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: Hill Launch Assist (HLA)
Hill Launch Assist (HLA) is a function which assists the driver in accelerating
from a stop while on a slope. When the driver releases the brake pedal and depresses
the accelerator pedal while on a slope, the function prevents the vehicle from rolling.
The braking force is maintained automatic ...
Mazda 6 Service Manual: Dtc c1095, c1096
Caution
When attaching the tester lead to the ABS (ABS/TCS) HU/CM harnesses
connector the SST (49 G066 001) must be used. (See ABS (ABS/TCS) HU/CM
INSPECTION.)
Diagnostic procedure
...