For 1990-2009 cars

Bumpers are designed so that the vehicle can withstand a collision into a fixed barrier at 4 km/h (2.5 mph) and sustain minimal damage. At 8 km/h (5.0 mph) additional damage may occur to the bumper impact bar.

After absorbing the energy of the collision, the bumpers return to the original position.

### Fasteners

Aluminum components are used in the vehicles. If the aluminum is not protected by a special finish or an isolator, the aluminum may corrode if the aluminum contacts steel.

Many of the fasteners that are used in the bumper area have one of the following special finishes:

• | GM 6111-M (Gray)

• | GM 6047-M (Black)

The finishes provide adequate protection from corrosion. The special fasteners differ in color from standard metric fasteners. Standard metric fasteners are a medium blue color.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

Do not substitute other fasteners for the GM 6111-M or GM 6047-M special fasteners.

### Anti-Corrosion Protection

Anti-corrosion materials are applied to the surfaces of the metal panels in order to provide rust resistance. If you disturb this material when you are servicing the metal panels, recoat the surfaces with a service-type anti-corrosion material.

### Bumper Energy Absorbing Units

Oldsmobiles are equipped with honeycomb energy absorbing units. Pontiacs and Buicks are equipped with foam energy absorbing units.

Energy absorbers cannot be repaired. Replace the energy absorbers if service is required.