BMW 3: Voltage supply
The 12 V vehicle electrical system of the G20 PHEV is essentially the same as the electrical system of the G20. The main difference lies in the fact that the power supply is no longer by the alternator, but by the high-voltage electrical system. The high voltage of the high-voltage battery unit is converted to the lower voltage (approximately 14 V) using a DC/DC converter in the Electrical Machine Electronics (EME). The electric voltage supply of the 12 V vehicle electrical system is thus no longer dependent on the engine speed of the combustion engine when driving.
Another difference is that the starter motor and auxiliary battery form an independent 12 V vehicle electrical system, which is connected to the standard 12 V vehicle electrical system by the charging unit for the auxiliary battery (Battery Charge Unit (BCU) ).
System overview
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G20 PHEV, system wiring diagram, 12 V voltage supply
- Digital Motor Electronics (DME)
- Integrated supply module (PDM)
- Starter motor
- Power distribution box, engine compartment
- Jump start terminal point
- Electric motor
- Electric Motor Electronics (EME)
- Power distribution box, inner
- Body Domain Controller (BDC)
- Charger unit for auxiliary battery (Battery Charge Unit)
- Hybrid-specific fuse
- Power distribution box, rear
- Hybrid power distribution box
- Safety battery terminal 2 (SBK2)
- Auxiliary battery
- Intelligent battery sensor 2 (IBS2)
- Intelligent Battery Sensor (IBS)
- Battery
- Safety battery terminal (SBK)
- Power distribution box, front left
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Start-up system
Starter motor
The combustion engine B46 can be started via the conventional starter motor
and the electrical
machine.
The following table shows when and under which conditions the respective start
Terminal control for driving readiness
Terminal control from driver's view
Vehicle condition - DRIVING
Vehicle condition - RESIDING
Vehicle condition - PARKING
Transitional condition for establishing driving readiness,
ending driv
Bus Systems
The bus systems of the G20 PHEV are based on the bus systems of the G20. All
the main and sub-bus systems of the G20 are also used in the G20 PHEV. Compared
to the bus systems of the G20,
SEE MORE:
Climate Control
As in previous BMW hybrid vehicles, an electrically powered air conditioning
compressor is used in
the G20 PHEV. Because the A/C compressor has an electric motor, it is possible
to operate the air
conditioning independently of the combustion engine. Thus the customer can enjoy
the cooling ef
Designation and identification
Designation of electrical machines
The electrical machine designation is used in the technical documentation for
clear identification of
the electrical machine. However, the identification of the electrical machine is
relevant for Service.
Identification of the electrical machine
The electrical ma
