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: No. 2 all on-board diagnostic functions inoperative
When performing an asterisked (*) troubleshooting inspection, shake the
wiring harness and connectors while doing the inspection to discover whether
poor contact points are the cause of any intermittent malfunctions. If there
is a problem, check to make sure connectors, terminals and wir ...
Mazda 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 ...