S320 cdi cooling fan wiring diagram

Hi all,does anyone have a diagram of the cooling fan circuit. My "S" sounds like a jet every time I start the car as the fan is running at 90%.i have checked the engine ecu for faults but none found and engine temp registers normal. The fan stays on whether the ac is on or off. I am an auto electrician by trade so the normal tests have been done. What I have found on the net is that the ecm could be faulty but according to Autodata the fan is controlled by a SAM module. This is where I need assistance to get pinouts and pin voltages and or signals that operates the fan.