The letter designations of elements on electrical diagrams are as follows:
- A – fuse, device or module holder;
- B – temperature sensor;
- E - lamps;
- F – fuse;
- H – signal (sound or light);
- K – relay;
- M – electric motor;
- N – radio receiver;
- R – potentiometer (resistor);
- S – switch;
- V – valve;
- X – SS or point of "mass";
- Y – outside mirror.
The most important letter designations of terminals on diagrams:
- bus 30 – connected directly to the "+" of the battery, the wires are red or red with stripes;
- bus 31 - connected to ground, brown wires;
- bus 15 – supplies power to consumers via the ignition switch, wires are black or black with colored stripes;
On electrical diagrams, on individual wires, there is a digital and letter designation. The letter designation can consist of two groups of letters separated by a fraction. The first group "GN" is the main color of the wire, the second group "WS" is an additional color of the strip.
Example: 0.5 GN/WS,
- 0.5 – wire cross-section, mm²;
- GN/WS – wire color, green with white stripes.
Wire color decoding
Scheme, in German:
- BL – blue;
- BR – brown;
- GE – yellow;
- GN – green;
- GR – grey;
- RT – red;
- SW – black;
- VI – purple;
- WS – white.
The diagram, in French:
- B - white;
- Bl – blue;
- G – gray;
- J – yellow;
- M - brown;
- N – black;
- R – red;
- Ve – green;
- Violet – purple;
The connectors have their own designation – X254, which indicates that this is a plug connector marked "X254".
In the diagrams, all switches, relays and their contacts are shown in their initial state, with no voltage supplied to them.
Attention! Checking and installation of the vehicle's electrical equipment may only be performed by qualified and specially trained personnel, especially for units with pyrotechnic gas generators of the airbag and the seat belt buckle tensioner.
Any type of work with the NBP units must be carried out only with the battery disconnected, its negative pole (terminal) isolated, and the loop disconnected from the gas generator.
All checks of the electrical part of the airbag system must be carried out only on BMW-DIS equipment.
When removing used airbag elements, use gloves.
