1. Insert a small screwdriver into the slot and gently pry open the transmitter.

2. Press the portion of the battery indicated by A and remove the battery.

3. Install a new battery (CR2025) into the front portion of the holder with the positive pole (+) facing up. Press on the B portion of the battery to set the battery.
4. Align the front and back covers and snap the transmitter shut.
Battery specification Lithium CR2025 × 1
Note

Door lock timer unit id code change
Transmitter battery 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: Generator inspection
Generator Warning Light
1. Verify that the battery is fully charged.
Charge if necessary.
2. Verify that the drive belt deflection/tension is correct. (See DRIVE BELT
INSPECTION.)
If not as specified, replace the drive belt.
3. Turn the ignition switch to ON and verify that the gene ...