Mercedes transmission repair
by Autobahn Performance Inc.
The newer Mercedes 7-speed transmissions (also called G-tronic) used on many 2004 and newer vehicles have the electronic control unit mounted inside the transmission. These control units are failing frequently with speed sensor codes. The codes usually relate to speed sensor faults.
The speed sensors are not replaceable as they are part of the electrical conductor plate that bolts to the valve body inside the bottom of the transmission. The transmission does not need to be removed to replace the valve body or the conductor plate. A valve body comes complete with the conductor plate / control unit. Early valve bodies must be replaced as a complete unit, but later 2nd, or 3rd generation units can be repaired by just replacing the conductor plate / control unit assembly. We have replaced many of these, and have the capability of performing the SCN coding to complete this repair.
These units are failing so often that the dealer has restricted selling them even in their own shop. To order a part, the dealer must submit a request with computer scans and control unit log reports of the suspected failed vehicle’s electronics. The factory then sends the parts they deem necessary for the repair (conductor plate assembly, or complete valve body).