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: Traffic Sign Display Indication
The following traffic signs are displayed on the active driving display.
Speed limit signs
Do not enter signs
Stop signs
The above indications are some examples.
NOTE
Speed limit signs
When the vehicle speed is about 1 km/h (0.6 mph) or faster, the speed
limit sign is displayed wh ...
Mazda 6 Service Manual: Cargo compartment light switch inspection
1. Remove the liftgate lower trim. (See LIFTGATE LOWER TRIM
REMOVAL/INSTALLATION)
2. Disconnect the cargo compartment light switch connector.
3. Inspect for continuity between the cargo compartment light switch
terminals using an ohmmeter.
If not as specified, replace the liftgate lock.
...