Unraveling the complexities of your vehicle can often feel like deciphering a cryptic code, especially when that ominous check engine light illuminates on your dashboard. Modern cars are sophisticated machines, constantly monitoring their own health, and when something deviates from the norm, your car’s onboard computer logs it. The key to understanding these hidden messages? The Best Auto Scan Tool, also known as an OBD-II scanner. This invaluable device acts as your car’s translator, connecting to its computer and revealing the diagnostic information you need to understand what’s going on under the hood.
Whether you’re a seasoned car enthusiast or a first-time car owner, the prospect of diagnosing car problems yourself can feel daunting. However, with the right auto scan tool, you can empower yourself to understand your car’s issues, potentially saving money on expensive mechanic visits and gaining valuable insights into your vehicle’s performance.
Over the years, we’ve rigorously tested a wide array of auto scan tools, from basic code readers to professional-grade diagnostic systems. This hands-on experience allows us to confidently guide you towards the best auto scan tool for your needs and budget. Keep reading to discover our top recommendations and gain a deeper understanding of how these tools work and what those cryptic error codes actually mean.
Here are our top selections for the best auto scan tools currently available on the market.
Tom Pritchard
Tom is the Tech Editor, covering a wide range of consumer technology and automotive tech. He has extensive experience testing and reviewing OBD-II scanners and other car accessories.
Quick Picks: Top Auto Scan Tools
Based on our extensive hands-on testing, here’s a quick overview of the best auto scan tools you can purchase right now. Scroll down for detailed reviews and insights into each product.
Topdon TopScan mobile auto scan tool for comprehensive diagnostics1. Topdon TopScan
This Bluetooth-enabled auto scan tool is incredibly user-friendly and packed with features usually found in professional-grade devices. It offers in-depth diagnostics, repair guidance, parts information, and even predictive analysis to anticipate potential issues.
Launch CR529 OBD-II scanner, best value for money2. Launch CR529
The Launch CR529 is a compact yet powerful auto scan tool that delivers exceptional value. For an affordable price, it provides essential diagnostic functions and even some advanced features typically found on more expensive scanners. Plus, it includes lifetime support and updates, making it a smart investment.
Topdon Phoenix Lite 2 professional-grade auto diagnostic scan tool3. Topdon Phoenix Lite 2
The Topdon Phoenix Lite 2 boasts a robust, tablet-like design and offers a near-professional diagnostic experience. It’s designed for both experienced mechanics and car enthusiasts seeking a powerful and durable auto scan tool capable of withstanding tough workshop environments.
Ancel BD310 dual-purpose car diagnostic scanner and dashboard display4. Ancel BD310
The Ancel BD310 stands out as a versatile auto scan tool that not only performs diagnostics but can also function as a supplementary dashboard display, showing real-time engine data. It’s compact, user-friendly, and reasonably priced.
Carly OBD-II Scanner with companion app for advanced vehicle customization5. Carly OBD-II Scanner
The Carly OBD-II Scanner’s effectiveness is highly dependent on your car’s make, with brands like VW, BMW, and Ford enjoying the most comprehensive features. However, it’s renowned for its exceptional companion app, offering extensive customization options and professional-level testing capabilities.
Deep Dive: The Best Auto Scan Tools in Detail
Tom’s Guide’s commitment to providing trustworthy reviews means our writers and editors dedicate significant time to evaluating products and services to help you make informed decisions. Learn more about our rigorous testing and review process.
Best Mobile Auto Scan Tool
(Image credit: Topdon)
1. Topdon TopScan
Ideal for in-depth vehicle diagnostics and performance analysis
Read our expert review:
Key Specifications
- Display/Size: None (App-based)
- Bluetooth/Handheld: Yes/No
- I/M Readiness Test: Yes
- Live Data Display: Yes
- Keys: None (App-based)
- Warranty: 2 years
- Size: 3.2 x 2.0 x 1.1 inches
- Weight: 2.6 ounces
Reasons to Buy
- Extensive vehicle diagnostic coverage
- Real-time live data monitoring
- Unique performance metrics
- Broad range of maintenance functions
Reasons to Consider
- Larger transmitter size
- Some advanced features require a subscription after the first year
The Topdon TopScan may have a deceptively simple appearance, but beneath its compact exterior lies a powerful and versatile auto scan tool. This isn’t just a basic Bluetooth OBD-II adapter; it goes far beyond the capabilities of many competitors in its class. We were particularly impressed by its ability to not only identify faults and perform essential I/M Readiness tests but also to delve into vehicle performance and efficiency metrics.
