R 350 4MATIC (251.165) V6-3.5L (272.967) (2006)
Radiator Cooling Fan: Description and Operation
GF83.40-P-2192RT Engine/AC Electric Suction Fan, Component Description
Component Identification
Location
The suction fan is located behind the radiator.
Task
The suction fan serves for cooling the coolant from the engine and the refrigerant from the air conditioning.
Function
Depending on the refrigerant pressure, and/or the coolant temperature and outside temperature, the speed of the engine and AC electric suction fan with
integrated control is increased continuously.
Actuation of the engine and AC electric suction fan with integrated control is calculated for the front refrigerant circuit by the AAC [KLA] control and
operating unit (N22) or by the comfort AAC [KLA] control and operating unit (N22/7).
The AAC [KLA] control and operating unit or comfort AAC [KLA] control and operating unit sends the information over CAN-B to the EIS [EZS]
control unit (N73) and then over CAN-C to the ME-SFI [ME] control unit (N3/10). The ME-SFI [ME] control unit also receives the current coolant
temperature via the coolant temperature sensor (B11/4) and forwards this information for regulation to the control unit integrated in the engine and AC
electric suction fan with integrated control.
The front SAM control unit (N10) receives the refrigerant pressure from the refrigerant pressure sensor (B12) and the outside temperature from the
outside temperature display temperature sensor (B14).
The input information received by the control unit integrated into the engine and AC electric suction fan with integrated control are compared against
stored values and if necessary the rotational speed of the engine and AC electric suction fan with integrated control is increased to 100 %.
The engine and AC electric suction fan with integrated control runs at 25 % output when the air conditioning systems are switched on for basic
ventilation.
The basic ventilation can be switched off under the following conditions:
^
At an outside temperature <= 15 °C
^
At a ground speed > 70 km/h or 45 mph
Each pressure-dependent speed of the engine and AC electric suction fan with integrated control is retained.