Mercedes-Benz W210 automatic transmission jerks when shifting or kickdown does not work
My W210 automatic jerks or slams when shifting, what can cause it?
Common causes are too little or the wrong transmission oil, in which case changing the oil and filter often helps. In a vacuum-controlled transmission, a leaking vacuum line, a loose hose or a ruptured pressure control diaphragm causes a harsh shift. The shift module connector and the control valve are also suspects.
Why does the W210 automatic kickdown not work?
Kickdown works only when the accelerator pedal is pressed all the way down, and the switch is under the pedal. If the car is in limp mode, for example because of a boost pressure leak or a mass air flow sensor fault, it does not shift normally. In that case the fault is fixed first. The transmission may also need the throttle cable checked.
Does the cable adjustment affect the shift points?
The tension of the cable going to the transmission adjusts the shift points. Tightening makes shifts firmer and moves the shift point to higher revs, loosening softens them. Adjust only a little at a time. If the variation continues, check the vacuum line and the transmission sensors.
The transmission works badly only when warm, what is the cause?
The fault can be in the transmission speed sensor, i.e. the sensor plate, in which case the fault codes show the pressure control valves. The repair involved replacing the sensor plate, the control valve, the connector, the oils and the filter. Finding this out requires reading the fault codes, so take the car to a workshop.