Mercedes-Benz W202 automatic transmission won't shift or slips
Why does my W202 automatic stay in limp mode and not shift up?
Typical causes are the conductor plate inside the gearbox and its connector, the gear selector, the speed sensor signal and too low a charging voltage. The cause becomes clear from the fault codes; resetting the fault codes or disconnecting the control box does not remove limp mode permanently.
Why does the automatic slip or jerk when oil has leaked?
Oil can rise through the transmission's electrical connector into the control unit and cause a fault. In that case the connector and the seal are replaced and the control unit is cleaned. A wrong oil quantity also prevents normal operation, so the level is checked.
Can the wrong oil make the automatic slip?
Yes. Wrong or old oil can cause slipping, especially when cold. If the oil is still a normal colour, the fault is more likely on the electrical or control side; darkened oil points to a mechanical fault.