No. 3 transmitter id code cannot be reprogrammed
Location indexMazda 6 Service Manual: AUX/USB mode
Audio can be heard from the vehicle's speakers by connecting a commerciallyavailable
portable audio unit to the auxiliary jack.
A commercially-available, non-impedance (3.5 ) stereo mini plug cable is required.
Contact an Authorized Mazda Dealer for details.
In addition, audio can be played fr ...
Mazda 6 Service Manual: Locking, Unlocking the Doors
NOTE
The system may not operate if you are too close to the windows or door
handles.
If the key is left in the following areas and you leave the vehicle,
the doors may be locked depending on the radio wave conditions even if the key
is left in the vehicle.
Around the dashboard
...