Suburban 1/2 Ton 2WD V8-5.3L VIN T (2004)
Solar Sensor: Description and Operation
SUNLOAD SENSOR ASSEMBLY
The sunload sensor is a 2-wire photo diode. The vehicle uses left and right sunload sensors. The 2 sensors are integrated into the sunload sensor
assembly. Low reference and signal circuits enable the sensor to operate. As the light shining upon the sensor gets brighter, the sensor resistance
increases. The sensor signal decreases as the resistance 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 value. This value will not be
displayed on the scan tool. The default action ensures that the HVAC system can adjust the inside air temperature near the desired temperature until the
condition is fixed. The scan tool parameter for the sunload sensor is the actual state of the signal circuit.
