Found on the majority of Mercedes vehicles, the 7G-Tronic is the equivalent of the DSG mechatronic for Volkswagen Group vehicles. The 7G-Tronic was first introduced in 2003 on all Mercedes models with 8-cylinders that had a seven-speed gearbox. Because it was lightweight and reliable, the TCU and gearbox were soon added to certain 6-cylinder diesel engines as well. Despite being used as a seven-speed gearbox, the 7G-Tronic in-fact has nine gears - seven driving gears and two reverse. The two reverse gears were introduced to give the car an easier and more comfortable drive when using reverse.
The 7G-Tronic is located on the valve body inside the gearbox, it is likely to encounter prolonged periods of intense heat that can build up within the gearbox. Because of this, it is likely that the TCU could develop various kinds of faults over time, causing the vehicle to suffer from:
These faults could be caused by a series of varying fault codes, which could include:
When sending in the 7G-Tronic we only require the TCU plate and not the (metal) valve body it is attached too. We will always test the TCU on a gearbox set-up to simulate the unit like it is on the vehicle. Testing it first enables us to confirm if we are able to find the reported fault(s) with the unit.
If we do find faults with the TCU, we will conduct a full remanufacture of the unit. We will always follow this with an End of Line (EOL) test which will allow us to approve that the remanufacture has resolved all the reported faults.
It has been known that failures elsewhere on the vehicle can produce the same or similar faults to the 7G-Tronic. We will always suggest technicians to complete full testing before sending any unit to us, which should include – full diagnosis check, checking for broken or corroded wires, faulty sensors or mechanical damage to the gearbox itself. If you believe the 7G-Tronic to faulty, please continue and complete the Remanufacture Order Form.