The TopScan can even estimate your car’s horsepower and torque – features rarely found in even significantly more expensive auto scan tools. Whether you’re looking to optimize your car’s performance or simply ensure it remains in top running condition, the Topdon TopScan is an invaluable addition to your automotive toolkit.
Read our comprehensive Topdon TopScan review
Best Cheap Auto Scan Tool
(Image credit: Future)
2. Launch CR529
An exceptional OBD-II scanner offering remarkable value under $50
Read our expert review:
Key Specifications
- Display/Size: Color/ 2.8-inches
- Bluetooth/Handheld: No/Yes
- I/M Readiness Test: Yes
- Live Data Display: Yes
- Keys: 8
- Warranty: 1 year
- Size: 6.5 x 3.8 x 1.2 inches
- Weight: 11 ounces
Reasons to Buy
- Highly affordable
- Lifetime free updates
- Convenient pre-inspection report feature
Reasons to Consider
- Lacks manufacturer-specific codes
- Heavier than some competitors
- 1-year warranty is shorter than some
In our assessment, the Launch CR529 stands out as the best value auto scan tool currently available. Its incredibly low price point of around $40 is just the beginning; the level of diagnostic capabilities you receive for that price is truly remarkable. We were genuinely surprised by the features packed into such an affordable device.
While there are some trade-offs to be expected at this price, such as the absence of manufacturer-specific codes and a slightly heavier feel, the CR529 still delivers essential features like live data, an instant inspection function, and surprisingly detailed insights into your car’s systems. Furthermore, the inclusion of lifetime updates ensures that this auto scan tool remains useful for years to come, without any subscription fees.
For those seeking a professional-grade auto scan tool, the CR529 might not be the ideal choice. However, for the vast majority of car owners, it’s an excellent option to keep in your toolbox.
Read our in-depth Launch CR529 review
Best Pro-Level Auto Scan Tool
[
(Image credit: Future)
3. Topdon Phoenix Lite 2
Bridging the gap between amateur and professional automotive diagnostics
Read our expert review:
Key Specifications
- Display/Size: Color/8-inch Touchscreen
- Bluetooth/Handheld: Yes/Yes (Wireless with Bluetooth)
- I/M Readiness Test: Yes
- Live Data Display: Yes
- Keys: Touchscreen interface
- Warranty: 2 years
- Size: 10.2 x 7.2 x 1.7 inches
- Weight: 2.6 pounds
Reasons to Buy
- Near-professional OBD scanner capabilities
- Versatile handheld with Wi-Fi and Bluetooth connectivity
- Large 8-inch touchscreen display
- Comprehensive suite of diagnostic tests and live data options
- Includes adapters and a protective hard case
Reasons to Consider
- Bulky and heavy design
- Higher price point
- Subscription required for updates after two years
The Topdon Phoenix Lite 2 is a significant investment compared to many other auto scan tools, but it delivers a wealth of features and capabilities that justify the price for serious car enthusiasts and professional mechanics alike. It effectively blurs the lines between amateur and professional-level diagnostics.
A standout feature is its completely wireless operation. The control pad connects to a Bluetooth receiver plugged into your car’s OBD port, providing unparalleled freedom of movement around the vehicle. While the scanner itself is substantial in size and weight, it features a built-in kickstand and a rugged construction designed to withstand the rigors of a workshop environment.
Beyond basic code reading, the Phoenix Lite 2 offers advanced features like live data graphing, detailed fault information, and a wide array of sophisticated diagnostic functions that surpass the capabilities of most budget-friendly auto scan tools. However, it’s important to note that firmware updates are included for two years, after which an annual subscription of $495 is required.
Explore our full Topdon Phoenix 2 Lite review
Best Dual-Purpose Auto Scan Tool
Ancel BD310 (Image credit: Tom’s Guide)
4. Ancel BD310
A practical OBD-II scanner that doubles as a car performance display
Read our expert review:
Key Specifications
- Display/Size: Color/2 inches
- Bluetooth/Handheld: Yes/Yes
- I/M Readiness Test: Yes
- Live Data Display: Yes
- 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 options
Reasons to Consider
- Minimalist interface design
- Small screen size
The Ancel BD310 is a versatile auto scan tool that offers dual functionality. It operates as a standard handheld scanner and can also connect to your smartphone via Bluetooth. Even more uniquely, it can transform into a secondary display, showing essential engine parameters directly in your car’s cabin.
