Ford F150 Pickup. Instruction — part 1599

TEST. Perform EVAPORATIVE EMISSION REPAIR VERIFICATION DRIVE CYCLE. If both
vacuum gauge readings were not 14-20 in. Hg (47.25-67.54 kPa), check for blockages in the input port
vacuum hose or the EVAP return tube. Check the intake manifold vacuum tree or port for debris. Repair
or install new component(s) as necessary. Perform EVAPORATIVE EMISSIONS SYSTEM LEAK
TEST. Perform EVAPORATIVE EMISSION REPAIR VERIFICATION DRIVE CYCLE.

LS & Thunderbird

1) Check For DTC P0455 Or P1443

If DTC P0455 is present, go to next step. If DTC P0455 is not present, go to step 3).

2) Visually Check For Gross EVAP System Leaks

Check for presence of a fuel filler cap. DO NOT tighten or check for correct installation at this time.
Ensure input port vacuum and EVAP return tube are connected to EVAP canister purge valve. Ensure
canister vent solenoid is properly seated on EVAP canister. Check for damaged fuel tank or fuel filler
pipe. Check for disconnected or cracked fuel vapor hoses or tubes between intake manifold and the
following components:

z

EVAP Canister Purge Valve.

z

EVAP Canister.

z

Fuel Vapor Vent Valve Assembly.

z

Fuel Vapor Control Valve Tube Assembly.

If no concerns are found, go to next step. If a concern was found, repair or replace component as
necessary and go to next step.

3) Check For EVAP System Leaks

Disconnect EVAP return tube from intake manifold and plug EVAP return tube. Connect Evaporative
Emissions System Leak Tester (134-00056) to EVAP test port. EVAP test port is located on EVAP
canister purge valve or on EVAP canister purge outlet tube near EVAP canister purge valve. Perform
EVAPORATIVE EMISSIONS SYSTEM LEAK TEST. If EVAP system pressure stays more than 8
in. H2O (1.99 kPa), go to next step. If EVAP system pressure drops to less than specification, verify fuel
filler cap is installed correctly. Repair or replace as necessary. Perform EVAPORATIVE EMISSIONS
SYSTEM LEAK TEST. When system passes, perform EVAPORATIVE EMISSION REPAIR
VERIFICATION DRIVE CYCLE.

4) Check For Blockage Between EVAP Canister Purge Valve & Canister Vent Solenoid

Turn ignition switch to ON position. Close canister vent solenoid. See CANISTER VENT SOLENOID
CLOSING PROCEDURE. Pressurize EVAP system to 14 in. H2O (3.48 kPa). Open canister vent
solenoid. If pressure drops immediately, go to next step. If pressure does not drop immediately, perform
HISSING SOUND WHEN REMOVING FUEL CAP symptom test under EVAPORATIVE
EMISSION SYSTEM TESTS in SYSTEM & COMPONENT TESTING - GASOLINE article.

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE Self-Diagnostics - CNG, Flex-Fuel & Gasoline

5) Check For Blockage Between Fuel Filler Pipe & Fuel Vapor Control Valve Tube Assembly

Connect evaporative emissions system leak tester to fuel filler pipe. Pressurize EVAP system to 14 in.
H2O (3.48 kPa). If pressure drops immediately, go to next step. If pressure does not drop immediately,
perform HISSING SOUND WHEN REMOVING FUEL CAP symptom test under EVAPORATIVE
EMISSION SYSTEM TESTS in appropriate SYSTEM & COMPONENT TESTING article.

6) Check For Failed EVAP Canister Purge Valve Or Fuel Tank Pressure Sensor

If DTC P0455 and/or P1443 are present, replace EVAP canister purge valve. Perform EVAPORATIVE
EMISSIONS SYSTEM LEAK TEST. If no leak is detected, perform EVAPORATIVE EMISSION
REPAIR VERIFICATION DRIVE CYCLE. If DTCs P0455 and P1443 are not present, replace fuel
tank. Perform EVAPORATIVE EMISSIONS SYSTEM LEAK TEST. When system passes, perform
EVAPORATIVE EMISSION REPAIR VERIFICATION DRIVE CYCLE.

