Possible causes

– A/C system low or over charged with refrigerant
– Faulty A/C Refrigerant Pressure Sensor
– Cooling fans in-operative
– A/C Refrigerant Pressure Sensor harness is open or shorted
– A/C Refrigerant Pressure Sensor circuit poor electrical connection

Tech notes

There is a service bulletin for the following model:

2001-2003 Buick Rendezvous
Buick Factory Service Bulletin OBDII Code P0530

When is the code detected?

The P0530 code is detected when the signal circuit is less than 5 counts (0.09 volt) or more than 250 counts (4.90 volts) and the condition exists for 20 seconds.

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)
– A/C Inoperative
– A/C Blows Warm

P0530 BUICK Description

The Powertrain Control Module (PCM) monitors the high side refrigerant pressure via a A/C refrigerant pressure sensor. When the pressure is high the signal voltage is high. When the pressure is low the signal voltage is low. When pressure is high the PCM commands the cooling fans on. When pressure is too high or too low the PCM will not allow the A/C compressor clutch to engage.

BUICK Technical Service Bulletins for P0530 code