Ford F150 Pickup. Manual — part 1595

and fuel vapor vent valve for cuts or loose connections. Check fuel filler pipe for damage. If no concerns
were found, go to next step. If concern was found, repair or replace component as necessary and go to
next step.

2) Check EVAP Test Port For Small System Leaks

Disconnect and plug EVAP emission return tube at intake manifold. Perform EVAPORATIVE
EMISSIONS SYSTEM LEAK TEST. If EVAP system does not pass leak test, go to step 4). If system
passes leak test, go to next step.

3) Visually Inspect Fuel Filler Cap

Visually inspect fuel filler cap for damage. If fuel filler cap is okay, go to next step. If fuel filler cap is
damaged, replace fuel filler cap and go to next step.

4) Check For Small Leaks At Fuel Filler Cap & EVAP Test Port

Connect Evaporative Emissions System Leak Tester (134-00056) to fuel filler pipe. 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 fuel filler
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:

2003 Ford Pickup F150

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

z

EVAP Return Tube To EVAP Canister Purge Valve

z

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

z

EVAP Canister (Canister Vent Solenoid Assembly) To Fuel Tank

z

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 a 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 Fuel Vapor "T" Fitting

Disconnect EVAP canister purge outlet tube at fuel vapor "T" fitting. Plug opening in EVAP canister
purge outlet tube. Connect evaporative emission system leak tester to EVAP test port. 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 purge outlet tube. If no leak is detected, 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.

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

Connect evaporative emission system leak tester to fuel filler pipe. Transfer plug from EVAP canister
purge outlet tube to fuel vapor "T" fitting. Set selector on evaporative emissions system leak tester to
FILL position. 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 fuel vapor control valve tube to fuel tank for leaks. Check fuel tank
pressure sensor, fuel vapor control valve tube and fuel filler pipe. Check fuel tank to EVAP canister
(canister vent solenoid). 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 EVAP canister purge outlet tube to fuel vapor "T" fitting. Perform EVAPORATIVE
EMISSIONS SYSTEM LEAK TEST. If EVAP system passes leak test, perform EVAPORATIVE
EMISSION REPAIR VERIFICATION DRIVE CYCLE. If EVAP system did not pass leak test,
repeat step 6).

LS & Thunderbird

1) Visually Inspect Components For Small Leaks

Check for presence of fuel filler cap, but DO NOT tighten or check for proper installation at this time.
Ensure canister vent solenoid is fully seated on EVAP canister. Check EVAP hoses between EVAP
canister and EVAP canister purge valve, fuel vapor control valve tube and fuel tank, and EVAP canister
and fuel vapor vent valve for cuts or loose connections. Check fuel filler pipe for damage. If no concerns
were found, go to next step. If concern was found, repair or replace component as necessary and go to

2003 Ford Pickup F150

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

next step.

2) Check At The EVAP Test Port For Small System Leaks

Disconnect and plug EVAP emission return tube at intake manifold. Perform EVAPORATIVE
EMISSIONS SYSTEM LEAK TEST. If EVAP system does not pass leak test, go to step 4). If system
passes leak test, go to next step.

3) Visually Inspect Fuel Filler Cap

Visually inspect fuel filler cap for damage. If fuel filler cap is okay, go to next step. If fuel filler cap is
damaged, replace fuel filler cap and go to next step.

4) Check For Small Leaks At Fuel Filler Cap & EVAP Test Port

Connect Evaporative Emissions System Leak Tester (134-00056) to fuel filler pipe. 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 fuel filler
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:

z

EVAP Return Tube To EVAP Canister Purge Valve

z

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

2003 Ford Pickup F150

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

z

EVAP Canister (Canister Vent Solenoid Assembly) To Fuel Tank

z

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 Fuel Vapor Control Valve Tube

Disconnect fuel vapor control valve tube from under vehicle fuel supply and vapor tube assembly. Plug
open end of under vehicle fuel supply and vapor tube assembly. Connect evaporative emission system
leak tester to EVAP test port. 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 plugged end of
under vehicle fuel supply and vapor tube assembly. If no leak is detected, 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.

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

Connect evaporative emission system leak tester to fuel filler pipe. Transfer plug from under vehicle fuel
supply and vapor tube assembly to fuel vapor control valve tube. Set selector on evaporative emissions
system leak tester to FILL position. 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 fuel vapor control valve tube to fuel tank for leaks. Check
fuel tank pressure sensor, fuel vapor control valve tube and fuel filler pipe. Check tubes from fuel tank to
EVAP canister and to canister vent solenoid. 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 vapor control valve tube to under vehicle fuel supply and vapor tube assembly. Perform
EVAPORATIVE EMISSIONS SYSTEM LEAK TEST. If EVAP system passes leak test, perform
EVAPORATIVE EMISSION REPAIR VERIFICATION DRIVE CYCLE. If EVAP system did not
pass leak test, repeat step 6).

Ranger

1) Visually Inspect Components For Small Leaks

Check for presence of fuel filler cap, but DO NOT tighten or check for proper installation at this time.
Ensure canister vent solenoid is fully seated on EVAP canister. Check EVAP hoses between EVAP
canister and EVAP canister purge valve and EVAP canister and fuel vapor vent valve for cuts or loose
connections. Check fuel filler pipe for damage. If no concerns were found, go to next step. If concern was
found, repair or replace component as necessary and go to next step.

2) Check EVAP Test Port For Small System Leaks

2003 Ford Pickup F150

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