Codes B446, B447 & B448 Refrigerant System Problem (2 Of 2): Notes

It has been determined from previous chart that problem is not in low refrigerant pressure switch circuit.

NOTE: Test numbers refer to numbers on diagnostic chart.

This is a test to determine if A/C low refrigerant pressure switch opens while compressor is running. If BI08 display remains HI during compressor engagement, then system fault is due to refrigerant.
This checks if switch is opening due to low refrigerant pressure charge or switch is faulty.