1. Measure the temperature around the water temperature sensor.
2. Measure the resistance between terminals of the water temperature sensor.

Water temperature sensor removal/installation
Refrigerant pressure switch removal/installationMazda 6 Service Manual: Operation
NOTE
The engine may not start and security indicator light may illuminate
or flash if the key is placed in an area where it is difficult for the system
to detect the signal, such as on the dashboard or in the glove compartment.
Move the key to a location within the signal range, switch ...
Mazda 6 Service Manual: i-ELOOP
i-ELOOP is a regenerative braking system. When you depress the brake pedal or
use engine braking, the kinetic energy that occurs is converted to electrical energy
by the power generator and the converted electrical energy is stored in the rechargeable
battery (capacitor and battery). The store ...