Ford F150 Pickup. Instruction - part 1361

Connect leak tester to fuel filler pipe. Pressurize system to 14 in. H2O (3.48 kPa). If pressure drops 
immediately, perform evaporative emissions system leak test. See EVAPORATIVE EMISSIONS 
SYSTEM LEAK TEST . If system passes, perform DRIVE CYCLES in SELF-DIAGNOSTICS - 
CNG, FLEX-FUEL & GASOLINE article. Ensure PENDING CODE CHECK & EVAP MONITOR 
"BYPASS" CHECK is performed. If pressure does not drop immediately, replace fuel vapor vent valve. 
Perform evaporative emissions system leak test. See EVAPORATIVE EMISSIONS SYSTEM LEAK 
TEST . If system passes, perform DRIVE CYCLES in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & 
GASOLINE article. Ensure PENDING CODE CHECK & EVAP MONITOR "BYPASS" CHECK is 
performed.  

LS & Thunderbird 

1. Testing Evaporative Emission Running Loss System Monitor - Perform DRIVE CYCLES in SELF-

DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article. Ensure PENDING CODE CHECK & 
EVAP MONITOR "BYPASS" CHECK is performed. If PCM DTCs P0442, P0455, P1443 or P1450 are 
retrieved, see EVAPORATIVE EMISSIONS DIAGNOSTIC TROUBLE CODE DEFINITIONS in 
SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article for appropriate test procedure. If any 
other PCM DTCs are retrieved, see DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-
DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article for appropriate test procedure. If no PCM 
DTCs are retrieved, go to next step. 

2. Evaporative Emission System Leak Test 

 
Perform evaporative emissions system leak test. See EVAPORATIVE EMISSIONS SYSTEM LEAK 
TEST . If system passes, go to next step. If system does not pass, go to step 9 . 

3. Testing Fuel Tank Pressure Sensor Operation 

 
Connect Evaporative Emissions System Leak Tester (134-00056) to fuel filler pipe. Turn ignition on. 
Using scan tool, close canister vent solenoid. Select OUTPUT TEST MODE, FTP and FTP V PID. Select 
ALL OFF mode. Press START button on scan tool to close canister vent solenoid. Pressurize system to 
14 in. H2O (3.48 kPa). If FTP V PID is 4.22-4.90 volts, go to next step. If FTP V PID is not 4.22-4.90 
volts, go to HISSING SOUND WHEN REMOVING FUEL CAP . 

4. Testing Vent Portion Of EVAP System 

 
Using scan tool, open canister vent solenoid. If pressure drops immediately, go to next step. If pressure 
does not drop immediately, go to HISSING SOUND WHEN REMOVING FUEL CAP . 

5. Testing Evaporative Emissions Test Port 

 
Move EVAP tester to test port. Using scan tool, close canister vent solenoid. Pressurize system to 14 in. 
H2O (3.48 kPa). If FTP V PID is 4.22-4.90 volts, evaporative emission system is operating normally. If 
FTP V PID is not 4.22-4.90 volts, go to next step. 

6. Testing Fuel Vapor Control Valve Tube 

 

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE System & Component Testing - Gasoline

  

Disconnect fuel vapor control valve tube from under vehicle fuel supply and vapor tube assembly. 
Pressurize system to 14 in. H2O (3.48 kPa). If pressure drops immediately, fuel vapor control valve tube 
or fuel tank vapor control valve is blocked. Remove the fuel tank assembly. Remove the vapor control 
tube from the tank and inspect it for any blockage or kinks. If the fuel vapor control tube is faulty, install 
a new one. If the fuel vapor control tube is not restricted, install a new fuel tank assembly. Perform 
evaporative emissions system leak test. See EVAPORATIVE EMISSIONS SYSTEM LEAK TEST . 
If system passes, perform DRIVE CYCLES in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & 
GASOLINE article. Ensure PENDING CODE CHECK & EVAP MONITOR "BYPASS" CHECK is 
performed. If pressure does not drop immediately, go to next step. 

