See also:

Immobilizer System
The immobilizer system allows the engine to start only with a key the system recognizes. If someone attempts to start the engine with an unrecognized key, the engine will not start, thereby helpi ...

Keys
WARNING: Do not leave the key in your vehicle with children and keep them in a place where your children will not find or play with them: Leaving children in a vehicle with the key is dangerous. ...

Under the Hood
Mazda3 models now offer a choice of engines:   Standard  148-horsepower, 2.0-liter four-cylinder engine that teams with a five-speed manual or five-speed automatic transmission Opt ...