Comprehensive Guide to VGS 1, 2, 3 Coding via Vediamo for Mercedes-Benz Transmissions

Before diving into the technical details, it’s important to understand that Mercedes-Benz VGS (Vehicle Gear Shift) units are the transmission control units (TCU) for the 7G-Tronic (722.9) automatic transmissions. These controllers have evolved through three generations—VGS1, VGS2, and VGS3—each with unique programming characteristics. Vediamo software provides advanced capabilities for coding and programming these units, offering functionality beyond what’s available in standard diagnostic tools. This report details the processes, requirements, and capabilities for working with all three VGS generations using Vediamo.

Check: VGS 1, 2, 3 Coding via Vediamo: Expert Manual for Mercedes-Benz Programming

Understanding Vediamo and Its Capabilities

Vediamo is a sophisticated engineering-level software designed for Mercedes-Benz vehicle diagnostics, coding, and programming. Originally developed for Mercedes-Benz engineers to design diagnostic software, it offers capabilities far beyond those available to standard dealer tools. The latest version, Vediamo 5.1.1, supports Mercedes-Benz models up to 2017 and provides enhanced functionality for working with transmission control units4. This software enables technicians to perform specialized operations such as ECU flashing, variant coding, and TCU virginizing that might otherwise require dealer-level equipment.

Unlike consumer-level diagnostic tools, Vediamo provides complete access to ECU parameters, supports batch operations like simultaneously coding multiple ECUs, and allows customization of vehicle-specific programming. It interfaces with the vehicle through various hardware adapters and can interpret and modify complex internal ECU data structures. For VGS coding, Vediamo allows technicians to modify transmission behavior, reset adaptive learning values, and reconfigure transmission control units for installation in different vehicle models4.

Hardware and Software Requirements

Successfully coding VGS units requires specific hardware and software configurations. The baseline software requirement is Vediamo, with versions 04.02.02, 05.00.05, or 5.01.01 mentioned across the source materials. Each version may have different compatibility with hardware interfaces and supported features14.

For hardware connectivity, several options exist:

• Mercedes-Benz Star C3 multiplexer (Chinese version mentioned in tutorials)

• SD Connect C4 interface

• Mercedes-Benz C5 or C6 interfaces

• Open Port 2.0 OBD adapter

• VXDiag interfaces

• Mercedes-Benz Pro M646

Computer system requirements are relatively modest by current standards:

• Windows 10 (64-bit) operating system

• Core i5 processor

• Minimum 4GB RAM

• 5GB SSD storage space

• Recommended models include Panasonic Toughbook series (CF-19, CF-53, CF-54)4

Beyond the basic hardware and software, specific configuration files (CBF files) are required for each TCU type. These files contain the communication protocols and parameters necessary for Vediamo to interface with the specific VGS generation. In many cases, modified or “unlocked” CBF files are necessary to perform advanced coding functions15.

VGS2 “Virginizing” Process

One of the most common procedures for VGS units is “virginizing,” particularly for VGS2 TCUs. This process erases personalization keys from the transmission control unit, allowing it to be reprogrammed and installed in a different vehicle. The procedure is particularly useful when replacing a TCU or when retrofitting a used transmission to a different Mercedes-Benz model1.

The detailed process for virginizing a VGS2 TCU involves the following steps:

1. Copy the modified VGSmod2.cbf file into the Vediamo data directory (typically C:\Documents and Settings\All Users\Application Data\Vediamo\VediamoData)

2. Open Vediamo and select the VGSmod2.cbf file

3. Wait for Vediamo to create a new subdirectory named “VGSmod2”

4. Copy the unpacked VGS2-Virgin.xml script into this newly created subdirectory

5. Establish connection to the TCU

6. Navigate to the “Sequences” section

7. Press “Execute Sequence” (not “OPEN”)

8. Select and start the VGS2-Virgin.xml script

9. Follow the on-screen instructions to complete the process1

It’s worth noting that this process carries some risk. When a TCU is virginized, certain areas of EEPROM memory are erased, which may include the VIN, CALID, shift lever learning values, or SCN (Software Calibration Number). After virginizing, these values need to be reprogrammed when installing the TCU in a different vehicle. Additionally, the software version must match the target vehicle’s VIN and valve body (EHS number), and the coding must match the destination car’s equipment specifications1.

VGS3 Flashing and Coding

VGS3 represents the latest generation of Mercedes 7G-Tronic transmission controllers and requires specific procedures for flashing and coding. According to source5, flashing VGS3 with Vediamo can be challenging without an unlocked CBF file specifically designed for VGS3 programming.

