BMW 5 Series: Operating strategy of the heat management module
The following graphic shows the positions of the rotary valve as the coolant
temperature increases.

Circuit diagram of heat management module in B58TU engine
0 % - Rotary valve closed
100% - Rotary valve open
- Cold start
- Warm-up phase
- Operating temperature
- Transition from normal operation to maximum cooling requirement
- Maximum cooling requirement
x - Rotational angle in angular degrees
- Heater circuit
- Main coolant circuit
- Minor coolant circuit
The openings on the rotary valve vary the cross-sections of the different
coolant ducts as a function
of the rotational angle of the rotary valve. The following graphics
schematically represent the various
engine operation phases, from cold start to maximum cooling requirement.
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Point A in the heat management module circuit diagram designates the cold
start with an engine that
has completely cooled down.
Cold-start phase, Bx8TU engine
In the cold-start phase, the coolant c
The positions of the rotary valve at engine operating temperature are shown
by area C of the circuit
diagram.
Operating temperature, Bx8TU engine
The graphic shows control with the engine at operat
The layout and function of the coolant pump have been revised and adapted to
match the cooling
concept of the Bx8 TU engines.
Coolant pump, Bx8TU engine
Pressure relief valve closed (pr
SEE MORE:
Summer tires
Do not drive with a tire tread of less than
0.12 in/3 mm, otherwise there is an increased
risk of hydroplaning.
Winter tires
Do not drive with a tire tread of less than
0.16 in/4 mm, as such tires are less suitable for
winter operation.
Minimum tread depth
Wear indicators are distribut
System wiring diagram
Alarm system
Engine compartment lid contact switch
Fuse for front right power distribution box
Body Domain Controller (BDC)
Door contact, front passenger's side, front
CAN terminator
Door contact on front passenger's side, rear
Fuse for rear right power distribution bo