We found the BD310 to be exceptionally convenient to keep on hand due to its small and lightweight form factor, easily fitting in a glove compartment. While its 2-inch display is somewhat compact, and the four-button interface feels a bit basic, these factors didn’t hinder its diagnostic capabilities.
The included 56-inch cable is ideal for working under the hood, and the BD310 performs key functions like I/M inspection readiness tests and provides performance data including coolant temperature, engine timing, and RPM.
Read our detailed Ancel BD310 review.
Best Auto Scan Tool with Companion App
(Image credit: Carly)
5. Carly OBD-II Scanner
A capable scanner whose value is dependent on your vehicle’s make and model
Read our expert review:
Key Specifications
- Display/Size: None (App-based)
- Bluetooth/Handheld: Yes/No
- I/M Readiness Test: No
- Live Data Display: Yes
- Keys: None (App-based)
- 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
- Covers maintenance and repair functions
- Lifetime warranty and updates
Reasons to Consider
- Feature availability varies by car model
- App subscription can be costly
The Carly OBD Scanner provides a wide array of features, and we were particularly impressed by the quality and functionality of its companion app. While many Bluetooth auto scan tools offer rudimentary apps, Carly’s stands out as one of the best we’ve encountered.
Beyond basic fault code reading and clearing check engine lights, the app offers repair assistance to help you get your car back on the road, and even tools to assess used cars for potential problems before you buy. The lifetime warranty is also a significant and rare benefit.
However, the range of features available is not consistent across all car makes and models. Compatibility is strongest with brands like VW, BMW, and Ford. It’s crucial to verify the compatibility of your specific vehicle before purchasing. Additionally, accessing the full suite of advanced features beyond basic OBD functions requires an ongoing app subscription, which can add to the overall cost.
Explore our complete Carly OBD scanner review
Other Auto Scan Tools We’ve Tested
- Innova CarScan Mobile 1000 (★★★★☆)
The Innova CarScan Mobile 1000 is a highly innovative Bluetooth auto scan tool that inherits Innova’s impressive features, including predictive diagnostics, in a wireless, phone-based format. Its exceptionally simple setup process further enhances its appeal as a Bluetooth-only option.
Read the full Innova CarScan Mobile 1000 review
ThinkCar ThinkDiag TKD01 (★★★★☆)
While larger than many Bluetooth OBD-II adapters, the ThinkCar ThinkDiag TKD01’s size contributes to its robust and nearly indestructible build. Key advantages include extensive manufacturer-specific error codes and advanced fault-code analysis that can resolve minor issues without requiring a mechanic. However, a $40 subscription is necessary after the first year.
Read our full ThinkCar ThinkDiag TKD01 review.
Autel AutoLink AL539 (★★★☆☆)
The Autel AutoLink AL539 auto scan tool is specifically designed for diagnosing electrical problems, incorporating a built-in multimeter. This allows it to identify issues like damaged wiring, short circuits, and blown fuses. It also provides a wide range of live data and the capability to perform pre-inspection readiness checks.
Read our full Autel AutoLink AL539 review
Frequently Asked Questions About Auto Scan Tools
What is an Auto Scan Tool (OBD-II Scanner)?
Ever wondered how mechanics quickly pinpoint car problems? They utilize diagnostic scanners, or auto scan tools, that plug into your car’s OBD port, accessing data from the onboard computer.
At their core, these auto scan tools read and interpret error codes generated by your car when it detects an issue. More advanced models offer real-time system monitoring and even predictive analysis to anticipate potential problems.
What is the OBD-II Port?
The On-Board Diagnostics Version Two (OBD-II) port is a standardized port found in virtually all passenger vehicles sold in the US since 1996, Canada since 1998, the EU since 2004, and Australia, Mexico, and New Zealand since 2006.
This port serves as the interface to your car’s onboard computer. It accommodates various devices, including auto scan tools, insurance tracking devices, and dashcams.
If you’re unsure of your OBD-II port’s location, resources are available to help you find your car’s OBD-II port in North American vehicles or worldwide OBD-II/EOBD port locations.
What is a DTC (Diagnostic Trouble Code)?
DTC stands for Diagnostic Trouble Code, the error code generated by your car’s OBD system when it identifies a problem. These codes are read by auto scan tools, enabling users to diagnose car issues. Many DTCs are standardized across vehicle makes and models, while some manufacturers use proprietary DTCs specific to their vehicles.
Understanding DTC Meanings
DTCs may seem like random letter and number combinations, but they follow a logical structure, providing clues about the nature of the error.
