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: After repair procedure
Caution
After repairing a malfunction, perform this procedure to verify that the
malfunction has been corrected.
When this procedure is carried out, be sure to drive the vehicle at lawful
speed and pay attention to the other vehicles.
1. Connect the WDS or equivalent to the DLC-2.
2. Turn th ...
Mazda 6 Service Manual: No.6 windshield fogged
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 malfunctions. If there
is a problem, check to make sure connectors, terminals and wir ...