Sable & Taurus

1) Check For DTC P0455 Or P1443

If DTC P0455 is present, go to next step. If DTC P0455 is not present, go to step 3).

2) Check For Gross EVAP System Leaks

Check for presence of a fuel filler cap. DO NOT tighten or check for correct installation at this time.
Ensure input port vacuum and EVAP return tube are connected to EVAP canister purge valve. Ensure
canister vent solenoid is properly seated on EVAP canister. Check for damaged fuel tank or fuel filler
pipe. Check for disconnected or cracked fuel vapor hoses or tubes between intake manifold and the
following components:

z

EVAP Canister Purge Valve

z

EVAP Canister

z

Fuel Vapor Vent Valve Assembly

z

Fuel Vapor Control Valve Tube Assembly (If Equipped)

If no concerns are found, go to next step. If a concern was found, repair or replace component as
necessary and go to next step.

3) Check For EVAP System Leaks

Disconnect EVAP return tube from intake manifold and plug EVAP return tube. Connect Evaporative
Emissions System Leak Tester (134-00056) to EVAP test port. EVAP test port is located on EVAP
canister purge valve or on EVAP canister purge outlet tube near EVAP canister purge valve. Perform
EVAPORATIVE EMISSIONS SYSTEM LEAK TEST. If EVAP system pressure stays more than 8
in. H2O (1.99 kPa), go to next step. If EVAP system pressure drops to less than specification, verify fuel
filler cap is installed correctly. Repair or replace as necessary. Perform EVAPORATIVE EMISSIONS
SYSTEM LEAK TEST. When system passes, perform EVAPORATIVE EMISSION REPAIR
VERIFICATION DRIVE CYCLE.

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE Self-Diagnostics - CNG, Flex-Fuel & Gasoline

4) Check For Blockage Between EVAP Canister Purge Valve & EVAP Canister

Turn ignition switch to ON position. Close canister vent solenoid. See CANISTER VENT SOLENOID
CLOSING PROCEDURE. Pressurize EVAP system to 14 in. H2O (3.48 kPa). Open canister vent
solenoid. If pressure drops immediately, go to next step. If pressure does not drop immediately, replace
vapor line between canister purge valve and EVAP canister. Perform EVAPORATIVE EMISSIONS
SYSTEM LEAK TEST. When system passes, perform EVAPORATIVE EMISSION REPAIR
VERIFICATION DRIVE CYCLE.

5) Check For Blockage Between Fuel Filler Pipe & EVAP Canister

Connect evaporative emissions system leak tester to fuel filler pipe. Pressurize EVAP system to 26-28 in.
H2O (6.47-6.97 kPa). If pressure drops immediately, go to next step. If pressure does not drop
immediately, replace fuel vapor valve tube assembly. Repeat step 5) to verify repair. Perform
EVAPORATIVE EMISSIONS SYSTEM LEAK TEST. When system passes, perform
EVAPORATIVE EMISSION REPAIR VERIFICATION DRIVE CYCLE.

6) Check For Failed EVAP Canister Purge Valve Or Fuel Tank Pressure Sensor

If DTC P0455 and/or P1443 are present, replace EVAP canister purge valve. Perform EVAPORATIVE
EMISSIONS SYSTEM LEAK TEST. If no leak is detected, perform EVAPORATIVE EMISSION
REPAIR VERIFICATION DRIVE CYCLE. If DTCs P0455 and P1443 are not present, replace fuel
tank pressure sensor. Perform EVAPORATIVE EMISSIONS SYSTEM LEAK TEST. When system
passes, perform EVAPORATIVE EMISSION REPAIR VERIFICATION DRIVE CYCLE.

All Others

1) Check For DTC P0455 Or P1443

If DTC P0455 is present, go to next step. If DTC P0455 is not present, go to step 3).

