Functional description

Depending on the engine operating range, it is possible to control the flow rate of the individual circuits of the engine cooling circuit connected to the heat management module via the position of the rotary valve. Unlike with a characteristic map thermostat (expansion element), there is no direct physical coupling to the coolant temperature. As a result, the heat management module permits demand-based control of warm-up and cooling of the engine and other ancillary components. The coolant temperature is controlled by the engine control depending on the driving situation and cooling requirement. A position sensor is integrated in the heat management module. The position sensor returns the position (angle) of the rotary valve to the engine control via a SENT signal.

NOTE: The SENT signal was specified by American automobile manufacturers. It is characterized by its simplicity and works on an unshielded three-wire connection which also transmits the supply voltage to the sensors. The transmission via a SENT signal is digital and relatively uncritical against fault signals. That is because the information content is located in the falling signal edge only, whereas the time between two falling signal edges contains the information of the nibbles. The value transmitted by a nibble is proportional to the duration between two falling signal edges.

The heat management module indirectly influences the following functions by the coolant temperature:

Fuel consumption
Power
Factor of quality of the mixture formation
Pollutant emission
Mechanical load on the components

Fig 1: Heat Management Module And Pin Plug Connection
Courtesy of BMW OF NORTH AMERICA, INC.

Item	Explanation
1	Direct current motor with transmission
2	Heat management module
3	five-pin plug connection