1. Remove the A/C unit. (See A/C UNIT REMOVAL/INSTALLATION.)
2. Remove the evaporator from the A/C unit.
3. Inspect for cracks, damage, and oil leakage.
4. Inspect for bent fins.
Expansion valve removal/installation
Heater core inspectionMazda 6 Service Manual: Rear oil seal
REAR OIL SEAL REPLACEMENT
1. Remove the flywheel. (MTX) (See CLUTCH UNIT REMOVAL/INSTALLATION)
2. Remove the drive plate. (ATX) (See DRIVE PLATE REMOVAL/INSTALLATION)
3. Remove in the order indicated in the table.
4. Install in the reverse order of removal.
Rear Oil Seal Installation Note
...
Mazda 6 Service Manual: Dtc table
DTCs are common for present and past malfunction diagnosis.
Note
When DTCs not shown in the DTC table are displayed, replace
the SAS unit.
If the air bag system warning light does not illuminate or
remains illuminated when the ignition switch is turned to ON position,
i ...