1. Introduction
The TOPDON SmartDiag Mini is a compact and powerful Bluetooth OBD2 scanner designed for DIYers and automotive enthusiasts. It allows you to diagnose most vehicle troubles directly from your smartphone or tablet, offering comprehensive system diagnosis and various maintenance services.
1.1. What's in the Box
- 1 x Portable OBD2 Bluetooth Scanner (SmartDiag Mini device)
- 1 x User Manual

Figure 1: The TOPDON SmartDiag Mini OBD2 Scanner device.
2. Setup Guide
Setting up your SmartDiag Mini is a straightforward process that can be completed in minutes. Follow these steps to get started:
2.1. Download the SmartDiag App
The SmartDiag Mini operates exclusively through the dedicated SmartDiag App. Ensure you download the correct application from your device's app store:
- For Android devices (version 5.0.1 and higher): Search for "SmartDiag App" on Google Play Store.
- For iOS devices (version 10.09 and higher): Search for "SmartDiag App" on Apple App Store.
2.2. Connect the SmartDiag Mini to Your Vehicle
Locate your vehicle's OBDII port. This port is typically found under the dashboard, often beneath the steering wheel or in the center console area. Plug the SmartDiag Mini device firmly into the OBDII port.
2.3. Establish Bluetooth Connection (In-App)
Important: Do NOT attempt to pair the SmartDiag Mini via your phone's or tablet's system Bluetooth settings. The Bluetooth connection must be established directly within the SmartDiag App.
- Open the SmartDiag App on your smartphone or tablet.
- Follow the in-app prompts to connect to your SmartDiag Mini device via Bluetooth 4.2. The app will guide you through the pairing process, ensuring a stable and fast signal transmission.
3. Operating Instructions
Once connected, the SmartDiag App provides an intuitive interface for various diagnostic and maintenance functions.
3.1. All System Diagnosis
The SmartDiag Mini offers lifetime free access to all system diagnostics. This includes, but is not limited to, the following vehicle systems:
- Anti-lock Braking System (ABS)
- Supplemental Restraint System (SRS)
- Engine System
- Tire Pressure Monitoring System (TPMS)
- Electronic Parking Brake (EPB)
- Transmission System
Diagnostic data is presented in detailed text and can be viewed in merged graphs for easier analysis. The specific diagnostic menus available will depend on your vehicle's make, model, and year.
Note: This tool does NOT support Active Test functions.
3.2. Common Maintenance Services
The device includes 8 commonly used reset and maintenance services. These services are free for the first year of use. After the first year, a fee of £39.99 will be charged annually for continued access to these functions.
Available services include:
- Steering Angle Sensor (SAS) Reset (supports 44 brands)
- Battery Management System (BMS) Reset (supports 31 brands)
- ABS Bleeding (supports 34 brands)
- Throttle Adaptation (supports 37 brands)
- Oil Reset
- Diesel Particulate Filter (DPF) Regeneration
- Injector Coding
3.3. OBDII Functions
The SmartDiag Mini provides all 10 standard OBDII functions, enabling comprehensive engine diagnostics:
- Read Codes: Displays Diagnostic Trouble Codes (DTCs) and their descriptions.
- Erase Codes: Clears DTCs from the vehicle's computer and turns off the Check Engine Light.
- I/M Readiness: Checks the readiness of the emission monitoring systems.
- Read Data Stream: Displays live data parameters from the vehicle's sensors in real-time.
- View Freeze Frame Data: Shows a snapshot of the vehicle's operating conditions at the time a fault code was set.
- O2 Sensor Test: Retrieves O2 sensor monitor test results.
- On-Board Monitor Test: Retrieves results for emission-related powertrain components and systems.
- EVAP System Test: Initiates a test of the vehicle's Evaporative Emission System.
- Vehicle Information: Retrieves vehicle identification number (VIN), calibration ID (CALID), and calibration verification number (CVN).
- Component Test: Allows testing of specific components or systems.
4. Maintenance
4.1. Device Care
- Keep the SmartDiag Mini clean and dry.
- Avoid extreme temperatures and direct sunlight.
- Store the device in a safe place when not in use to prevent damage.
4.2. Software Updates
Regular software updates are provided through the SmartDiag App to ensure compatibility with new vehicle models and to introduce new features. Ensure your app is always updated to the latest version for optimal performance.
All OBD2 functions and all system diagnostics are free for life. The 8 commonly-used reset/maintenance services are free for the first year. From the second year onwards, a fee of £39.99 will be charged annually for these specific services.
5. Troubleshooting
5.1. Connection Issues
- Device Not Connecting: Ensure the SmartDiag Mini is firmly plugged into the OBDII port. Verify that your vehicle's ignition is on (engine can be off or running, depending on the test).
- Bluetooth Pairing Failure: Remember to establish the Bluetooth connection within the SmartDiag App, not through your device's system settings. If issues persist, try restarting the app and your smartphone/tablet.
- App Crashing/Freezing: Ensure your smartphone/tablet meets the minimum operating system requirements (Android 5.0.1+ / iOS 10.09+). Clear the app's cache or reinstall the app if necessary.
5.2. Diagnostic Data Issues
- No Data/Incorrect Data: Ensure the vehicle's ignition is on. Some functions require the engine to be running. Verify that your vehicle's make, model, and year are correctly selected within the app, as diagnostic menus depend on this information.
- "Not Equipped" Message: If the app indicates a system is "Not Equipped" (e.g., PCM, DTM, Airbags), it means your specific vehicle model does not have that particular module or sensor, or it is not supported by the tool for that vehicle.
5.3. General Issues
- Device Not Powering On: The SmartDiag Mini draws power directly from the OBDII port. Ensure the port is functional.
- Slow Performance: Ensure your smartphone/tablet has sufficient processing power and available memory. Close other background applications.
6. Specifications
| Feature | Detail |
|---|---|
| Brand | TOPDON |
| Model | SmartDiag Mini |
| Power Source | Corded Electric (via OBDII port) |
| Operating System Compatibility | Android 5.0.1 and higher, iOS 10.09 and higher |
| Connectivity | VCI Bluetooth 4.2 |
| Supported OBDII Functions | All 10 OBDII modes |
| Supported Diagnostic Systems | ABS, SRS, Engine, TPMS, EPB, Transmission, and more (all available car systems) |
| Maintenance Services | Oil Reset, SAS, BMS, DPF, ABS Bleeding, Injector Coding, Throttle Adaptation (8 commonly used) |
| Item Weight | 3.2 ounces |
| Package Dimensions | 5.98 x 4.41 x 1.69 inches |
| Language | English |
| Manufacturer Part Number | SmartDiag Mini |
| UPC | 632111336121 |
7. Warranty and Support
7.1. Software Service Fees
All OBD2 functions and all system diagnostics are provided free for the lifetime of the product. The 8 commonly-used reset/maintenance services are free for the first year. From the second year onwards, a fee of £39.99 will be charged annually for these specific services.
7.2. Customer Support
For any questions or assistance, TOPDON offers reliable customer support. You can contact them via message on Facebook by searching for "TOPDON Official" during weekdays.
For additional information or to explore other TOPDON products, visit the TOPDON Store on Amazon.




