A/C Refrigerant Pressure Sensor
WARNING: This page is about a different car, the 2006 Pontiac Montana SV6, 2006 Chevrolet Uplander, and 2006 Buick Terraza. However, it is still accessible from the selected car via links, so may be relevant.
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 powertrain control module (PCM) or engine control module (ECM) disables the compressor clutch under the following conditions:
- Engine coolant temperature (ECT) is greater than 123°C (253°F).
- A/C high side pressure is more than 2979 kPa (432 psi). The clutch will be enabled after the pressure decreases to less than 1 620 kPa (235 psi).
- A/C low side pressure is less than 179 kPa (26 psi). The clutch will be enabled after the pressure increases to more than 207 kPa (30 psi).