Ford F150 Pickup. Manual — part 1598

13) Check Repairs Between Fuel Tank & EVAP Canister

Pressurize system to 14 in. H2O (3.48 kPa). Perform EVAPORATIVE EMISSIONS SYSTEM LEAK
TEST. If system passes leak test (system pressure stays above 8 in. H2O (1.99 kPa), go to next step. If
system does not pass leak test, go to step 12).

14) Check For Fuel Tank Pressure Sensor Operation With Fuel Filler Cap Removed

Ensure battery is fully charged. Remove fuel filler cap. Connect scan tool to Data Link Connector (DLC).
Turn ignition switch to ON position. Using scan tool, access PCM FTP V PID from PID/DATA
MONITOR & RECORD menu. If FTP V PID is 2.40-2.80 volts, go to next step. If FTP V PID is not
within specification, replace fuel tank pressure sensor and repeat step 14) to verify repair.

15) Check Fuel Tank Pressure Sensor With Pressure Applied

Connect evaporative emissions system leak tester to fuel filler pipe. Disconnect and plug canister vent
hose assembly. Turn ignition switch to ON position. Using scan tool, access FTP V PID from PID/DATA
MONITOR & RECORD men. Pressurize system to 14 in. H2O (3.48 kPa). Turn ignition switch to OFF
position. If FTP V PID was 4.22-4.90 volts, go to next step. If FTP V PID was not within specification,
discontinue pressurizing EVAP system and return to step 14).

16) Check EVAP Canister Purge Valve Operation

Remove plug from canister vent hose assembly and reconnect EVAP return tube to intake manifold. Start
engine and allow to idle. Using scan tool, access EVAPPDC and FTP V PIDs. Allow engine to stay
running until PCM PID EVAPPDC reaches a duty cycle of 40 percent or more. If FTP V PID is less than
2.6 volts (zero in. H2O), perform EVAPORATIVE EMISSION REPAIR VERIFICATION DRIVE
CYCLE. If FTP V PID is not as specified, go to next step.

17) Check For Intake Manifold Vacuum At EVAP Canister Purge Valve
Disconnect input port vacuum hose and EVAP return tube from EVAP canister purge valve. Connect
vacuum gauge to input port vacuum hose and plug open end of EVAP return tube. Start engine and allow
to idle. Record vacuum measurement. Turn ignition switch to OFF position. Move vacuum gauge to
EVAP return tube and plug input port vacuum hose. Start engine and allow to idle. Record vacuum
measurement.

If both measurements are 14-20 in. Hg (47.25-67.54 kPa), replace EVAP canister purge valve. Perform
EVAPORATIVE EMISSIONS SYSTEM LEAK TEST. If system passes leak test, perform
EVAPORATIVE EMISSION REPAIR VERIFICATION DRIVE CYCLE. If both measurements are
not as specified, check for blockages in input port vacuum hose or EVAP return tube. Check intake
manifold vacuum lines or ports for blockage. Repair or replace components as necessary. Perform
evaporative emissions system leak test. See EVAPORATIVE EMISSIONS SYSTEM LEAK TEST.

F150

NOTE:

At high elevations, intake manifold vacuum reading at input port vacuum
hose and EVAP return tube must be 10 in. Hg (33. 77 kPa) or more.

2003 Ford Pickup F150

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

1) CHECK FOR DIAGNOSTIC TROUBLE CODE 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.

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. 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 6).

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 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.

5) CHECK FOR BLOCKAGE BETWEEN THE EVAP TEST PORT AND THE FUEL TANK

Connect Evaporative Emissions System Leak Tester (134-00056) to the fuel filler pipe. 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). Depress the Schrader valve in the
evaporative emission test port. If pressure drops immediately, go to step 12). 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.

6) CHECK FOR LARGE LEAK AT THE FUEL FILLER CAP

2003 Ford Pickup F150

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

Connect Evaporative Emissions System Leak Tester (134-00056) to the fuel filler pipe. 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). Perform EVAPORATIVE
EMISSIONS SYSTEM LEAK TEST. Using the ultrasonic leak detector, slowly check the fuel filler
cap. If a leak is not detected, go to next step. If a leak is detected, install a new fuel filler cap. Repeat this
step to verify repair. If no leak is detected, perform EVAPORATIVE EMISSION REPAIR
VERIFICATION DRIVE CYCLE.

7) CHECK FOR LEAK AT THE EVAP CANISTER AND CANISTER VENT SOLENOID

Plug the canister vent hose assembly. Connect Evaporative Emissions System Leak Tester (134-00056) to
the EVAP test port. Pressurize EVAP system to 14 in. H2O (3.48 kPa). Using the ultrasonic leak detector,
slowly check the EVAP canister and the canister vent solenoid. If a leak is not detected, go to next step. If
a leak is detected, install new component(s) as necessary. Perform EVAPORATIVE EMISSIONS
SYSTEM LEAK TEST. Perform EVAPORATIVE EMISSION REPAIR VERIFICATION DRIVE
CYCLE.

