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

1. Venting unit
2. Signal connector
3. Connections for refrigerant lines
4. 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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