Ford F150 Pickup. Manual - 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