Transmission Control Modules

The Mercedes 722.6 transmissions are no stranger to problems. One of the common components of the system to fail is actually outside of the transmission and often overlooked until it is too late. If you don't already know, we are talking about the EGS51, or, transmission control module. Often mounted in the module case of the engine bay they commonly fail due to transmission fluid leaking up (yes, we said up) the harness over time and filling the unit and the area that it is mounted. This common issue, and some weird ones, are no problem for us!

We stock most transmission control modules for 722.6 equipped vehicles produced between 1996 and 2000.
  • 129 - SL Class
  • 140 - S Class
  • 163 - ML Class
  • 202 - C Class
  • 208 - CLK Class
  • 210 - E Class
  • 220 - S Class
  • Most vehicles 2001+ are equipped with an EGS52 which we are not servicing at this time.
Prices and availability vary based on the part number.
Contact us for details!


What do I need to do when I install a replacement module?
Newly installed TCM's require a quick learning/adaptation procedure. Instructions are included with each module but it is nearly as simple as installing it and driving it very easy in each gear before regular use.

What else besides the TCM do I need to replace?
Mercedes-Benz will tell you that if you update the control module that you need to also update the valve body & conductor plate which is mounted inside of the transmission. Based on our research and feedback from many shops over the years this is often not the case. Usually if you are updating the TCM/EGS you won't need to update or replace anything else. Some cars will have a delayed shift engagement after updating the TCM. If you experience this then you are one of the unlucky few that will have to also repalce the valve body & conductor plate.

If you first update the valve body & conductor plate then you MUST update the TCM. We only sell the updated or latest TCM for each vehicle.

Can I just use a used unit since these came on so many cars? Aren't they all the same?
No! Using a used TCM/EGS can cause more problems than it solves. While it is true that Mercedes-Benz equipped many of their vehicles with the 722.6 transmission each chassis number has its own set of part numbers and codings that are cruicial for proper operation.

Each unit has a 10-digit Mercedes part number found on a white sticker on the outside of the unit. What you can't see is the 3-digit version code that requires a special diagnostic tool to read. You may get the right part number, but with the wrong version code you may end up with a vehicle that won't go into each gear or is in limp home mode and won't move at all. For example an S-class (sedan) and an SL-class (coupe) can share the same part number of 026 545 72 32 but have different version codes. One has F23, one has F33.

What kind of warranty do you offer?
Our re-manufactured parts come with a 1 year warranty. Please see our policies page for full details.