A/C Refrigerant Pressure Sensor
A scan tool displays A/C refrigerant pressure in psi. The sensors range and corresponding display should be in the range of 
0 to 
450 psi. A sensor or circuit problem should set DTC P0530. A poor ground at the sensor will result in a fixed high pressure value on the scan tool display. Refer to A/C Compressor Control Circuit Diagnosis.  
Component Tests and General Diagnostics