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: Transmitter
NOTE
(With theft-deterrent system) The hazard warning lights flash
when the theft-deterrent system is armed or turned off. Refer to Theft-Deterrent
System.
(With the advanced keyless function) A beep sound can be heard
for confirmation when the doors are locked/ unlocked using the k ...
Mazda 6 Service Manual: No.9 tcs off light stays on more than 4 seconds with ignition switch on
When performing an asterisked (*) troubleshooting inspection, shake the
wiring harness and connectors while
doing the inspection to discover whether poor contact points are the cause
of any intermittent malfunction. If
there is a problem, check to make sure connectors, terminals and ...