During a gross test, the pump turns on and the console records the pressure (Pon). Then, the pump turns off and two additional pressure readings (P1 and P2) are recorded. If the pressure drops below 12 psi, the gross line test fails, and an alarm will be displayed.
Check for visible leaks – STP sump and under all dispensers. Verify the tank is not out of fuel. An empty tank will prevent a line from properly pressurizing. Check for other alarms on the console. Depending on console programming, other alarms might prevent a manual gross line test from running. Check the line’s pressure