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: Mazda Radar Cruise Control (MRCC) (Some models)
The Mazda Radar Cruise Control (MRCC) system is designed to maintain headway
control*1 according to the vehicle speed using a radar sensor (front) to detect
the distance to a vehicle ahead, and by presetting the vehicle speed between 30
km/h (19 mph) and 145 km/h (90 mph), the driver is freed ...
Mazda 6 Service Manual: Setting the System
When the MODE switch is pressed, the Mazda Radar Cruise Control (MRCC) main indication
(white) turns on and the vehicle speed and the distance between vehicles while in
headway control can be set.
NOTE
When the ignition is switched to ACC or OFF while the Mazda Radar Cruise
Control (MR ...