This follows the previous kickdown post.

I think I have a problem with my kickdown switch. (Very serious in a car with an engine this small!)

Car is a 98 C200 5 sp auto. Operating with the box in "S", when I push the throttle past the kickdown switch there is often no down change. I have to push really, really hard to get a down shift.

I think I can almost feel a further switch when I do this, the feeling is like there is a tiny, very stiff micro switch after the kickdown switch. I know there isn't, but that is how it feels.

I know MB gearboxes are loathe to change down, but cruising at 70mph/120kph, you would expect it to kickdown out of top, wouldn't you? When accelerating from this speed using the cruise control, it changes down fine.

I'm not worried if it is broken as the car has a MB warranty and they are very good about these things.

By the way, I'm sure I'm driving in "S"!

ALL trans controls are electronic! The system is adaptive & SHOULD adapt to your style of driving. The fuel computer sends info about DEMAND & allows kickdown.

I'm aware of the adaptive transmission, having used the excellent steptronic ags transmission from BMW, Audi's less effective adaptive transmission and the Porsche tiptronic system (which is adaptive when left in D).

It is certainly the case that if I open the throttle very quickly, the box shifts down, whereas if I roll on the throttle gently, but to the same wide opening, it retains the same gear selection. Similarly, the transmission learns to hold the gears longer after a consistent period of zipping about. It also follows the warm up programme.

What surprised me is how unwilling the box is to change down at motorway speeds. I do drive gently most of the time, but I would expect the transmission to change from 5th to 4th when travelling at 70mph when the accelerator is pushed quickly passed the kickdown switch detent. It doesn't do this. Yet if I really push against the floor, straight leg, back wedged into the seat(!), it eventually downshifts. Is it meant to be this unwilling?

No, it's not. Have it fixed before warranty is up.
Though your description of flooring it (leg tightened and straightened, body pressed agains seat, pushing with all might) is sometimes how I realize I am upon flooring it! And my body instinctively flows (moves forward, then back) with the motion of flooring it! I can hear the CLICK Of kickdown very loudly as I push it so hard. I need to be more gently for fear that I will break it. Oh boy... me without kickdown, I would die!!

You may have a problem with your E/S system. It is possible that the transmission remains in Economic regardless what mode your switch is set on...

Do you experience any difference in accelerating the car when it is in E and in S? Does it start in first gear when you step on the accelerator in S? Is there any difference in shifting up gear when the transmission is switched in either E or S?

...just some thoughts...greetingz,

Thanks for your input MBenz. However, there is no problem with the E/S switch: in "E" the transmission operates on a clearly different programme, starting in second and changing up very quickly. In fact, the transmission is otherwise very good: it shifts smoothly, seems to adapt to driving style, and performs the warm up programme.

I think I'll mention it to the dealer when I get around to having the car serviced. It may be that I am unaccustomed to MB's gentle attitude. However, as I said earlier, I would expect a downshift from 5th when pressing the kickdown button at a crusing speed of 70-80mph (115-130kph), with the transmission in "S". Especially when acceleration from this speed using the crusie control causes a down shift.

It is easy to allow niggling problems to spoil ones enjoyment of a car; in fact I'm very pleased with my car and its overall quality.