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: Transaxle oil inspection
1. Park the vehicle on level ground.
2. Remove the oil level plug and washer.
3. Verify that the oil is near the brim of the plug port.
If the oil level is lower than the low level, add the specified amount
and type of oil through the oil level plug hole.
Specified oil grade
API Ser ...
Mazda 6 Service Manual: Door lock timer unit inspection
1. Measure the voltage at the door lock timer unit terminals (other than
terminal 1E and 2W) as indicated below.
If not as specified, inspect the parts listed under Action.
2. Disconnect the negative battery cable.
3. Disconnect the door lock timer unit connector and inspect for continuity ...