Safety Systems

Passive Safety Systems and Airbags

One of BMW's traditions is innovation in Passenger Safety systems. Today's BMWs are among the safest cars in the world. Passive Safety is a concept that deals with the protection of the vehicles occupants once a collision is un-avoidable, this is in contrast to Active Safety which assists the driver to avoid a crash (i.e. suspension, ABS/DSC, etc).

The corner stone of passive safety is the vehicle passenger cell or "safety cage". The use of pre-determined crumple zones coupled with the door anchoring system allows the passenger cell to retain a stable shape when the vehicle is involved in an accident.

The use of passenger restraint systems (safety-belts with tensioners) and airbags help to enhance passenger safety by providing the occupants with additional protection during a collision.

Automatic front safety-belt tensioners




This system automatically tightens the front seat-belts in a collision. The tensioners are integrated into the seat belt latch assembly. In some collisions the seat-belt tensioners may be sufficient for passenger restraint so an airbag deployment would be un-necessary.

Airbags
Airbags have been available on BMWs in the US since 1985 equipped in the 1985 E23 L7. The first BMWs with airbags had only a single drivers airbag. Current BMWs may have up to ten airbags. The airbags are triggered by impacts coming from the directions shown in the illustration below.






Front airbags
Impacts from the front may trigger deployment of the front airbags (Driver and Passenger). There are two rates of airbag deployment to ensure that the force of inflation is proportional to the severity of the crash.

Side and Head Protection airbags




In addition to the internal deceleration sensors located inside of the MRS control unit, separate "satellite" or side impact sensors are used to determine collisions from either side. The satellite sensors are located under the two front seats. When the satellite sensors signal a sufficient side impact, the MRS control unit will deploy the front and rear side and head protection airbags.

Rear side airbags come de-activated from the factory. Accident research has shown that the safest place for children is in the rear seat. However, a child sitting in the rear and not properly restrained may position their head too close to the side doors. This could be dangerous if there were to be a side impact and the airbag was to deploy.

The activation of the rear airbags may be requested during the QC I.

Refer to SI: 72 03 99 for instructions on activating and de-activating rear side airbags.

Battery Safety Terminal







The BST is designed to minimize the chance of an under-hood fire by disconnecting the connection between the battery and the starter/alternator circuit. Any time an airbag is deployed the BST is triggered. Once the connection in the BST is interrupted the car will not start, however the interior electronics will still function (i.e locks, windows, lights, etc).

Fuel pump cutoff




As an additional safety feature, the MRS control unit will signal the DME to shut off the fuel pump if an airbag is deployed.

Interior
After a collision the doors are automatically unlocked and the interior lights and four-way flashers are switched on.

Rollover protection system
As part of the passive safety system for convertibles, the RPS system is activated automatically in the event of an accident or when the vehicle is in danger of rolling over. The protective bars located behind the rear seat head restraints, (or inside of the headrest in the case of the E46) extend to provide protection to the occupants by working together with the roll bars integrated into the A-pillars.

Deployment of the roll bars with the convertible top raised or the hardtop installed will not damage the rear window.

The RPS system must be inspected and test deployed every Inspection service or at least every two years. After an accident, inadvertent triggering or an inspection the RPS roll bars can be reset.

E36 RPS reset
To reset RPS in an E36 remove the screw driver handle and special reset tool located in the tool kit. Push the handle and special tool together as shown below.






- Remove the rear headrest.
- Push the special tool into the guide to release the ratchet lock of the mechanism
- Push the roll bar down until the special tool is loose.
- Pull out the special tool and press down the roll bar completely until it engages (audible click is heard).
- Repeat for the second roll bar.

E46 RPS reset






The E46 uses a similar roll bar but requires no special tool for reset. The reset lever is constructed into the roll bar mechanism. Pull the reset lever towards the front of the car and push down on the roll bars until an audible click is heard and the roll bar is secure.

Child Restraint Systems
Automobile accidents remain the number one cause of death and injury to children under 14 years of age. Most recent data estimates (NHTSA traffic safety facts) that Child Restraint Systems when used properly are:
- 71% effective in reducing death for infants.
- 54% effective in reducing toddler deaths.
- 69% in reducing need for hospitalization.

In addition to proper child restraint use:

- Children riding in the rear seat are 37% less likely to be fatally injured

Misuse and compatibility are the two greatest problems facing proper use of Child Restraint Systems. Studies show that 79.5% of child restraints are improperly installed or suited to the child riding in them.

Even when parents are given specific information on their use, more than 50% still make mistakes.

Much of the confusion comes from the large number of Child Restraints that are available in the market at any one time (over 50). Couple this with a variety of vehicle belt systems and it is not so difficult to understand why misuse occurs.

Never install a child safety seat rear-facing in front of an airbag.

For information about Child Safety visit: NHTSA website at www.nhtsa.dot.gov and Safe Kids at www.safekids.org

In an effort to correct vehicle compatibility issues, auto manufacturers are moving to a standardized method of installing a child restraint in a vehicle without using the vehicle belt system. The new system is referred to as the UCSSS (Universal Child Safety Seat System) and is regulated under FMVSS(Federal Motor Vehicle Safety Standard) 225.

The system is designed to greatly simplify child safety seat installation and will protect children by keeping seats more secure in vehicles. The UCSSS will be phased in with all new vehicles and child safety seats by 9/2002.




The UCSSS consists of two lower anchorages and one upper anchor. At least two rear seating positions will be equipped with the system.

The new child safety seats will have a hook or other connector that snaps onto the lower anchor bars in the vehicle. A tether strap from the child seat will be attached to the upper anchor point.

Installation in vehicles before the UCSSS
When installing a rear or forward facing child seat always read the instructions that come with the seat. All of the rear belt retractors and the front passenger's seat belt can be locked for mounting and securing a child seat. Information on its use is printed near the lower anchor of each seat belt.

If the child seat uses an upper tether strap, three anchor points are provided. Depending on the location of the child seat attach the tether strap to the corresponding anchor. If the anchor is behind a headrest pass the tether strap between the headrest and the seat back.

Refer to SI: 72 02 99 for instructions and parts necessary if the vehicle is not currently equipped with anchors.

Typical Sedan and Coupe location




Typical Sport Wagon location