8) CHECK FOR LEAK BETWEEN THE EVAP TEST PORT AND THE EVAP CANISTER

Disconnect the EVAP canister outlet tube from the fuel vapor control valve tube and plug the EVAP
canister outlet tube. Connect Evaporative Emissions System Leak Tester (134-00056) to the fuel filler
pipe. 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). Using the
ultrasonic leak detector, slowly check the components from the EVAP return tube to the EVAP canister
outlet tube. If a leak is detected, repair or install new fuel vapor hoses or tubes as necessary. After repairs,
go to next step. If leak is not detected, go to step 10).

9) CHECK REPAIRS BETWEEN THE EVAP TEST PORT AND THE EVAP CANISTER

Reconnect all disconnected fittings. Perform EVAPORATIVE EMISSIONS SYSTEM LEAK TEST.
If the system passes the leak test, go to step 12). If the system does not pass the leak test, go to next step.

10) CHECK FOR LEAK FROM FUEL TANK TO EVAP CANISTER TUBE

Transfer the plug from the EVAP canister outlet tube to the fuel vapor control valve tube. Connect
Evaporative Emissions System Leak Tester (134-00056) to the fuel filler pipe. Pressurize EVAP system
to 26-28 in. H2O (6.47-6.97 kPa). Using the ultrasonic leak detector, slowly check the following
components for leaks:

z

Fuel filler pipe.

z

Fuel tank.

z

Fuel vapor vent valve assembly.

z

Fuel vapor control valve tube assembly.

z

Fuel tank pressure sensor.

z

EVAP canister tube.

z

Fuel vapor tube.

2003 Ford Pickup F150

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

If a leak is detected, repair or install new component(s) as necessary. After repairs, go to next step. If a
leak was not detected, perform EVAPORATIVE EMISSIONS SYSTEM LEAK TEST. If no leak is
detected, go to step 12).

11) CHECK REPAIRS BETWEEN THE FUEL TANK AND THE EVAP CANISTER

Reconnect all disconnected fittings. Pressurize EVAP system to 14 in. H2O (3.48 kPa). Perform
EVAPORATIVE EMISSIONS SYSTEM LEAK TEST. If the EVAP system passes the leak test and
system pressure stays above 8 in. H2O (1.99 kPa), go to next step. If the EVAP system does not pass the
leak test, go to step 10).

12) CHECK FOR FUEL TANK PRESSURE SENSOR OPERATION WITHOUT PRESSURE
APPLIED

Ensure the battery is fully charged. Disconnect the EVAP canister tube. Connect a scan tool to DLC
connector. Turn ignition switch to ON position. Access PCM PID FTP V. If the PID FTP V reading is
2.40-2.80 volts, go to next step. If the PID FTP V reading is not 2.40-2.80 volts, install a new fuel tank
pressure sensor. Repeat this step to verify repair.

13) CHECK FUEL TANK PRESSURE SENSOR WITH PRESSURE APPLIED

Connect the EVAP canister tube. Connect Evaporative Emissions System Leak Tester (134-00056) to the
fuel filler pipe. Turn ignition switch to ON position. Close canister vent solenoid. See CANISTER
VENT SOLENOID CLOSING PROCEDURE. Access PCM PID FTP V. Pressurize EVAP system to
14 in. H2O (3.48 kPa). Turn ignition switch to OFF position. If the FTP V PID reading is 4.22-4.90 volts,
go to next step. If the FTP V PID reading is not 4.22-4.90, discontinue pressurizing the EVAP system. Go
to step 12).

14) CHECK EVAP CANISTER PURGE VALVE OPERATION WITH ENGINE AT IDLE

Remove the plug and connect the EVAP return tube to the intake manifold. Turn ignition switch to ON
position. Access PCM PID EVAPPDC and FTP V. Idle the engine until PCM PID EVAPPDC reaches a
minimum of 40 percent duty cycle. Observe PID EVAPPDC and FTP V. If FTP V PID reads less than
2.60 volts (0.0 inches H2O), perform EVAPORATIVE EMISSION REPAIR VERIFICATION
DRIVE CYCLE. If FTP V PID does not read less than 2.60 volts (0.0 in. H2O), go to next step.

15) CHECK FOR INTAKE MANIFOLD VACUUM AT THE EVAP CANISTER PURGE VALVE
Disconnect the input port vacuum hose and the EVAP return tube from the EVAP canister purge valve.
Connect a vacuum gauge to the input port vacuum hose and plug the open end of the EVAP return tube.
Start engine and allow to idle. Record the vacuum reading. Turn ignition switch to OFF position. Transfer
the vacuum gauge to the EVAP return tube and plug the input vacuum hose. Start the engine and allow to
idle. Record the vacuum reading. If both vacuum gauge readings were 14-20 in. Hg (47.25-67.54 kPa),
install a new EVAP canister purge valve. Perform EVAPORATIVE EMISSIONS SYSTEM LEAK

NOTE:

At high elevations, the intake manifold vacuum source reading at both the
input port vacuum hose and EVAP return tube must be at least 10 in. Hg
(33.77 kPa).

2003 Ford Pickup F150

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