Eletronic throttle control

[Armand Jordaan]

I have a non-GM question to ask...

I have an Electro-mechanically controlled ("ETC" or "drive-by-wire") throttle body (Mannesman VDO part no X22 143 670).
Apparently it is used on the new VW Golf A4.

I can't find any idle air bypass on this throttle body, and wondered if anybody knows if the idle air is controlled by the electric motor only or is a supplemental idle actuator needed to control the idle air opening?

Armand Jordaan