Ambient Temperature Sensor Inspection (Auto A/C)

WARNING: This page is about a different car, the 2017 Mazda 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 [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .)
Remove the front bumper. (See FRONT BUMPER REMOVAL .)
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: Locating Ambient Temperature Sensor Connector
Courtesy of MAZDA MOTORS CORP.
- If the characteristics of the ambient temperature sensor are not as shown in the graph, 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.