7. Testing Under Vehicle Fuel Supply & Vapor Tube Assembly 

 
Remove left front wheel and inner fender well. Disconnect under vehicle fuel supply and vapor tube 
assembly from engine compartment fuel supply and vapor tube. Pressurize system to 14 in. H2O (3.48 
kPa). If pressure drops immediately, replace under vehicle fuel supply and vapor tube assembly. Perform 
evaporative emissions system leak test. See EVAPORATIVE EMISSIONS SYSTEM LEAK TEST . 
If system passes, perform DRIVE CYCLES in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & 
GASOLINE article. Ensure PENDING CODE CHECK & EVAP MONITOR "BYPASS" CHECK is 
performed. If pressure does not drop immediately, go to next step. 

8. Testing Engine Compartment Fuel Supply & Vapor Tube Assembly 

 
Disconnect engine compartment fuel supply and vapor tube assembly from canister purge valve. 
Pressurize system to 14 in. H2O (3.48 kPa). If pressure drops immediately, replace engine compartment 
fuel supply and vapor tube assembly. Perform evaporative emissions system leak test. See 
EVAPORATIVE EMISSIONS SYSTEM LEAK TEST . If system passes, perform DRIVE CYCLES 
in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article. Ensure PENDING CODE 
CHECK & EVAP MONITOR "BYPASS" CHECK is performed. If pressure does not drop immediately, 
replace EVAP canister purge valve. Perform evaporative emissions system leak test. See 
EVAPORATIVE EMISSIONS SYSTEM LEAK TEST . If system passes, perform DRIVE CYCLES 
in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article. Ensure PENDING CODE 
CHECK & EVAP MONITOR "BYPASS" CHECK is performed. 

9. Testing For Location Of Leak 

 
Connect EVAP tester to fuel filler pipe. Disconnect fuel vapor control valve tube from under vehicle fuel 
supply and vapor tube assembly. Plug both tube open ends. Perform evaporative emissions system leak 
test. See EVAPORATIVE EMISSIONS SYSTEM LEAK TEST . If system passes, leaks are in front 
portion of EVAP system, go to next step. If system does not pass, leaks are in rear portion of EVAP 
system, go to step 14 . 

10. Testing To Confirm Leak In Front Portion Of EVAP System 

 
Move EVAP tester to test port. Plug the under-vehicle fuel supply and vapor tube assembly. Perform 
evaporative emissions system leak test. See EVAPORATIVE EMISSIONS SYSTEM LEAK TEST . 
If system does not pass, go to next step. If system passes, replace "O" ring seals between fuel vapor 
control valve tube and under vehicle fuel supply and vapor tube assembly. Reconnect all components. 

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE System & Component Testing - Gasoline

  

Perform evaporative emissions system leak test. If system passes, perform DRIVE CYCLES in SELF-
DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article. Ensure PENDING CODE CHECK & 
EVAP MONITOR "BYPASS" CHECK is performed. 

11. Testing Under Vehicle Fuel Supply & Vapor Tube Assembly 

 
Remove left front wheel and inner fender well. Disconnect under vehicle fuel supply and vapor tube 
assembly from engine compartment fuel supply and vapor tube assembly. Plug engine compartment fuel 
supply and vapor tube assembly. Perform evaporative emissions system leak test. See EVAPORATIVE 
EMISSIONS SYSTEM LEAK TEST . If system did not pass, go to next step. If system passes, replace 
under vehicle fuel supply and vapor tube assembly. Reconnect all components. Perform evaporative 
emissions system leak test. If system passes, perform DRIVE CYCLES in SELF-DIAGNOSTICS - 
CNG, FLEX-FUEL & GASOLINE article. Ensure PENDING CODE CHECK & EVAP MONITOR 
"BYPASS" CHECK is performed. 

