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

Cabin temperature sensor removal/installation
Evaporator temperature sensor removal/installationMazda 6 Service Manual: Rear upper arm removal/installation
Caution
Performing the following procedures without first removing the ABS
wheel-speed sensor may possibly cause an open circuit in the harness if it
is pulled by mistake. Before performing the following procedures, remove the
ABS wheel-speed sensor (axle side) and fix it to an appropri ...
Mazda 6 Service Manual: Oil pressure switch inspection
1. Verify that the oil pressure warning light illuminates when the ignition
switch is at ON position.
2. Verify that the oil pressure warning light goes off when the engine is
started.
If the oil pressure warning light does not illuminate or remains
illuminated, inspect the related wirin ...