Low Refrigerant Message

In the process of controlling the compressor clutch, the heater and A/C programmer monitors certain system inputs for an indication of a low refrigerant charge. If the system's refrigerant state of charge should fall below approximately 1/4 of capacity, the following conditions are present:
^ The VERY LOW A/C REFRIGERANT - COMPRESSOR OFF message displays.
^ The heater and A/C programmer will store DTC B1347 and/or DTC B1348 in memory.