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: Rear door lock actuator inspection
Door Lock Actuator
1. Disconnect the front door lock actuator connector.
2. Apply battery positive voltage to the front door lock actuator terminals
and inspect the operation of the front door lock actuator.
If not as specified, replace the front door lock actuator.
With double locking ...
Mazda 6 Service Manual: Fuel tank inspection
Caution
Disconnecting/connecting the quick release connector without
cleaning it may possibly cause damage to the fuel pipe and quick release
connector. Always clean the quick release connector joint area before
disconnecting/connecting using a cloth or soft brush, and make sure that it ...