to your car’s OBD port, accessing the onboard computer’s data. Basic scanners read and interpret error codes (DTCs) indicating issues. Advanced models offer real-time system monitoring and predictive diagnostics.
What is the OBD-II Port?
The OBD-II (On-Board Diagnostics Version Two) port is a standardized interface found in most passenger vehicles sold in the US since 1996, and in other regions subsequently. It allows devices like auto code scanners, insurance trackers, and dashcams to interface with the car’s computer. Find your car’s OBD-II port location for North American cars. For worldwide locations, find your OBD-II/EOBD port here.
What is a DTC (Diagnostic Trouble Code)?
A DTC, or Diagnostic Trouble Code, is an error code generated by your car’s OBD system when it detects a problem. Auto code scanners read these codes to help users diagnose vehicle issues. While many DTCs are standardized across manufacturers, some are manufacturer-specific.
Understanding DTC Meanings:
DTCs may seem cryptic, but they follow a logical structure. The first character indicates the affected system: Powertrain (P), Body (B), Chassis (C), or Network (N). The second character denotes code type: generic (0) or manufacturer-specific (1). The third character specifies the subsystem:
- 1: Fuel and air metering
- 2: Injector circuit fuel and air metering
- 3: Ignition system or misfire
- 4: Auxiliary emissions
- 5: Vehicle speed and idle control
- 6: Computer auxiliary outputs
- 7, 8, 9: Transmission/gearbox faults
- A, B, C: Hybrid propulsion faults
The fourth and fifth characters pinpoint the exact fault (00-99). Auto code scanners translate these codes into descriptions, with advanced models providing more detail. Online resources like Google can also help decipher DTCs. Note that not all DTCs indicate critical problems; some may signal minor issues like slightly elevated engine temperature.
Choosing the Best Auto Code Scanner: Key Considerations
Using an auto code scanner is the most effective way to understand your vehicle’s health and diagnose issues. It’s the same technology used by dealerships and repair shops, empowering you with valuable information. Auto code scanners come in two main types:
- Handheld Scanners: Feature an integrated screen and OBD port cable.
- Wireless Scanners: Plug into the OBD port and connect to smartphones or tablets via Bluetooth.
High-quality auto code scanners are available for under $200, with some basic models under $30. Key features to consider when selecting the best auto code scanner include:
- Easy Setup: A quick and straightforward setup process ensures you’ll use the scanner promptly when needed.
- Fault Codes and Explanations: The scanner should not only display fault codes but also provide clear explanations for effective diagnosis.
- I/M Readiness Check: Essential for emissions testing, this feature verifies if your car will pass inspection.
- Accuracy: Reliable and accurate results are paramount for effective troubleshooting.
- Size and Weight: A compact and lightweight scanner is more likely to be kept in your car for on-the-go diagnostics.
- Live Data: Real-time monitoring of engine parameters helps identify intermittent issues.
- Graphs: Visual data representation enhances analysis, especially for comparing data over time.
- Warranty: Opt for scanners with extended or lifetime warranties for long-term reliability.
When choosing, consider whether you prefer a handheld scanner with a built-in screen or a wireless model that uses your smartphone. Prioritize features like lifetime updates and warranties to ensure your scanner remains current and reliable. For handheld scanners, a large, clear, icon-based display is beneficial. Rugged models with shock absorption are ideal for rough handling. Extra features like multimeters, manufacturer-specific code reading, and PDF export capabilities can also be valuable. With professional-grade auto code scanners available for under $100, it’s a cost-effective investment compared to mechanic labor fees.
Our Auto Code Scanner Testing Methodology
To evaluate auto code scanners, we used a 2014 Audi A4 Allroad over several weeks, testing in both garage and road conditions. Each scanner was connected to the car’s OBD-II port to verify VIN reporting. Wireless scanners were paired with devices like Apple iPad Pro, Microsoft Surface, and Samsung Galaxy S9+. Handheld scanner cord lengths and wireless ranges were measured. Engine performance and vital systems were monitored with the car running. To test fault detection, the engine’s oil temperature sensor was intentionally disconnected. Scanner details were assessed, the sensor issue was resolved, and error codes were cleared. Road tests were conducted to evaluate live data display, including engine speed, timing, and coolant temperature, noting data presentation as numbers, graphs, or gauges. Scanner accuracy and ease of use in diagnosing and interpreting fault codes were key evaluation factors. Understanding fault code structure is essential: codes consist of a letter prefix (Powertrain, Body, Chassis, Undefined) and four numbers. Generic codes (starting with 0) apply broadly, while manufacturer-specific codes (starting with 1) indicate specialized issues. For example, P0098 indicates a generic intake air temperature sensor problem, while a Ford-specific P1112 code points to intermittent intake air temperature sensor readings requiring replacement.
