BMW 3: Low-voltage connections
In the low-voltage connector at the Electrical Machine Electronics the following lines and signals are combined:
- Terminal 30 from the hybrid power distribution box
- Terminal 30 from the front left power distribution box
- Terminal 30C (terminal 30 crash signal)
- Ground
- FlexRay bus system
- PT-CAN bus system
- K-CAN 5 bus system
- Input and output of the circuit of the high-voltage interlock loop (EME control unit evaluates the signal and initiates a shutdown of the high-voltage system in the event of an interruption to the circuit. Redundancy of battery management electronics (SME) )
- Actuation of the shutoff valve in the vehicle interior
- Activating the electrical vacuum pump
- Evaluation of the rotor position sensor at the electrical machine
- Evaluation of the temperature sensor at the electrical machine
- Intelligent battery sensor of auxiliary battery (LIN bus).
The Electrical Machine Electronics is connected to the 12 V vehicle electrical system (terminals 30 and 31) via two separate low-voltage connections and lines with large cross-sections. Via this connection the DC/DC converter in the Electrical Machine Electronics provides the entire 12 V vehicle electrical system with energy. These two lines are connected with the Electrical Machine Electronics via a screw connection.
The following graphic summarizes the low-voltage connections of the Electrical Machine Electronics in the form of a simplified wiring diagram:
G20 PHEV, low-voltage connections of the Electrical Machine Electronics
- Electric Motor Electronics (EME)
- Output stage for activating the combined expansion and shutoff valve
- Terminating resistor, FlexRay
- Signal lines of the high-voltage interlock loop
- Electrical machine (entirety)
- Temperature sensor
- Rotor position sensor
- Safety Battery Terminal (SBK)
- 12 V battery
- Intelligent Battery Sensor (IBS)
- Electrical vacuum pump
- Output stage for the activation of the electrical vacuum pump
- Unidirectional DC/DC converter
- Intelligent Battery Sensor (IBS2)
- Additional 12 V battery
- Safety Battery Terminal 2 (SBK2)
- Combined expansion and shutoff valve (interior)
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High-voltage connections
At the Electrical Machine Electronics, there is a total of three high-voltage
connections to connect the
lines for other high-voltage components. The connections for the electric A/C
compressor and
High-voltage cables
The high-voltage cables connect the high-voltage components and are
identified by orange cable
sleeves. The manufacturers of hybrid cars have agreed on a uniform
identification of the high-voltage
c
Removing the flat high-voltage connector
Bridge for high-voltage interlock loop
Before the high-voltage connector can be
disconnected, the bridge for the high-voltage
interlock loop must first be removed. The bridge
closes the circuit
SEE MORE:
Vehicle identification number
Engine compartment
The vehicle identification number can be found
in the engine compartment, on the right-hand
side of the vehicle.
Windshield
The vehicle identification number can also be
found behind the windshield.
iDrive
It is also possible to display the vehicle identification
number via iD
High-voltage power management
The power management for the high-voltage vehicle electrical system includes
two subfunctions: one
for driving and one for charging mode.
In driving mode, the energy flows from the high-voltage battery unit to the
high-voltage consumers
and the energy flows during energy recovery to the high-volt
