Guide to Repairing Mercedes-Benz GETRAG VGS2-FDCT TC1784 Transmission with OBDSTAR DC706 on Bench | OBD2 Scanner Blog

Here’s a detailed guide on how to repair the Mercedes-Benz GETRAG VGS2-FDCT TC1784 transmission issue using the OBDSTAR DC706 tool, specifically for models like the A-Class, B-Class, and GLA-Class that may experience difficulty shifting gears due to lost transmission ECU data from a discharged battery. This issue often presents with the diagnostic trouble code (DTC) P051300.

Required Devices and Accessories

OBDSTAR DC706 ECU Tool
OBDSTAR P004 Adapter and ECU Clone Jumper
Main Cable
12V 5A Power Supply (DC)

Operating Mode

In Bench Mode

Step-by-Step Operation Guide

Setup and Connection:

Connect the P004 Adapter to the Benz Transmission Control Module (TCM) using the OBDSTAR P004 ECU Clone Jumper.
Connect this setup to the OBDSTAR DC706 ECU Tool via the main cable.
Attach the 12V 5A power supply to the P004 Adapter.

Software Navigation:

On the DC706 tool, navigate through the menu: ECU Flasher > TCM > TCM V30.27 > vgs2 > BENZ GETRAG VGS2-FDCT TC1784.
Use the ‘Guide’ option to view detailed operation instructions and the wiring diagram.

Wiring Diagram and Connections:

A-Pin 5: 12V (Pin 16 on the tool)
A-Pin 2: GND (Pins 4+5 on the tool)
A-Pin 1: CAN L (Pin 14 on the tool)
A-Pin 3: CAN H (Pin 6 on the tool)

Starting the Repair:

Ensure the OBDSTAR Adapter’s switch is turned on.
Confirm that the DC706 tool is connected to the internet.
Click “Connect” to link up with the ECU. You may need to turn off the ignition and then turn it back on as prompted.
Once connected, begin reading the INT flash and INT eeprom data for the TC1784.

Data Handling:

Save the original data after reading to ensure you have a backup before making changes.

Data Repair:

Select “Repair data” to begin the repair process on the Benz TCM data with the DC706.

Completion:

Once the data repair is completed, verify the functionality to ensure the transmission issues are resolved.