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: Scheduled Maintenance (U.S.A., Canada, and Puerto Rico)
Follow Schedule 1 if the vehicle is operated mainly where none of the following
conditions (severe driving conditions) apply.
Repeated short-distance driving
Driving in dusty conditions
Driving with extended use of brakes
Driving in areas where salt or other corrosive materials are used
...
Mazda 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 ...