1. Introduction and Overview
The OBDSTAR X300M is a professional diagnostic device specifically designed for cluster calibration (odometer adjustment) and OBDII diagnostics. Engineered with an ARM high-speed chip, it ensures stable, fast, and anti-jamming performance. This manual provides essential information for setting up, operating, maintaining, and troubleshooting your X300M device.
Key Features:
- Professional cluster calibration (odometer adjustment)
- Comprehensive car model coverage
- OBDII diagnostic capabilities
- Industrial standard design for portability and shock resistance
- Supports English language only
2. Package Contents and Setup
2.1 What's in the Box
Upon opening your OBDSTAR X300M package, you should find the following items:
- 1 x X300 M main unit
- 1 x Main cable
- 1 x SD card (Host memory card)
- 1 x SD card reader
- 1 x X300M user's manual

2.2 Initial Setup
To begin using your OBDSTAR X300M, ensure the device is fully charged or connected to a stable power source. Connect the main cable to the X300M unit and then to your vehicle's OBD2 socket.
2.3 Software Updates
The device supports software upgrades via a TF card. It is recommended to keep your device updated to ensure compatibility with the latest vehicle models and features. For detailed instructions on how to register and upgrade your device, please refer to the official OBDSTAR website: www.obdstar.com/Service_573.html.

3. Operating Instructions
Follow these steps to perform mileage adjustment using the OBDSTAR X300M:
- Connect the OBDSTAR X300M to your car via the OBD2 socket.
- From the main menu, select VEHICLES.
- Then, select MILEAGE ADJUSTMENT (or CLUSTER CALIBRATE depending on the software version).
- Choose your specific car model. The device will display "initializing..." and then "authorizing...".
- Select the exact car model and year from the displayed options.
- Proceed to ADJUSTMENT.
- The screen will display "communication" as it establishes a connection.
- You will be prompted to enter a filename to save the current mileage data. This is crucial for backup.
- The OBDSTAR X300M will then read the current mileage.
- Input the new desired mileage value.
- The device will display "Adjusting..." followed by "Mileage changes are successful!" once complete.


4. Specifications
| Attribute | Value |
|---|---|
| Brand Name | OBDSTAR |
| Model | X300M |
| Origin | Mainland China |
| Certification | CE |
| Function | Cluster Calibrate |
| Warranty | One Year |
| Processing Time | 1-4 Working Days |
| After Sale Service | Permanent |
| Operation | Easy |
| Support | Many Car Models |
| High-concerned chemical | None |
| Package Length | 31 cm |
| Package Width | 21 cm |
| Package Height | 8 cm |
| Package Weight | 0.9 kg |
5. Troubleshooting
- Device not working on my car / Compatibility issues: The OBDSTAR X300M supports a wide range of vehicles, but not all models are guaranteed. Compatibility can vary by car model, year, and regional specifications. Always contact the seller to obtain the exact vehicle list and confirm compatibility before attempting any operations.
- "Distribution code or other is wrong" during update: If you encounter this message, try using the distributor code
0086A002. - Mileage correction not working for specific models: Some specific car models (e.g., certain BMWs, Peugeot, or Toyota models) may not be fully supported for mileage correction. Refer to the official car list and contact support if issues persist.
- Language display: The device currently supports English language only.
6. User Tips
- Hyundai I20 Mileage Adjustment: For some Hyundai I20 models, users have reported success by inputting four times the desired KM value (e.g., if you need 1000 KM, input 4000 KM into the device).
- Volkswagen Polo 2014 (NEC24C64): When adjusting mileage for a Volkswagen Polo 2014 with NEC24C64, select the "Golf" menu option for successful operation.
- Audi A4 2007: Mileage adjustment for Audi A4 2007 models can be completed quickly, often within 20 seconds, via the OBD port.
- Ignition On: Always ensure the vehicle's ignition is switched on when prompted by the device during the mileage adjustment process.
7. Warranty and Support
The OBDSTAR X300M comes with a One Year Warranty. OBDSTAR provides Permanent After Sale Service to assist with any product-related inquiries or issues.
For technical support, product inquiries, or to confirm vehicle compatibility, please use the following contact information:
- Telephone: 0086 755 86707161
- Email: Leo@obdstar.com
- Skype: obdstar98
- Attention: Leo
You can also visit the official OBDSTAR website for additional resources and support: www.obdstar.com.
8. Important Notes
- Vehicle Compatibility: It is crucial to contact the seller to obtain the exact and most up-to-date vehicle compatibility list before purchasing or attempting any operations. The provided car list is for reference, and actual support may vary.
- Regional Differences: Even for the same car model, there might be differences in compatibility between different countries or regions.
- Mileage Correction Limitations: While the device supports many car models, it cannot guarantee functionality for all vehicles. Some advanced or newer models may not be supported, or may require specific procedures not covered in this general manual.