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:
Overview of chassis and suspension in the G30
Front axle spring strut
Auxiliary battery in the engine compartment (optional equipment)
Brake servo
Steering column
Steering wheel
Rear axle spring strut
Five-link rear suspension
Rear axle slip angle control (HSR) (optional equipment)
Electr
The airbag indicator light is located on the instrument panel. The airbag
indicator light lights up and
then goes out during the pre-drive check to signal readiness of the Advanced
Crash Safety Module
(ACSM) and passive safety systems.
G30 Airbag indicator light
Seat belt warning light
A visual a