If the buttons on the transmitter are inoperable and the operation indicator light does not flash, the battery may be dead.
Replace with a new battery before the transmitter becomes unusable.
CAUTION
The following conditions indicate that the battery power is low:
Replacing the battery at an Authorized Mazda Dealer is recommended to prevent damage to the key. If replacing the battery by yourself, follow the instruction.
Replacing the key battery
1. Press the knob and pull out the auxiliary key.

2. Twist a tape-wrapped flathead screwdriver in the direction of the arrow and open the cover slightly.

3. Insert the tape-wrapped flathead screwdriver into the gap and slide it in the direction of the arrow.

4. Twist the flathead screwdriver in the direction of the arrow and remove the cover.

5. Remove the battery cap, then remove the battery.

6. Insert a new battery with the positive pole facing up, and then cover the battery with the battery cap.

7. Close the cover.

8. Reinsert the auxiliary key.
CAUTION
Be careful not to allow the rubber ring shown in the figure to be scratched or damaged.
If the rubber ring detaches, reattach it before inserting a new battery.

Battery Recharging
TiresMazda 6 Owners Manual: HomeLink Wireless Control System (Some models)
NOTE
HomeLink and HomeLink house icon are registered trademarks of Gentex Corporation.
The HomeLink system replaces up to 3 hand-held transmitters with a single built-in
component in the auto-dimming mirror. Pressing the HomeLink button on the auto-dimming
mirror activates garage doors, gates ...
Mazda 6 Owners Manual: No.8 no cool air
When performing an asterisked (*) troubleshooting inspection, shake the
wiring harness and connectors while performing the inspection to discover
whether poor contact points are the cause of any intermittent malfunctions.
If there is a problem, check to make sure connectors, terminals ...