The process for flashing and coding a VGS3 TCU, as demonstrated in the video tutorial, involves:

1. Connecting the TCU using a Mercedes-Benz C4 multiplexer with 120 ohm resistance

2. Opening Vediamo and selecting the appropriate unlocked CBF file

3. Establishing communication with the TCU

4. Checking the stored data to verify the original vehicle application

5. Initiating a reprogramming session by selecting “SCS Su FL” (functional)

6. Loading the programmable flash data from the appropriate CFF file

7. Executing the “Progressive flashing” function to update the TCU firmware

8. After successful flashing, performing variant coding to change the TCU configuration to match the target vehicle

9. Optionally updating the VIN using additional tools (like FV I2 or VIO)5

The tutorial specifically addresses converting a TCU from a C-Class (W204) application to an E-Class (W211) application by changing both the firmware and the variant coding. This indicates that VGS3 units can be repurposed across different vehicle models through proper flashing and coding procedures5.

Variant Coding and Parameter Adjustments

Beyond basic flashing and virginizing, Vediamo provides extensive capabilities for adjusting transmission behavior through variant coding. This allows technicians to modify specific parameters that affect how the transmission functions. While many of these parameters are documented in German within the software, experienced users often save and translate the parameter lists to facilitate coding6.

The variant coding process generally involves:

1. Connecting to the ECU and unlocking it using the appropriate function in Vediamo

2. Navigating to “variant coding” and then “implicit” coding options (avoiding “explicit” options which can cause issues)

3. Modifying specific parameters according to the desired transmission behavior

4. Saving the modified configuration to the TCU6

For TCU-specific coding, the search results indicate that different code strings (like YE9M mentioned in source5) can be used to configure the TCU for specific vehicle applications. The coding determines how the transmission behaves in relation to the vehicle’s engine, weight, and other characteristics.

Backup and Restore Procedures

When performing any coding or programming on VGS units, it’s essential to back up the original configuration. Vediamo provides built-in functionality for backing up both variant coding data and measurement/calibration data7.

To backup variant coding:

1. Click on the appropriate button in the Vediamo interface

2. Choose a filename and folder for saving

3. Confirm to save the variant data7

To backup measurement and calibration data:

1. Click “alle Messwerte lesen” (read all measured values)

2. Click “Speichem in Datei” (save to file)

3. Select the appropriate saving option

4. Confirm to save the data7

These backups provide a safety net, allowing restoration of the original configuration if problems arise after coding or programming. They also serve as reference points for future programming operations on similar vehicles.

Common Issues and Considerations

Working with VGS units via Vediamo presents several challenges and considerations that technicians should be aware of:

1. FBS3 immobilizer system: All VGS generations (1, 2, 3) using the FBS3 immobilizer system will activate and personalize automatically after 300 ignition cycles, even without explicit personalization procedures1.

2. Drive authorization: After flashing or coding a TCU, the drive authorization status should be checked. If it shows as “not activated” or “not personalized,” the unit may still function correctly, but if all values show as dashes, there may be issues with activation on the vehicle5.

3. Software version compatibility: When reusing a TCU on a different Mercedes model, it’s essential to ensure that the software version matches the target vehicle’s specifications. Incorrect software versions may result in refused coding operations or transmission malfunctions1.

4. Seed key requirements: While traditional coding methods often require seed key calculations, some Vediamo functions (particularly in “developer” CBF files) allow unlocking ECUs without seed keys by using the “Grant access” function6.

5. Memory layout restoration: After virginizing a TCU, it’s recommended to reflash the unit to restore its EEPROM layout and update the software to the appropriate version for the target vehicle1.

Conclusion

VGS 1, 2, and 3 coding via Vediamo represents an advanced level of Mercedes-Benz transmission programming that enables technicians to perform operations ranging from basic configuration adjustments to complete TCU repurposing across different vehicle models. The processes differ slightly between generations, with VGS3 generally requiring more specific tools and procedures than earlier generations.

While Vediamo provides powerful capabilities for working with these transmission control units, it also demands a thorough understanding of Mercedes-Benz systems and careful attention to detail. Proper backups, verification of compatibility, and awareness of potential issues are essential for successful VGS coding operations. For technicians with the appropriate knowledge and tools, Vediamo offers a comprehensive solution for diagnosing, coding, and programming all three generations of Mercedes-Benz VGS transmission control units.