ELECTRICAL SYSTEM TESTS, INSPECTIONS, AND ADJUSTMENTS - CONTINUED
FUEL FILTER DIFFERENTIAL PRESSURE SWITCH CIRCUIT TEST
System Operation Description:
Perform this procedure if you suspect a problem in circuit for fuel filter differential pressure switch. Perform this
procedure if E390 Fuel Filter Restriction event code is active.
Fuel filter differential pressure switch is used to monitor differential pressure across filter element. Switch is nor-
mally closed. When differential pressure at switch reaches 15 ± 2 psi (103 ± 14 kPa), switch will open. ECM will
alert operator of fuel restriction. Use this test to verify fuel filter differential pressure switch is operating correctly.