FixVault

Keyless Entry System/Push Button Start System/Immobilizer system

WARNING: This page is about a different car, the 2014 Mazda 3. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Keyless Entry System/Push Button Start System/Immobilizer System Components
G09771896Courtesy of MAZDA MOTORS CORP.