DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article. Ensure PENDING CODE CHECK &
EVAP MONITOR "BYPASS" CHECK is performed.
20. Testing Fuel Vapor Control Valve Tube & Fuel Tank
Disconnect fuel filler pipe hose at tank and plug hose. Perform evaporative emissions system leak test.
See EVAPORATIVE EMISSIONS SYSTEM LEAK TEST . If system does not pass, go to next step.
If system passes, replace fuel tank assembly. Reconnect all components. Perform evaporative emissions
system leak test. If system passes, perform DRIVE CYCLES in SELF-DIAGNOSTICS - CNG, FLEX-
FUEL & GASOLINE article. Ensure PENDING CODE CHECK & EVAP MONITOR "BYPASS"
CHECK is performed.
21. Testing Fuel Filler Pipe Hose
Disconnect fuel filler pipe hose at fuel filler pipe and plug pipe. Perform evaporative emissions system
leak test. See EVAPORATIVE EMISSIONS SYSTEM LEAK TEST . If system passes, replace fuel
filler pipe hose. Reconnect all components. Perform evaporative emissions system leak test. If system
passes, perform DRIVE CYCLES in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE
article. Ensure PENDING CODE CHECK & EVAP MONITOR "BYPASS" CHECK is performed. If
system did not pass initial test, replace fuel filler pipe assembly. Perform evaporative emissions system
leak test. If system passes, perform DRIVE CYCLES in SELF-DIAGNOSTICS - CNG, FLEX-FUEL &
GASOLINE article. Ensure PENDING CODE CHECK & EVAP MONITOR "BYPASS" CHECK is
performed.
Mustang
1. Evaporative Emission System Leak Test - Perform evaporative emissions system leak test. See
EVAPORATIVE EMISSIONS SYSTEM LEAK TEST . If system passes, go to next step. If system
does not pass, go to step 3 .
2. Testing Evaporative Emission Running Loss System Monitor
Perform DRIVE CYCLES in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article.
Ensure PENDING CODE CHECK & EVAP MONITOR "BYPASS" CHECK is performed. If PCM
DTCs P0442, P0455, P1443 or P1450 are retrieved, see EVAPORATIVE EMISSIONS DIAGNOSTIC
TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE
article for appropriate test procedure. If any other PCM DTCs are retrieved, see DIAGNOSTIC
TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE
article for appropriate test procedure.
3. Testing For Location Of Leak
Connect Evaporative Emissions System Leak Tester (134-00056) to evaporative emissions test port.
Disconnect fuel vapor control valve tube from under vehicle fuel supply and vapor return tube assembly.
Plug both tube open ends. Pressurize system to 14 in. H2O (3.48 kPa). If pressure drops immediately, go
to next step. If pressure does not drop immediately, go to step 9 .
2003 Ford Pickup F150
2003 ENGINE PERFORMANCE System & Component Testing - Gasoline