No. 2 Additional Key Programming Procedure (Using the M-MDS): Conditions

WARNING: This page is about a different car, the 2009 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

There is only one valid key, or none.

NOTE:

If a key ID number cannot be programmed and DTC 15 is displayed, the maximum number of programmed keys may have been reached. Verify the number of programmed keys using the M-MDS.
If eight keys have already been programmed and it is necessary to program other keys, the previously programmed key ID numbers must first be cleared.