Refrigerant Pressure Sensor / Switch: Testing and Inspection

Before performing diagnosis of the a/c pressure transducer switch, verify that the refrigerant system has the correct refrigerant charge. 1. Turn ON engine and have a/c selected.
2. Using the DRB-III monitor and record the pressure value as it is sent out from the PCM.
3. Connect the high side manifold gauge set to the fitting on the liquid line high side refrigerant system service port.
4. Compare the DRB-III pressure value to the manifold gauge set reading. The pressure reading from the DRB-III should similar to the reading of the manifold gauge set value.
5. If not, replace the a/c pressure transducer.