Saving the Original CVN (Calibration Verification Number) in MDG1 ECU
The CVN (Calibration Verification Number) saving function for the MDG1 ECU family is designed to preserve the checksum of the firmware when modifying engine calibrations.
This is especially important for vehicles under warranty — during diagnostic checks, the dealer compares the actual CVN read from the ECU with the CVN stored in the manufacturer’s database.
If the CVNs don’t match, the dealer may deny warranty service due to detected interference in the engine control system.
With this feature, you can safely edit firmware without changing the original CVN.
To operate the module, you need a USB protection key ChipTuningPro. To activate the module, please attach a request file.
How to Fix the Checksum
To fix the checksum (CVN):
- Open the required firmware file without changing any calibrations.
- From the “Commands” menu, select “Fix Checksum (CVN)”.
- In the pop-up window, check the “Fix” box and click “OK”.
After this, you can edit the firmware — its CVN will remain unchanged, ensuring your car passes warranty checks at authorized dealers.
Important Notes Before Purchase
- This function may not work with all MDG1 firmware versions. Please confirm compatibility with technical support before purchasing.
- Only the original CVN from the source firmware is saved. Do not use modified files without the CVN saving mode — such firmware will have an invalid CVN and fail dealer verification.
- If the checksum in the open firmware is missing or incorrect, CVN fixing will not be possible.
1. No Refunds or Modifications for Digital Licenses
Activated modules or licenses cannot be returned or refunded.
If an incorrect key or device number is entered by the customer, the purchase is not eligible for return.
Licenses cannot be modified, transferred, or reissued for another device under any circumstances.
2. Irreversible Order Processing
After the order status changes to “Waiting for activation”, the data has already been sent to the developer.
From this point onward, the order cannot be canceled, edited, corrected, or refunded.
3. Responsibility for Software Functionality
Our store is not responsible for the functionality, performance, or declared features of any software module.
We do not guarantee the listed functions because we are not the developer.
4. Accuracy of Product Information
Module and script descriptions are provided directly by the manufacturer.
IOBD.io is not responsible for any inaccuracies, missing details, or differences between the description and actual operation.
In disputed situations regarding functionality or listed features, the customer must contact the manufacturer.
5. Customer Responsibility for Installation
IOBD.io sells professional automotive diagnostic software and equipment.
Installation, setup, configuration, and compatibility checks must be performed by the customer.
We do not provide remote installation, programming, or setup services unless explicitly stated otherwise.
6. Required Technical Knowledge
These products are intended for users with basic technical knowledge in automotive diagnostics.
The customer is fully responsible for understanding the installation process and using the software and hardware correctly.
7. No Liability for Incorrect Usage
IOBD.IO is not responsible for issues caused by:
incorrect installation
unsupported or incompatible hardware
improper configuration
third-party interference