If PCN is not less than 4 psi, which will generally be the case, the subprogram goes to PRC 14 in the middle of FIG. 5B. If N is less than 64, the pressure is read again and PCN is updated, and if PCN is greater than 20 psi, the pump has probably come back on and the Precision Test and Quick Flags are cleared and the program goes back to the Cat Test.