Missing CDi Intake Manifold Actuator/Motor
 

Hi,
I bought my W210 CDi 2.2 two years back, Its working all fine but today it was a great surprise for me when I saw a 3 pin connector near backside of intake manifold. I googled and check it thoroughly and by physical investigation I came to a final conclusion that since from last 2 years I am driving my car without "Intake Manifold Actuator/Motor A6111500494".
This is my first CDi experience, so I am unable to judge the behavior difference between a 2.2 CDi with and without "Intake Manifold Actuator/Motor A6111500494".

Can anyone help me:
1- What is the difference between the behaviour?
2- What benefits I am actually missing (without having the required part)?
3- What could be the reason for which old owner or his mechanic removed this motor?

Thanks!