B0188 GMC - Right Sunload Sensor
Faulty Right Sunload Sensor
Right Sunload Sensor harness is open or shorted
Right Sunload Sensor circuit poor electrical connection
Faulty Heating, Ventilation, and Air Conditioning (HVAC) Control Module
Engine Light ON (or Service Engine Soon Warning Light)
B0188 Gmc Description
The left and right sunload sensors provide the Heating, Ventilation, and Air Conditioning (HVAC) Control Module with inputs as to the amount heat load the sun is placing on the interior of the vehicle. The sunload sensors are photodiodes that are sensitive to light intensity. The Body Control Module (BCM) applies 5 volts to internal input resistors that are connected to the left and right signal circuits of the sunload sensor assembly. The BCM provides ground to the sensors through the low reference circuit. The BCM monitors the voltage drops across the sunload sensors and converts the voltage values to count values where 1 V is approximately equal to 51 counts. As the light intensity increases, the sunload sensors allow more current to travel through the circuits and the signal voltages decrease. As the light intensity decreases, the sunload sensors allow less current to travel through the circuits and the signal voltages increase. The BCM transmits the data to the HVAC control module over the class 2 serial data circuit.