7g-tronic box - restricting the shift range - whassit mean?

[Mars]

We have a ML320CDi. It has steering wheel buttons which I assumed were to "tip" the gears up and down but we don't have the M/S button which (the manual says) enables this feature. Instead, the buttons merely restrict the range which...

Mercedes manual said:

...allows ideal acceleration and deceleration. To do this the auto trans will shift down one or more gears.

What I don't get is when I click the buttons, the dash gear selector goes from D to D6, and then D5, D4 etc. What does it all mean?

Bloody manual is useless... no explanation beyond what I've written.

[kilarney]

It just means the gearbox wont go above that figure so in D4 it would use 1,2,3,4 and D1 1st only. Stick it in D1 and see it wont go above 1st gear.

[Mars]

I see, thanks.

Can you provide any reason why it'd be useful? I admit I'm struggling. Having manual-change is obvious. And there's a speed limiter which is a separate system (useful for SPECS zones). I'm obviously missing the point of this one.

Thanks again.

[kilarney]

Its not very usefull tbh. If you wanted to stop the car changing up on light throttle for offroading or towing or spirited driving on A roads.

[jackwood]

Or to use engine braking on decents.

[Mars]

There's a hill descent button to handle that but I suppose it makes sense to restrict it fron changing up on light throttles in some circumstances.

Manual change would have been so much more sensible. Without the S/M button though, we can't trip it into Manual-Change mode. Pity as it's probably just a software update. I would rather they deleted the shift range restrictor and added manual change.


Anyway, thanks for your input, all of you.

[amokwa]

You need to hold the button down you will see the indicator change from D to 3 or 2 depending on your speed release it.

Don't forget to repeat the process with the other button to bump it back to D when required ! I have the C class without the buttons however it works by "tipping" and holding the gear lever.

Edited by amokwa on Tuesday 27th April 12:52

[Mars]

Thanks. If I can prise the keys off Mrs Mars, I'll try it out at the weekend.