The letter designations of the elements on the electrical diagrams are as follows:
- A - fuse holder, device or module;
- 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 - loop or dot «masses»;
- Y - outside mirror.
The most important letter designations of the terminals in the diagrams:
- bus 30 - connected directly to «+» AB, wires are red or red with stripes;
- bus 31 - connected to «weight», brown wires;
- bus 15 - feeds consumers through the ignition switch, black or black wires with colored stripes;
On the electrical diagrams, on individual wires, there is a digital and letter designation. The letter designation can consist of two groups of letters through a fraction. First group «GN» - the main color of the wire, the second group «WS» - additional color of the stripe.
Example: 0.5 GN/WS,
- 0.5 – wire cross-section, mm2;
- GN / WS - wire color, green with white stripes.
Wire color decoding
Scheme, performed in German:
- BL - blue;
- BR - brown;
- GE - yellow;
- GN - green;
- GR - gray;
- RT - red;
- SW - black;
- VI - purple;
- WS - white.
Scheme, performed in French:
- B - white;
- Вl - blue;
- G - gray;
- J - yellow;
- M - brown;
- N - black;
- R - red;
- Ve - green;
- Vi - purple;
The connectors have their own designation - X254, which says that this is a plug connector with the marking «X254».
In the diagrams, all switches, relays and their contacts are shown in their initial state, they are not energized.
Attention! Checking and installation of the vehicle's electrical equipment may only be carried out by qualified and specially trained personnel, especially assemblies with pyrotechnic gas generators for the airbag and the seat belt tensioner.
It is necessary to carry out any kind of work with the airbag units only when the battery is disconnected, its negative pole is isolated (terminal) and disconnected loop from the gas generator.
All checks of the electrical part of the airbag system should be carried out only on the equipment «BMW-DIS».
Wear gloves when removing spent airbag components.