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?

C-Class W203/W204

CLS W219

E-Class W211/W212

M-Class W164/W166

S-Class W220/W221

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.