Electromagnetic fan drive, function

B20.40-0030-79

10A02 Drive control module (FR)

10A10 Drive control module (CPC)

10A01 Engine control module (MR)

14A01 VOITH retarder control module
Only in vehicles with CODE (B10/ B29 / B30) VOITH R115E/ R120 / R123 retarder

10B08 Coolant temperature sensor

14B02 Retarder oil temperature sensor

10B16 / 10B16A Combined engine oil pressure and temperature sensor

15Y05 Fan solenoid valve (stage 1)

15Y06 Fan solenoid valve (stage 2)

CAN 1 Vehicle's CAN line

CAN 4 Engine's CAN line

Generalities

The fan engages and disengages in function of cooling needs required by the engine and/or retarder. The electromagnetic coupling operates in two stages. In the first stage (with non energized coil) there is no coupling, the fan turns by magnetic drive at a fraction of the engine's pulley and guarantees a minimum cooling of the system.

Operation

The fan coupling is carried out in an electromagnetic way and is controlled by the engine control module MR (10A01). The engine control module MR (10A01) receives information from the coolant temperature sensor (10B08).

These pieces of information are read by the drive control module FR/CPC (10A02/10A10) through the engine CAN line (CAN 4), in retarder fitted vehicles, the retarder oil temperature sensor (14B02) information is included.

The retarder's coolant temperature is transmitted by the retarder's control module (14A01/ 14A02) to the drive control module FR/CPC (10A02/10A10) through the vehicle CAN line (CAN 1).

In case the temperature limit is exceeded and the retarder being actuated at the same time, the drive control module FR/CPC (10A02/10A10) actuates the electromagnetic fan coupling through the engine CAN line (CAN 4).

In the case of coolant temperature sensor failure (10B08) or failure in one of the electromagnetic fan coupling components, a fault indication will be shown to the driver in the instrument cluster display. However, the precondition for this is that there is a current fault.

In the case of coolant temperature sensor failure (10B08) or failure in one of the electromagnetic fan coupling components, the current value of the combined engine oil pressure and temperature sensor (10B16/10B16A) is utilized for the actuation of the electromagnetic fan coupling. In the case of failure of the combined engine oil pressure and temperature sensor (10B16/10B16A), the electromagnetic fan coupling is activated.