Hero image

Howto – Tech

Mercedes with Sensotronic system:

Many Mercedes with SBC brake system fail. You can said poor design. In my experience its fail due to lack of knowledge from people who have changed brake fluid. In this particular models to do that you need special equipment and follow the procedure from manufacturer workshop. Basically you will need special unit which produce up to 2.5 bar pressure to replace fluid. Also you need computer which have special module designed for Mercedes and know step by step processing.

Audi, Vw post 2008 sequential to connect and disconnect battery :

  • disconnect negative terminal first,
  • disconnect positive battery terminal ( positive should not have contact with bodywork),
  • if you have vehicles with battery monitor control unit – J367- or energy management control unit – J644 separate terminal by unplug from negative terminal first,
  • connect positive terminal,
  • then connect negative terminal and finaly connect plug with monitor control unit.

When you replaced battery for new one, needs to be coded to the car by VCDS to recognize by ECM. Audi group generally is very sensitive to discharged batteries . Very often modules can go to sleep mode due to low voltage from battery.

Mercedes Transmission problem (very common issue)

If your transmission stuck on the gear thats means it is in limp mode.

What you have to do is:

1. Remove key from ignition.

2. Do not press any pedal and buttons.

3. Wait 20 sec  and start the car.

4. If does not go away you need visit garage.

What is causing the problem:

1. Transmission oil to low. Mercedes is very sensitive on that.

2. Wire harness connector. Oil contamination on connectors.

3. Valve body or conductor plate defective on 7G  722.9. Body valve need to be replace or conductor plate and coded to the car.

4. Broken light switch. Easy and chipest option to replace.

5. Shifter module ISM. Electric issue with module, new needs to be programming to TCM.

6. Oil was mixed with coolant due to radiator fail. Valeo brand very often fail.

Meanwhile few useful link to technical website ….

Links to recall campaigns for Mercedes:


Audi newest technology:


Parts diagram for VW, Audi, SEAT, Skoda: