Outline
The PCM controls energization to the starter relay according to an immobilizer system request to improve security.
While not in P or N position, the starter relay energization by the ignition key is inhibited. (ATX)
While not in neutral, the starter relay energization by the push button start is inhibited. (MTX)
Block Diagram

Operation
The PCM establishes a ground to the starter circuit. Therefore when the ignition is switched to START, the starter relay is energized and the starter motor rotates. As a result, the engine starts normally.
The PCM does not establish a ground to the starter circuit. Therefore, even if the ignition switch is turned to the start position, the starter motor does not rotate because the starter relay does not energize, and the engine does not start.

The PCM turns the starter relay off with the engine speed at the set value or more (value from engine coolant temperature fluctuates).
Refrigerant Charging
Starter Disassembly/Assembly [Skyactiv G 2.0]Add-On Non-Genuine Parts and Accessories
Non-genuine parts and accessories for Mazda vehicles can be found in stores.
These may fit your vehicle, but they are not approved by Mazda for use with Mazda
vehicles. When you install non-genuine parts or accessories, they could affect your
vehicle's performance or safety systems; the Maz ...
Tire Pressure Monitoring System Warning Light
Purpose, Function
The tire pressure monitoring system warning light notifies the driver that
it was determined that a tire pressure has decreased below the specified value
based on the initialization.
The tire pressure monitoring system warning light notifies the driver that
...
Accelerator Pedal, Kickdown Switch [Skyactiv G 2.0]
Purpose, Function
The driver's intentions are transmitted to the PCM via the accelerator pedal.
Kickdown switch (ATX) (Applied VIN (assumed): JM3 KE2*E*D# 148107?)
If the accelerator pedal is depressed carelessly, kickdown control will be
implemented based on the accelera ...