The side air bags are mounted in the outboard sides of the front seatbacks.
When the air bag crash sensors detect a side impact of greater than moderate force, the system inflates the side air bag only on the side in which the vehicle was hit. The side air bag inflates quickly to reduce injury to the driver or front passenger's chest caused by directly hitting interior parts such as a door or window.
For more details about air bag deployment, refer to "SRS Air Bag Deployment Criteria".
(With Front Passenger Occupant Classification System)
In addition, the front passenger side bag is designed to only deploy when the front passenger occupant classification sensor detects a passenger sitting on the front passenger's seat. For details, refer to the front passenger occupant classification system.

Front Passenger Air Bag
Curtain Air BagsMazda 6 Owners Manual: Side air bag sensor removal/installation
Warning
Handling the side air bag sensor improperly can accidentally
deploy the side air bag module, which may seriously injure you. Read AIR BAG
SYSTEM SERVICE WARNINGS before handling the side air bag sensor. (See
SERVICE WARNINGS.)
1. Turn the ignition switch to LOCK position.
2. ...
Mazda 6 Owners Manual: Wheel hub, steering knuckle pre-inspection
Wheel Bearing Play Inspection
1. Position a dial indicator against the wheel hub.
2. Push and pull the wheel hub by hand in the axial direction and measure the
wheel bearing play.
Maximum wheel bearing play
0.05 mm {0.002 in}
3. If the bearing play exceeds the specification, replace and tig ...