HVAC Control Components

HVAC CONTROL ASSEMBLY

Air Temperature Description And Operation:

The HVAC control assembly is a non-class 2 device that interfaces between the operator and the HVAC system to maintain air temperature and distribution settings. The ignition 3 voltage circuit provides power to the control assembly. The integrated vacuum system controls the mode door position. The control assembly supports features.

AIR TEMPERATURE CONTROL
The temperature control regulates the HVAC system air temperature in any mode. A temperature control cable mechanically links the temperature control to the temperature door.

A/C REFRIGERANT PRESSURE SENSOR
The A/C refrigerant pressure sensor is a 3 wire piezoelectric pressure transducer. A 5 volt reference, low reference, and signal circuits enable the sensor to operate. The A/C pressure signal can be between 0-5 volts. When the A/C refrigerant pressure is low, the signal value is near 0 volts. When the A/C refrigerant pressure is high, the signal value is near 5 volts.

The A/C refrigerant pressure sensor protects the A/C system from operating when an excessively high or low pressure condition exists. The PCM disables the compressor clutch under the following conditions:

A/C pressure is more than 2979 kPa (432 psi). The clutch will be enabled after the pressure decreases to less than 1510 kPa (219 psi). A/C pressure is less than 186 kPa (27 psi). The clutch will be enabled after the pressure increases to more than 207 kPa (30 psi).