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: Dtc c1955, c1956
Caution
When attaching the tester lead to the DSC HU/CM connector the SST
(49 G066 004) must be used.
Diagnostic procedure
...
Mazda 6 Owners Manual: Crankshaft position (ckp) sensor inspection
Note
Perform the following inspection only when directed.
Resistance Inspection
1. Disconnect the CKP sensor connector.
2. Measure the resistance between CKP sensor terminals A and B using an
ohmmeter.
If not as specified, replace the CKP sensor.
If CKP sensor resistance is okay, bu ...