Defective speed sensors in the Mercedes 722.8 Autotronic TCM

Which error codes are involved?

There are several error codes that can point in the direction of a faulty speed sensor in the Mercedes-Benz 722.8 Autotronic. The most well-known examples are the following error codes:

    • P0720 - Speed Gradient nPrimGrd > nPrimGrdMax
    • P0722 - The RPM signal from component Y3/9b5 (CVT output rpm sensor) is not available
    • P0793 - Intermediate Shaft Speed Sensor Circuit No Signal
    • P0794 - Intermediate Input Shaft Speed Sensor Signal

In which cars do these error codes occur:

Mercedes-Benz A-Class W169 (2004-2012)

Mercedes-Benz B-Class W245 (2005-2011)

Cause of these error codes

The cause of these malfunctions can be found in the TCU/TCM of the 722.8 transmission. The speed sensors Y3/9B4 and Y3/9B5 (as shown in the image) are controlled by the main circuit board. This means that there is a malfunction in this circuit board, so replacing these sensors does not solve the problem.

Our advice in case of error codes P0720 / P0722 / P0793 / P0794

Do you have a Mercedes-Benz A-Class or B-Class in the workshop with one of these error codes? Then the malfunction can be solved by means of a remanufacture solution from ACtronics! We have developed a remanufacturing method with which we can solve this fault in the printed circuit board. Not only is remanufacturing considerably cheaper than new, but you also get a two-year warranty and there is no need to code the part. Through our almost fully automated process of this part, you will receive it back in your workshop in record time!

Mercedes-Benz Temic (VGS) 722.8 CVT

Do you have any questions about this part and the associated error codes or do you have another related question? Our product specialists are happy to provide you with advice!