NOTE
Arming
The system is armed when the ignition is switched from ON to off.
The security indicator light in the instrument cluster flashes every 2 seconds until the system is disarmed.

Disarming
The system is disarmed when the ignition is switched ON with the correct programmed key. The security indicator light illuminates for about 3 seconds and then turns off. If the engine does not start with the correct key, and the security indicator light remains illuminated or flashing, try the following:
Make sure the key is within the operational range for signal transmission.
Switch the ignition off, and then restart the engine. If the engine does not start after 3 or more tries, contact an Authorized Mazda Dealer.
NOTE
Make sure to bring all the keys to an Authorized Mazda Dealer so that they can be programmed.
Immobilizer System
Theft-Deterrent System (Some models)Mazda 6 Owners Manual: Door lock timer unit inspection
1. Measure the voltage at the door lock timer unit terminals (other than
terminal 1E and 2W) as indicated below.
If not as specified, inspect the parts listed under Action.
2. Disconnect the negative battery cable.
3. Disconnect the door lock timer unit connector and inspect for continuity ...
Mazda 6 Owners Manual: Sas unit configuration
1. Connect the SST (WDS or equivalent) to the DLC-2.
2. Input vehicle information following the directions on the screen.
3. Select Module programming.
4. Select Programmable module installation.
5. Select the following items and perform procedures according to directions
on the screen.
...