Ford F150 Pickup. Instruction — part 1597

cap and EVAP test port for leaks. If a leak is detected, repair or replace components as necessary and go
to next step. If no leak is detected, reinstall fuel filler cap and perform EVAPORATIVE EMISSIONS
SYSTEM LEAK TEST. When system passes, perform EVAPORATIVE EMISSION REPAIR
VERIFICATION DRIVE CYCLE.

5) Check For Concern Other Than Fuel Filler Cap

Refer to previous test results. If EVAP system did not pass EVAPORATIVE EMISSIONS SYSTEM
LEAK TEST performed in step 2), go to next step. If EVAP system passed EVAPORATIVE
EMISSIONS SYSTEM LEAK TEST performed in step 2), repeat EVAPORATIVE EMISSIONS
SYSTEM LEAK TEST. If system now passes leak test, perform EVAPORATIVE EMISSION
REPAIR VERIFICATION DRIVE CYCLE.

6) Check For Small Leak With Tester Set At Fill Position

Connect evaporative emissions system leak tester to EVAP test port. Close canister vent solenoid. See
CANISTER VENT SOLENOID CLOSING PROCEDURE. Set selector on evaporative emissions
system leak tester to FILL position. Pressurize EVAP system to 14 in. H2O (3.48 kPa). If EVAP system
pressure is 13.80-14.20 in. H2O (3.43-3.53 kPa), go to next step. If system does not hold pressure within
specification, release pressure in EVAP system and go to step 8).

7) Check For Leaks In Complete EVAP System

Ensure evaporative emissions system leak tester is connected to EVAP test port. Close canister vent
solenoid. See CANISTER VENT SOLENOID CLOSING PROCEDURE. Pressurize EVAP system to
14 in. H2O (3.48 kPa). While system is under pressure, use ultrasonic leak detector to check the
following EVAP system locations:

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EVAP Return Tube To EVAP Canister Purge Valve

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EVAP Canister Purge Valve To EVAP Canister (Canister Vent Solenoid Assembly)

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EVAP Canister (Canister Vent Solenoid Assembly) To Fuel Tank

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Fuel Filler Cap & Fuel Filler Tube

If no leak is detected at any location, release pressure from EVAP system and go to next step. If leak is
detected at any location, repair or replace component as necessary. Perform EVAPORATIVE
EMISSIONS SYSTEM LEAK TEST. When system passes, perform EVAPORATIVE EMISSION
REPAIR VERIFICATION DRIVE CYCLE.

8) Check For Small Leak Between EVAP Return Tube To EVAP Canister

Disconnect fuel tank vapor tube at fuel vapor "T" fitting. Plug opening in "T" fitting. Connect evaporative
emission system leak tester to EVAP test port. Close canister vent solenoid. See CANISTER VENT
SOLENOID CLOSING PROCEDURE. Pressurize EVAP system to 14 in. H2O (3.48 kPa). While
system is under pressure, use ultrasonic leak detector to check EVAP system from intake manifold to
EVAP canister vent solenoid. If no leak is detected, open canister vent solenoid and go to next step. If
leak is detected, repair or replace component as necessary. Repeat step 6) to verify repair and go to next
step.

2003 Ford Pickup F150

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

9) Check For Small Leak Between EVAP Canister & Fuel Filler Pipe

Connect evaporative emission system leak tester to fuel filler pipe. Transfer plug from fuel vapor "T"
fitting to fuel tank vapor tube. Set selector on evaporative emissions system leak tester to FILL position.
Pressurize EVAP system to 14 in. H2O (3.48 kPa). While system is under pressure, use ultrasonic leak
detector to check fuel tank vapor tube to fuel tank for leaks. Check fuel tank pressure sensor, fuel tank
vapor tube and fuel filler pipe. If no leak is detected, go to next step. If any leak is detected, repair or
replace component as necessary and go to next step.

10) Check EVAP System At Fuel Filler Pipe

Reconnect fuel tank vapor tube to fuel vapor "T" fitting. Perform EVAPORATIVE EMISSIONS
SYSTEM LEAK TEST. If EVAP system passes leak test, restore system to normal operation. Perform
EVAPORATIVE EMISSION REPAIR VERIFICATION DRIVE CYCLE. If EVAP system did not
pass leak test, repeat step 6).

TEST B: DTC P0455: MAJOR LEAK OR NO FLOW DETECTED IN EVAP SYSTEM OR DTC P1443:
VERY SMALL OR NO PURGE FLOW DETECTED IN EVAP SYSTEM

Diagnostic Aids

Perform this test only when directed by QUICK TEST. DTC P0455 will be set in PCM when it senses a -7 in.
H2O (-1.74 kPa) drop over 30 seconds. DTC P1443 will be set in PCM when it senses a -7 in. H2O (-1.74 kPa)
drop over 30 seconds with more than .02 lb. per minute vapor flow.