The first letter indicates the affected vehicle system: Powertrain (P), Body (B), Chassis (C), or Network (N). The second character, a number, signifies whether the code is generic (0) or manufacturer-specific (1).
The third character pinpoints the specific system experiencing the issue:
- 1: Fuel and air metering
- 2: Injector circuit (fuel and air metering)
- 3: Ignition system or misfire
- 4: Auxiliary emissions
- 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 further specify the fault, ranging from 0 to 99.
Auto scan tools translate these DTCs into understandable descriptions. Advanced models offer more detailed information. While some online resources like Google can help decipher DTCs, the sheer number of potential codes (over 5,000) can be overwhelming.
It’s important to remember that not all DTCs signal critical problems. While they can indicate major issues, some codes may simply warn of minor anomalies like slightly elevated engine temperature.
Choosing the Best Auto Scan Tool for Your Needs
For gaining insights into your car’s operation and diagnosing problems, an auto scan tool is indispensable. It’s the same technology used by dealerships and repair shops, putting diagnostic power in your hands.
Types of Auto Scan Tools:
- Handheld Auto Scan Tools: These come with an integrated screen and a cable for direct connection to your car’s OBD port.
- Wireless Auto Scan Tools: These plug into the OBD port and connect wirelessly via Bluetooth to a smartphone or tablet for displaying data.
High-quality auto scan tools are available across various price points, with some costing under $200 and basic models even below $30. Key factors to consider when choosing the best auto scan tool include:
- Ease of Setup: A user-friendly setup ensures you’ll readily use the tool when needed.
- Fault Code Explanation: The best auto scan tools not only display fault codes but also provide clear explanations, aiding in DIY repairs or informed communication with mechanics.
- I/M Readiness Check: This feature verifies if your car will pass emissions inspections.
- Accuracy: Reliable results are paramount; inaccurate information is detrimental.
- Size and Weight: A compact and lightweight tool is more likely to be kept in your car for on-the-go diagnostics.
- Live Data: Real-time monitoring of engine parameters can help pinpoint intermittent issues.
- Graphs: Visual data representation enhances data interpretation, especially for comparative analysis.
- Warranty: Opt for tools with warranties that reflect the expected lifespan of your vehicle. Lifetime warranties offer long-term peace of mind.
When selecting an auto scan tool, decide between handheld units with their own displays or wireless models that utilize your smartphone or tablet.
Consider longevity and choose tools with lifetime warranties or software updates to ensure continued compatibility with evolving automotive technology.
For handheld scanners, prioritize screen size and clarity for easy readability. Ruggedized scanners with protective bumpers are beneficial for durability.
Look for extra features like electrical multimeters, manufacturer-specific code reading, or PDF report generation.
The affordability of sophisticated auto scan tools, often under $100, makes them a cost-effective alternative to professional mechanic diagnostic fees.
How We Test Auto Scan Tools
Our auto scan tool testing process involves real-world usage over several weeks using a 2014 Audi A4 Allroad. We verify VIN reporting upon connection to the OBD-II port.
For wireless scanners, we test connectivity with Apple iPads, Microsoft Surface tablets, and Samsung Galaxy smartphones via Bluetooth or Wi-Fi. Handheld scanners are tested via direct OBD-II port connection.
We evaluate cable length on handheld scanners and wireless range on wireless models. Engine and system monitoring is performed with the car running, followed by induced fault conditions, such as disconnecting the engine oil temperature sensor.
We assess the fault code details provided by each scanner, perform repairs, clear check engine lights, and erase error codes.
Road tests are conducted to evaluate live operating data display, including engine speed, timing, and coolant temperature, noting data presentation formats (numeric, graphs, gauges).
We analyze fault code interpretation, understanding the structure of codes with letter prefixes (Powertrain (P), Body (B), Chassis (C), Undefined (U)) and numeric sections indicating generic (starting with 0) or manufacturer-specific (starting with 1) codes.
For example, a P0098 code typically indicates an intake air temperature sensor issue, while a Ford-specific P1112 code suggests intermittent intake air temperature sensor readings requiring sensor replacement.
More from Tom’s Guide
Innova CarScan Mobile 1000 review
ThinkCar ThinkDiag TKD01 review
Autel AutoLink AL539 review
By equipping yourself with the best auto scan tool, you gain the power to understand your car’s health, make informed decisions about maintenance, and potentially save significant costs on auto repairs. Whether you’re a DIY enthusiast or simply a proactive car owner, an auto scan tool is an invaluable asset in today’s automotive landscape.
