Code P1531, Low A/C Refrigerant Charge: Notes

PCM monitors A/C request signal circuit and completes ground for A/C relay when A/C mode is selected at control head and refrigerant pressure is sufficient to close A/C pressure cycling switch. If refrigerant pressure is low and A/C request signal causes PCM to cycle compressor too often, PCM protects compressor by disabling A/C relay and storing Code P1531.

Code P1531 will set when the following condition is present.

• A/C compressor cycles on 10 or more times within 15 minutes, and compressor on time for each cycle is less than 1.5 seconds.

With Code P1531 set, PCM will not allow compressor operation until next ignition cycle. If Code P1531 is set during 3 ignition cycles, A/C clutch will be disabled until Code P1531 is cleared from memory. P1531 does not illuminate the Malfunction Indicator Light (MIL).