Ambient Temperature Sensor Inspection (Auto A/C)

WARNING: This page is about a different car, the 2016 Mazda CX-3. However, it is still accessible from the selected car via links, so may be relevant.

Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION .)
Remove the front bumper. (See FRONT BUMPER REMOVAL .) (See FRONT BUMPER INSTALLATION .)
Remove the ambient temperature sensor. (See AMBIENT TEMPERATURE SENSOR REMOVAL/INSTALLATION (AUTO A/C) .)
Measure the temperature around the ambient temperature sensor and measure the resistance between the ambient temperature sensor terminals A and B.

Fig 1: Identifying Ambient Temperature Sensor Connector Terminals
Courtesy of MAZDA MOTORS CORP.
- If the characteristics of the ambient temperature sensor are not as shown in the figure, replace the ambient temperature sensor. (See AMBIENT TEMPERATURE SENSOR REMOVAL/INSTALLATION (AUTO A/C) .)

Fig 2: Ambient Temperature Sensor Resistance Graph

Courtesy of MAZDA MOTORS CORP.