Fan control, function - GF07.61-P-3023M

ENGINES 275.950 in MODEL 215, 220

ENGINES 275.951 in MODEL 230 up to Model Year 08 /Modification Year 07

ENGINES 275.953 in MODEL 216, 221 up to Model Year 08 /modification year 07

ENGINES 275.954 in MODEL 230 up to Model Year 08 /Modification Year 07

ENGINES 275.980 in MODEL 215, 220

ENGINES 275.981 in MODEL 230 up to Model Year 08 /Modification Year 07

ENGINES 275.982 in MODEL 216, 221 up to Model Year 08 /modification year 07

ENGINES 285.950 in MODEL 240

ENGINES 285.980 in MODEL 240

Shown on model 215, 220, 230, 240

Fig 1: Identifying Fan Control Function Diagram

Courtesy of MERCEDES-BENZ USA

The ME-SFI [ME] control unit indirectly actuates the electric suction fan engine and AC with integrated control infinitely. The fan specified speed is transmitted by the ME control unit via a pulse width modulated signal (PWM signal).

The on/off ratio is 10 to 90 %.

Meaning:

10% Electric suction fan OFF

20% Electric suction fan "ON", minimum speed

90% Electric suction fan "ON", maximum speed.

If the actuation is faulty, the electric suction fan rotates with maximum rotational speed (fan emergency mode).

The status of the automatic air conditioning is transmitted from the instrument cluster via the CAN databus to the ME-SFI control unit. The fan specified speed is dependent on this information and on the coolant temperature.

The suction fan continues running for up to 5 minutes after ignition "OFF" if the coolant temperature, the engine oil temperature or the temperature of the ME control unit exceeds specified maximum values.

If the battery voltage drops excessively during this operation, suction fan run-on is suppressed.

Model 230, 240

If case of SBC undervoltage, the fan speed is limited and a fault code is stored in the ME control unit.

ME-SFI control unit, location/task/design/ function	GF07.61-P-5000M
Crankshaft position sensor, location/task/ design/function	GF07.04-P-4116M
Coolant temperature sensor, location/task/ design/function	GF07.04-P-5026M