Radiator Cooling Fan Motor: Description and Operation

TASK
Actuating electric suction-type fan.

DESIGN/FUNCTION
The ME-SFI control module actuates the fan steplessly through the electric suction-type fan (engine/AC) control module. The specified speed of the fan is transmitted by the ME-SFI control module to the electric suction-type fan (engine/AC) control module by means of a pulse width modulated signal. The ON/OFF ratio is 10-90%, the different ratios meaning e.g.

10% electric suction-type fan OFF
20% electric suction-type fan ON, minimum speed
90% electric suction-type fan ON. maximum speed

The status of the A/C or automatic A/C is transmitted by the instrument cluster through the CAN to the ME-SFI control module. The specified speed of the fan is dependent on this status.

NOTE:
CAN-compatible instrument cluster required which is programmed accordingly with HHT to with/without A/C or automatic A/C.

Engine 112 at start of production as of 3/97 viscous fan clutch, fan control phased-in.

Shown On Engine 111:

A1 Instrument cluster
A9 A/C compressor
B11/4 Coolant temperature sensor
L5 Crankshaft position sensor
M4/3 Electric suction,type fan (engine/AC)
N3/10 ME-SFI control module
N19 A/C push button control module
N22 Automatic A/C push button control module
N76 Electric suction-type fan (engine/AC) control module
CAN Data bus (Controller Area Network)