1. Verify that the joint shaft is not twisted or cracked.
2. Turn the joint shaft by hand and verify that the bearing rotates smoothly and freely.

Drive shaft
Joint shaft removal/installationMazda 6 Service Manual: Automatic Brake Operation Display (Type A Instrument Cluster)
“Smart City Brake Support activated” is indicated in the active driving display,
and “Smart City Brake Support Activated” is indicated in the multi-information display
after the SCBS brakes or the brake assist (SCBS brake assist) is operated.
NOTE
The collision warning beep sounds ...
Mazda 6 Service Manual: Curtain Air Bags
The curtain air bags are mounted in the front and rear window pillars, and the
roof edge along both sides.
When the air bag crash sensors detect a side impact of greater than moderate
force, the curtain air bag inflates quickly and helps to reduce injury mainly to
the rear outboard passenger' ...