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: Seat warmer switch inspection
1. Remove the seat warmer switch.
2. Inspect for continuity between the seat warmer switch terminals using an
ohmmeter.
If not as specified, replace the seat warmer switch.
Drivers side
Passengers side
...
Mazda 6 Service Manual: High Beam Control System (HBC) (Some models)
The High Beam Control System (HBC) determines the conditions in front of the
vehicle using the Forward Sensing Camera (FSC) while driving in darkness to automatically
switch the headlights between high and low beams.
Refer to Warning/Indicator Lights.
While driving the vehicle at a speed of ab ...