No. 3 Key Replacement Procedure (Clearing Previously Registered Key Id Numbers, Key Re-Registration): Procedure

WARNING: This page is about a different car, the 2004 Mazda 3. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Additional Key Registration Method Selection Table

Courtesy of MAZDA MOTORS CORP.

Have two or more keys (key 1, key 2) ready for registration after the clearing the key ID numbers.
Using key 1, turn the ignition switch to the ON position.
NOTE:
- Although the security light flashes and DTC 15 is displayed, this does not indicate an improper procedure. Continue to perform the procedure as indicated.
Connect the WDS or equivalent to the DLC-2.
Select "Body/Security/PATS function" from the WDS or equivalent screen menu.
Perform security access as indicated on the WDS or equivalent screen. (See NO.6 SECURITY ACCESS PROCEDURE .)
Select "Ignition key ID number Erase" from the WDS or equivalent screen menu and perform the tasks according to the WDS or equivalent screen.