Mercedes-Benz 722.9 gearbox and error code P0894 / P2502 / P2505 / P2711?
What do these error codes mean?
Before we start explaining the error codes, it is good to emphasize that this article focuses specifically on the Mercedes-Benz 722.9 gearbox. This gearbox was introduced in 2003 for the Mercedes models equipped with an 8-cylinder engine and was produced until 2019. The TCU/TCM, which has the official name ‘ Continental 7G-tronic’, is sensitive to malfunctions. In many cases the error codes point you directly to the TCU, but in some cases it is a bit more difficult. This concerns the following error codes, which mainly seem to point towards a faulty gearbox:
- P0894 - Transmission component slipping
- P2502 - Implausible gear or transmission slipping
- P2505 - Gear not engaged or transmission slipping
- P2711 - Unexpected mechanical gear disengagement
Bij welke Mercedes-Benz modellen komt deze foutcode veel voor?
As mentioned: this problem occurs in many Mercedes-Benz models that are equipped with an 8-cylinder engine.
Causes of Error Codes P0894 / P2502 / P2505 / P2711
These error codes appear as soon as the software detects a problem, often when starting the drive or when shifting gears, but sometimes immediately when starting the engine. Incidentally, the defect can be both a mechanical defect and an electronic defect. And that is precisely what makes a proper diagnosis so difficult.
Our advice in case of error code P0894 / P2502 / P2505 / P2711
However, we have a good tip to make diagnosis much easier: if the fault code P0894, P2502, P2505 or P2711 is diagnosed on its own, it means that there is a mechanical defect in the gearbox. However, if these error codes are read in combination with one or more of the error codes below, this indicates an electronic defect in the gearbox: (In this case, nevertheless, check the gearbox for mechanical problems!)
|Mercedes-Benz 722.9 error codes|
|P0705 - Component Y3/8s1 selection range sensor is defective|
|P0717 - The signal from component (sensor) Y3/8n1 is not available|
|P0718 - Component (sensor) Y3/8n1 is defective|
|P0720 - Output speed sensor circuit malfunction|
|P0721 - The transmission output speed signal is implausible, when compared to the wheel RPM signal|
|P0722 - Output speed sensor no signal|
|P0723 - Output speed sensor is defective|
|P2200 - The signal from component (sensor) Y3/8n2 is not available|
|P2201 - Component (sensor) Y3/8n2 is defective|
|P2204 - The signal from component (sensor) Y3/8n1 is not available|
|P2205 - Component (sensor) Y3/8n1 is defective|
|P2206 - The signal from component (sensor) Y3/8n3 is not available|
|P2207 - The value of component Y3/8n3 is implausible|
|P2550 - Component (sensor) Y3/8n3 is defective|
|P2716 - Pressure control solenoid electrical|
|P2767 - The signal from component (sensor) Y3/8n2 is not available|
|P2768 - Component (sensor) Y3/8n2 is defective|
In this case, the Continental 7G-tronic TCM will have to be remanufactured. Thanks to the latest techniques in the remanufacturing industry, you are assured that your part will return as good as new and can go on the road again for the necessary miles. To prevent transport damage, the 7G-tronic should always be sent in without the hydraulic block. We always return the TCU to you in specially developed transport packaging, because the plastic components of the TCU are particularly fragile. When packing, make sure that the TCU is particularly well protected.