Mazda 3 Sedan 2020 Owner's Manual page 105

Transmitter
1. Transmitter (page 3-5)
Auxiliary key
There is a removable auxiliary key
inside the transmitter.
Removing the auxiliary key
1. Remove the lower cover while
pressing the knob in the direction
of the arrow.
2. Remove the auxiliary key.
Installing the auxiliary key
1. Install the auxiliary key as the
illustration.
2. Insert the tabs of the lower cover
into the slots of the transmitter and
install the lower cover.
Key code number plate
A code number is stamped on the
plate attached to the key set; detach
this plate and store it in a safe place
(not in the vehicle) for use if you need
to make a replacement key (auxiliary
key).
Also write down the code number and
keep it in a separate safe and
convenient place, but not in the
vehicle.
If your key (auxiliary key) is lost, consult
an Authorized Mazda Dealer and have
your code number ready.
1. Key code number plate
Before Driving
Keys
3-3