2) Visually Check For Gross EVAP System Leaks

Check for presence of a fuel filler cap. DO NOT tighten or check for correct installation at this time.
Ensure input port vacuum and EVAP return tube are connected to EVAP canister purge valve. Ensure
canister vent solenoid is properly seated on EVAP canister. Check for damaged fuel tank or fuel filler
pipe. Check for disconnected or cracked fuel vapor hoses or tubes between intake manifold and the
following components:

z

EVAP Canister Purge Valve

z

EVAP Canister

z

Fuel Vapor Vent Valve Assembly

z

Fuel Vapor Control Valve Tube Assembly (If Equipped)

If no concerns are found, go to next step. If a concern was found, repair or replace component as
necessary and go to next step.

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE Self-Diagnostics - CNG, Flex-Fuel & Gasoline

3) Check For EVAP System Leaks

Disconnect EVAP return tube from intake manifold and plug EVAP return tube. Connect Evaporative
Emissions System Leak Tester (134-00056) to EVAP test port. EVAP test port is located on EVAP
canister purge valve or on EVAP canister purge outlet tube near EVAP canister purge valve. Perform
EVAPORATIVE EMISSIONS SYSTEM LEAK TEST. If EVAP system pressure stays more than 8
in. H2O (1.99 kPa), go to next step. If EVAP system pressure drops to less than specification, verify fuel
filler cap is installed correctly. Repair or replace as necessary. Perform EVAPORATIVE EMISSIONS
SYSTEM LEAK TEST. When system passes, perform EVAPORATIVE EMISSION REPAIR
VERIFICATION DRIVE CYCLE.

4) Check For Blockage Between EVAP Canister Purge Valve & Fuel Vapor "T" Fitting

Turn ignition switch to ON position. Close canister vent solenoid. See CANISTER VENT SOLENOID
CLOSING PROCEDURE. Pressurize EVAP system to 14 in. H2O (3.48 kPa). Open canister vent
solenoid. If pressure drops immediately, go to next step. If pressure does not drop immediately, replace
vapor line between canister purge valve and fuel vapor "T" fitting. Perform EVAPORATIVE
EMISSIONS SYSTEM LEAK TEST. When system passes, perform EVAPORATIVE EMISSION
REPAIR VERIFICATION DRIVE CYCLE.

5) Check For Blockage Between Fuel Filler Pipe & Fuel Vapor "T" Fitting

Connect evaporative emissions system leak tester to fuel filler pipe. Pressurize EVAP system to 26-28 in.
H2O (6.47-6.97 kPa). If pressure drops immediately, go to next step. If pressure does not drop
immediately, replace fuel tank vapor line(s). Repeat step 5) to verify repair. Perform EVAPORATIVE
EMISSIONS SYSTEM LEAK TEST. When system passes, perform EVAPORATIVE EMISSION
REPAIR VERIFICATION DRIVE CYCLE.

6) Check For Failed EVAP Canister Purge Valve Or Fuel Tank Pressure Sensor

If DTC P0455 and/or P1443 are present, replace EVAP canister purge valve. Perform EVAPORATIVE
EMISSIONS SYSTEM LEAK TEST. If no leak is detected, perform EVAPORATIVE EMISSION
REPAIR VERIFICATION DRIVE CYCLE. If DTCs P0455 and P1443 are not present, replace fuel
tank pressure sensor. Perform EVAPORATIVE EMISSIONS SYSTEM LEAK TEST. When system
passes, perform EVAPORATIVE EMISSION REPAIR VERIFICATION DRIVE CYCLE.

TEST C: DTC P1450: EXCESSIVE VACUUM DETECTED IN FUEL TANK

Diagnostic Aids

Perform this test only when directed by QUICK TEST. DTC P1450 will be set in PCM when EVAP running
loss monitor detects more than -7.2 in. H2O (-1.79 kPa) with engine running (but not at idle) for more than 30

NOTE:

After each service or repair procedure has been completed, reconnect all
components and perform EVAPORATIVE EMISSION REPAIR VERIFICATION
DRIVE CYCLE. Clear DTCs and repeat QUICK TEST procedures to ensure all
EEC-V systems are working properly and DTCs are no longer present.

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE Self-Diagnostics - CNG, Flex-Fuel & Gasoline