Immobilizer System (without Advanced Key)
If someone attempts to start the engine with an unrecognized key, the engine will not start, thereby helping to prevent the theft of your vehicle.
CAUTION:
Radio equipment like this is governed by laws in the United States. Changes or modifications not expressly approved by the party responsible for compliance could void the user's authority to operate the equipment.
To avoid damage to the key, do not:
Drop the key.
Get the key wet.
Expose the key to any kind of magnetic field.
Expose the key to high
temperatures on places such as the dashboard or hood, under direct sunlight.
When starting the engine do not allow the following, as the engine may not start due to the electronic signal from the ignition key not being transmitted correctly.

A key ring rests on the key grip. 
Metal parts of other keys or metal objects touch the key grip.

Spare keys or keys for other vehicles equipped with an immobilizer system touch or come near the key grip.
Devices for electronic purchases, or
security passage which touch or come near the key.
- (U.S.A.). This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) this device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation. - (CANADA).
This device complies with RSS-210 of Industry CANADA. Operation is subject to the following two conditions: (1) this device may not cause interference, and (2) this device must accept any interference, including interference that may cause undesired operation of the device.
Operation Arming
The system is armed when the ignition switch is turned from the ON to the ACC position.
The security indicator light in the instrument cluster flashes every two seconds until the system is disarmed.
Disarming The system is disarmed when the ignition switch is turned to the ON position with the correct ignition key.The security indicator light illuminates for about three seconds and goes out.
If the engine doesn't start with the correct ignition key, and the security indicator light keeps illuminating or flashing, the system may have a malfunction. Consult an Authorized Mazda Dealer.
NOTE:- If the security indicator light comes on and stays on when the ignition switch is turned to the ON position, the engine will not start. - Signals from a TVor radio station, or from a transceiver or a mobile telephone, could interfere with your immobilizer system. If you are using the proper key and your engine fails to start, check the security indicator light. If it is flashing, remove the ignition key and wait 2 seconds or more, then reinsert it and try starting the engine again. If it doesn't start after 3 or more tries, contact an Authorized Mazda Dealer. - If the security indicator light flashes continuously while you are driving, don't shut off the engine. Go to an Authorized Mazda Dealer and have it checked. If you shut off the engine while the light is flashing you won't be able to restart it.
- Since the electronic codes are reset when repairing the immobilizer system, the keys are needed. Bring all the existing keys to an Authorized Mazda Dealer.
MaintenanceIf you have a problem with the immobilizer system or the key, consult an Authorized Mazda Dealer.
NOTE:- The keys carry a unique electronic code. For this reason, and to assure your safety, obtaining replacement key requires some waiting time. They are only available through an Authorized Mazda Dealer. - Always keep a spare key, in case one is lost. If a key is lost, contact an Authorized Mazda Dealer as soon as possible. - If you lose a key, an Authorized Mazda Dealer will reset the electronic codes of your remaining keys and immobilizer system. Bring all the remaining keys to an Authorized Mazda Dealer to reset.
Starting the vehicle with a key that has not been reset is not possible.
Modification and Add-On EquipmentMazda cannot guarantee the immobilizer system's operation if the system has been modified or if any add-on equipment has been installed to it.
CAUTION:To avoid damage to your vehicle, do not modify the system or install any add-on equipment to the immobilizer system or the vehicle.
Test yourself
A quick Mazda CX-7 quiz: every answer comes with an explanation and a link to the manual page.