K 1500 Yukon 4WD V8-5.3L VIN Z Flex Fuel (2003)
Low Pressure Sensor / Switch: Description and Operation
HVAC System - Manual
AIR TEMPERATURE
A/C Low Pressure Switch
The A/C low pressure switch protects the A/C system from a low pressure condition that could damage the A/C compressor or cause evaporator icing.
The HVAC control module applies 12 volts to the A/C low pressure switch signal circuit. The switch will open when the A/C low side pressure
reaches 124 kPa (18 psi). This prevents the A/C compressor from operating. The switch will then close when A/C low pressure side reaches 275 kPa
(40 psi). This enables the A/C compressor to turn back ON.