Focus

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 in EVAP canister. Check for disconnected or cracked fuel vapor
hoses or tubes between intake manifold and the following components:

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EVAP Canister Purge Valve

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EVAP Canister

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Fuel Vapor Vent Valve Assembly

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Fuel Vapor Valve Tube Assembly

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

If no concerns are found, go to next step. If a concern was found, repair or replace component as
necessary and perform EVAPORATIVE EMISSION REPAIR VERIFICATION DRIVE CYCLE.

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 outlet tube near 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, go to step 8).

4) Check For Blockage At EVAP Canister Vent Solenoid Assembly

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 step 6). If pressure does not drop immediately, go to next
step.

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

Disconnect and plug EVAP canister purge outlet tube from EVAP canister. Pressurize system to 14 in.
H2O (3.48 kPa). Remove plug from EVAP canister purge outlet tube. If pressure drops immediately,
perform HISSING SOUND WHEN REMOVING FUEL CAP symptom test under EVAPORATIVE
EMISSION SYSTEM TESTS in appropriate SYSTEM & COMPONENT TESTING article. If pressure
does not drop immediately, remove blockage from EVAP canister purge valve outlet tube. If necessary,
replace EVAP canister purge outlet tube assembly and go to TEST A, step 4).

6) Check For Blockage Between EVAP Test Port & Fuel Tank

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). Remove fuel filler cap.
If pressure drops immediately, go to step 14). If pressure does not drop immediately, go to next step.

7) Check For Blockage Between Fuel Tank & EVAP Canister Tube

Ensure ignition switch is turned to ON position. Connect evaporative emissions system leak tester to fuel
filler pipe. Disconnect and plug EVAP canister tube from fuel tank between EVAP canister purge valve
and EVAP canister. Pressurize system to 26-28 in. H2O (6.47-6.97 kPa). Remove plug from EVAP
canister tube. If pressure drops immediately, replace EVAP canister tube and go to step 14). 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.

8) Check For Large Leak At Fuel Filler Cap

Connect evaporative emissions system leak tester to fuel filler pipe and install fuel cap. Turn ignition
switch to ON position. Close canister vent solenoid. See CANISTER VENT SOLENOID CLOSING

2003 Ford Pickup F150

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

PROCEDURE. Pressurize EVAP system to 14 in. H2O (3.48 kPa). Perform EVAPORATIVE
EMISSIONS SYSTEM LEAK TEST. Using ultrasonic leak detector, check fuel filler cap. If no leak is
detected, go to next step. If leak is detected, replace fuel filler cap and repeat step 8) to verify repair.
When system passes, perform EVAPORATIVE EMISSION REPAIR VERIFICATION DRIVE
CYCLE.

9) Check For Leak At EVAP Canister & Canister Vent Solenoid

Plug canister vent hose assembly. Connect evaporative emissions system leak tester to EVAP test port.
Pressurize system to 14 in. H2O (3.48 kPa). Using ultrasonic leak detector, slowly check EVAP canister
and canister vent solenoid. If no leak is detected, go to next step. If leak is detected, repair or replace
leaking component as necessary. Perform EVAPORATIVE EMISSIONS SYSTEM LEAK TEST.
When system passes, perform EVAPORATIVE EMISSION REPAIR VERIFICATION DRIVE
CYCLE.

10) Check For Leak Between EVAP Test Port & EVAP Canister

Disconnect EVAP canister tube from tube leading to fuel tank and plug EVAP canister side of fitting.
Close canister vent solenoid. See CANISTER VENT SOLENOID CLOSING PROCEDURE. Connect
evaporative emissions system leak tester to EVAP test port. Pressurize EVAP system to 14 in. H2O (3.48
kPa). Using ultrasonic leak detector, slowly check components from EVAP return tube to EVAP canister
tube. If leak is detected, repair or replace fuel vapor hoses or tubes as necessary and go to next step. If no
leak is detected, go to step 12).

11) Check Repairs Between EVAP Test Port & EVAP Canister

Perform EVAPORATIVE EMISSIONS SYSTEM LEAK TEST. If system passes leak test, go to step
14). If system does not pass leak test, go to next step.

12) Check For Leak From Fuel Tank To EVAP Canister Tube

Remove plug installed in step 10) from EVAP canister side of fitting, and install onto fuel tank side of
fitting. Connect evaporative emissions system leak tester to fuel filler pipe. Pressurize system to 26-28 in.
H2O (6.47-6.97 kPa). Using ultrasonic leak detector, slowly check the following components:

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Fuel Filler Pipe

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Fuel Tank

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Fuel Vapor Vent Valve

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Fuel Vapor Control Valve

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Fuel Vapor Control Valve Tube

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Fuel Tank Pressure Sensor

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EVAP Canister Tube

If leak is detected, repair or replace component as necessary and go to next step. If a leak is not detected,
perform EVAPORATIVE EMISSIONS SYSTEM LEAK TEST. If system passes leak test, go to step
14).

2003 Ford Pickup F150

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