BMW 3: Electrical connections
The high-voltage battery unit also has a signal connection, as well as the
high-voltage connection.
The high-voltage battery unit is integrated in the refrigerant circuit in order
for it to be cooled.

Connections of the SP41 high-voltage battery
- Venting unit
- Signal connector
- Connections for refrigerant lines
- High-voltage connection
The electrical lines (high-voltage and signal connection), as well as the
refrigerant lines, can be
disconnected without having to remove the high-voltage battery unit.
Low-voltage connection
There is a signal connection on the left side of the high-voltage battery
unit of the G20 PHEV. The
control units integrated in the high-voltage battery unit are supplied with
voltage, data bus, sensor and
monitoring signals via this interface.
The signal connection has the following lines:
- Voltage supply of the SME control unit with terminal 30 and terminal 31
- Terminal 30C (crash signal) for voltage supply of the electromechanical
switch contactors
- Wake-up line from the Body Domain Controller (BDC)
- Input and output of the signal line for the high-voltage interlock loop
- Output (+12 V and ground) for the actuation of the combined expansion
and shutoff valve as
part of the refrigerant circuit
- K-CAN5.
High-voltage connection
There is a 2-pin flat high-voltage connection at the high-voltage battery
unit with which the high-
voltage battery unit is connected to the EME.
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To increase the service life of the high-voltage battery unit and obtain the
greatest possible power, it
is operated in a defined temperature range. The high-voltage battery unit is
essentially oper
G20 PHEV, system overview of climate control - Installation locations
Combined expansion and shutoff valve at the evaporator
Combined expansion and shutoff valve at the high-voltage battery u
The cooling system has 2 operating conditions, which result from its
function:
Cooling OFF
Cooling ON
Cooling OFF operating condition
The "Cooling OFF" operating condition is active when the cell
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Qualification to work on the high-voltage system of the G20 PHEV (Hybrid
Generation 4.0) can
be acquired via the respective web-based training if the service employee meets
the following
prerequisites:
Performing work on high-voltage components
Valid "High-voltage Components" certification
Concept
The function displays the service requirements
and the corresponding maintenance scopes.
General information
After switching on drive-ready state, the instrument
cluster briefly displays available driving distance
or time to the next scheduled maintenance.
A service advisor can read out the