DTC P1599: A/C Pressure Sensor Volts Too Low: Description

A/C pressure sensor signal voltage is monitored with engine running and A/C relay energized. DTC will set in Powertrain Control Module (PCM) memory when PCM senses A/C pressure sensor voltage is less than .58 volt for 2.6 seconds. Possible causes are: 5-volt supply circuit open or shorted to ground, defective A/C pressure sensor, signal circuit shorted to ground or sensor ground, or defective PCM.