BMW 3 Series E30

since 1983-1994 release

Repair and operation of the car

- 1. Maintenance instruction
   1.1.2. Overall dimensions
   1.1.3. Driver's seat
   1.1.4. Dashboard
   1.1.5. Keys for the car equipped with an immobilizer
   1.1.6. Window regulators
   1.1.7. Safety cushions
   1.1.8. On-board computer
   1.1.9. Indexes
   1.1.10. Voltmeter
   1.1.11. Tachometer
   1.1.12. The counter of the total passable way
   1.1.13. Sound signal
   1.1.14. 3-staged automatic transmission
   1.1.15. 4-staged automatic transmission
   1.1.16. Mechanical transmission
   1.1.17. Emergency brake
   1.1.18. Car running in period
   1.1.19. Fuel
   1.1.20. Threefold catalytic converter
   1.1.21. Engine oil
   1.1.22. Brakes
   1.1.23. Rules of placement of freight in a luggage carrier
   1.1.24. Launch of the engine and driving
   1.1.25. Methods of driving
   1.1.26. Towage of the trailer
   1.1.27. Actions at refusal of launch of the engine
   1.1.28. A start order from the additional battery
   1.1.29. If the engine decayed during the movement
   1.1.30. Actions at an engine overheat
   1.1.31. Actions at a wheel puncture
   1.1.32. Rules of towing
   1.1.33. Check of pressure in tires
   1.1.34. Check of a state and replacement of tires
   1.1.35. Shift of wheels
   1.1.36. Installation of winter tires and chains
   1.1.37. Check of an external condition of the battery
   1.1.38. Battery charging
   1.1.39. Specifications
+ 2. Maintenance
+ 3. Engine
+ 4. Cooling system
+ 5. Heating and ventilation
+ 6. Fuel system
+ 7. Exhaust system
+ 8. Transmissions
+ 9. Coupling
+ 10. Brake system
+ 11. Running gear
+ 12. Body
+ 13. Electric equipment
+ 14. Useful tips


1.1.7. Safety cushions


Safety cushion for the driver of the SRS system (additional damping)

The safety cushion of the SRS system is intended for increase in safety of the driver and is an additional tool of damping along with seat belts.

At strong frontal blow the pillow is inflated owing to what provides mitigation of blow along with seat belts and reduces probability of blow of a thorax or driver's head about a steering wheel.

At strong frontal blow the sensor registers braking and causes operation of the inflatable device of a pillow. In the inflatable device there is a chemical reaction as a result of which the pillow is instantly filled with nitrogen (gas is nontoxical), constraining the movement of the driver on inertia. Inflation of a pillow is followed by quite loud sound and release of smoke. These processes harmless also do not mean the fire. As soon as possible wash out the remains of the substances participating in gas emission as perhaps insignificant irritation of skin.

Expansion of a pillow happens for fractions of a second and therefore at inflation the considerable mechanical effort develops. The system is intended for decrease in probability of receiving serious injuries, however application of a pillow in itself can cause insignificant damages of an integument in the form of burns, blisters and grazes.

Within several minutes the nave of a steering wheel can remain is hotter, but the pillow will not heat up. The safety cushion is calculated on single application.

The safety cushion works from a strong frontal push within the shaded area limited to shooters.

Inflation of a safety cushion happens if force of a push exceeds design norm which corresponds to force of collision with motionless absolutely firm wall at a speed of the movement of the car of 20 km/h.

This threshold is obviously exceeded at collision of the car with a barrier which starts moving or is deformed at counter blow (for example with the parked car, or with a road column), or at noncentral blow (blow at which a nasal part of the car as if approaches under an obstacle and in collision does not participate, for example under a truck frame).

The safety cushion does not work at blow behind, side blow or at a car turning, and also at frontal impact at a small speed.


The safety cushion is supportive application and effectively works at use of a seat belt which is the main means for protection at accident. At refusal to use belts vulnerability of the driver at accident sharply increases. For increase in safety the driver and passengers have to be fastened by belts at the movement of the car.

Safety cushions for the driver and the passenger

The safety cushion works even in the absence of the passenger on a front seat.

If force of blow corresponds threshold, then one of two safety cushions provided in the car will work.

The touch device of safety cushions consists of two sensors – the threshold sensor and the sensor of a safety cushion. At strong frontal blow sensors register sharp braking and cause operation of the inflatable device which inflates a pillow with nitrogen.