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: Inspection of dtcs for condition detection mode
Note
The cruise set indicator light will illuminate for 3 seconds,
when condition detection mode is on.
If the RESUME/ACCEL switch on the cruise control switch is
malfunctioning, the cruise set indicator light will not give a correct
indication when you inspect the system.
1. Drive ...
Mazda 6 Service Manual: Heater core inspection
1. Remove the A/C unit. (See A/C UNIT REMOVAL/INSTALLATION.)
2. Remove the heater core from the A/C unit.
3. Inspect for cracks, damage, and coolant leakage.
If any problems are found, replace the heater core.
4. Inspect for bent fins.
If any are bent, use a flathead screwdriver to stra ...