Subaru LEGACY 2002 Quick Reference Index page 516

AUTOMATIC AIR CONDITIONING
HVAC System (Heater, Ventilator and A/C)
B: CABIN TEMPERATURE SENSOR
The cabin temperature sensor sends signals to the ECM.
This sensor consists of an aspirator and a thermistor, the resistance of which changes in inverse
proportion to the temperature. The aspirator uses the vacuum created by the heater unit to direct
cabin air to the thermistor. (The cabin temperature sensor, therefore, functions only while the blow-
er fan is in operation.)
Cabin temperature sensor
B4H1315B
C: AMBIENT TEMPERATURE SENSOR
This sensor uses a thermistor to detect the ambient temperature and sends signals the ECM.
The thermistor can detect only an average temperature of the outside air but cannot respond to
sharp changes in the temperature because its exterior is made of a plastic to increase the thermal
capacity.
The ambient temperature sensor is located on the radiator stay behind the front grille for efficient
exposure to the outside air.
B4H1316A
AC-44