Motronic & auxiliary air valve

[Jose Santana]

Hello all,
Does anybody Know how the Motronic ECU (BMW M3 E30, 87/88) controls
the auxiliary air valve (used in cold start)? The valve (Bosch, 0 280 140 509) has a 
3  terminals connector. I have made some resistance measures on it  and
they seem to be ok (no short or open circuits). Now, I'd like to check the ECU 
outputs attached to the valve, but I need more info about those 3 outputs.

Any help would be appreciated.
Thanks in advance
Jose Santana <mpower at mx3.redestb.es>
'83     316
'88  ///M3