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.

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).