Aztek AWD V6-3.4L VIN E (2004)
Solar Sensor: Description and Operation
SUNLOAD SENSOR
The sunload sensor is a 2-wire photo diode. Low reference and signal circuits enable the sensor to operate. As the light shining upon the sensor gets
brighter, the sensor conductance increases. The sensor signal decreases as the conductance increases. The sensor operates within an intensity range
between completely dark and bright. The sensor signal varies between 0-5 volts. The HVAC control module converts the signal to a range between
0-255 counts.
The sunload sensor provides the HVAC control module a measurement of the amount of light shining on the vehicle. Bright, or high intensity, light
causes the vehicles inside temperature to increase. The HVAC system compensates for the increased temperature by diverting additional cool air into the
vehicle. If the HVAC control module detects a malfunctioning sensor, then the control module software will use a defaulted sunload valve. The default
action ensures that the HVAC system can adjust the inside air temperature near the desired temperature until the condition is fixed. A resistance check of
the sunload sensor should not be performed as it will damage the sensor.