12. Testing Engine Compartment Fuel Supply & Vapor Tube Assembly 

 
Disconnect engine compartment fuel supply and vapor tube assembly from canister purge valve. Plug 
EVAP canister purge valve. Perform evaporative emissions system leak test. See EVAPORATIVE 
EMISSIONS SYSTEM LEAK TEST . If system did not pass, go to next step. If system passes, replace 
engine compartment fuel supply and vapor tube assembly. Reconnect all components. Perform 
evaporative emissions system leak test. If system passes, perform DRIVE CYCLES in SELF-
DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article. Ensure PENDING CODE CHECK & 
EVAP MONITOR "BYPASS" CHECK is performed. 

13. Testing EVAP Canister Purge Valve 

 
Disconnect evaporative emission return tube from EVAP canister purge valve. Plug EVAP canister purge 
valve. Perform evaporative emissions system leak test. See EVAPORATIVE EMISSIONS SYSTEM 
LEAK TEST . If system passes, replace evaporative emission return tube. Reconnect all components. 
Perform evaporative emissions system leak test. If system passes, perform DRIVE CYCLES in SELF-
DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article. Ensure PENDING CODE CHECK & 
EVAP MONITOR "BYPASS" CHECK is performed. If system did not pass, replace EVAP canister 
purge valve. Reconnect all components. Perform evaporative emissions system leak test. If system passes, 
perform DRIVE CYCLES in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article. 
Ensure PENDING CODE CHECK & EVAP MONITOR "BYPASS" CHECK is performed. 

14. Testing To Determine Is In EVAP Canister Or Fuel Tank Portion Of System 

 
Disconnect fuel vapor control valve tube from EVAP canister purge outlet tube. Plug open end of fuel 
vapor control valve tube. Perform evaporative emissions system leak test. See EVAPORATIVE 
EMISSIONS SYSTEM LEAK TEST . If system passes, reconnect all components and go to next step. 
If system does not pass, go to step 20 . 

15. Testing EVAP Canister Vent Solenoid 

 
Reconnect fuel vapor control valve tube. Lower differential to gain access to canister vent solenoid. See 

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE System & Component Testing - Gasoline

  

appropriate DIFFERENTIALS article in DRIVE AXLES. Disconnect canister vent solenoid from canister 
vent hose. Perform evaporative emissions system leak test. See EVAPORATIVE EMISSIONS 
SYSTEM LEAK TEST . If system does not pass, go to next step. If system passes, replace canister vent 
solenoid. Reconnect all components. Perform evaporative emissions system leak test. If system passes, 
perform DRIVE CYCLES in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article. 
Ensure PENDING CODE CHECK & EVAP MONITOR "BYPASS" CHECK is performed. 

16. Testing Canister Vent Solenoid Hose Assembly 

 
Reinstall differential. Lower rear subframe to access EVAP canister and bracket assembly. Remove 
EVAP canister and bracket assembly. Move EVAP tester to EVAP canister purge outlet tube. See Fig. 8 . 
Disconnect canister vent solenoid hose from 1.0L EVAP canister. Pressurize system to 14 in. H2O (3.48 
kPa). If pressure holds, replace canister vent solenoid hose assembly. Reconnect all components. Perform 
evaporative emissions system leak test. See EVAPORATIVE EMISSIONS SYSTEM LEAK TEST . 
If system passes, perform DRIVE CYCLES in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & 
GASOLINE article. Ensure PENDING CODE CHECK & EVAP MONITOR "BYPASS" CHECK is 
performed. If pressure does not hold, go to next step. 

17. Testing 1.0L EVAP Canister 

 
Disconnect fuel vapor storage EVAP canister inlet tube at 1.0L EVAP canister and plug inlet tube. See 
Fig. 8 . Pressurize system to 14 in. H2O (3.48 kPa). If pressure holds, replace 1.0L EVAP canister. 
Reconnect all components. Perform evaporative emissions system leak test. See EVAPORATIVE 
EMISSIONS SYSTEM LEAK TEST . If system passes, perform DRIVE CYCLES in SELF-
DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article. Ensure PENDING CODE CHECK & 
EVAP MONITOR "BYPASS" CHECK is performed. If pressure does not hold, go to next step. 

18. Testing Fuel Vapor Storage Canister Inlet Tube 

 
Disconnect fuel vapor storage canister inlet tube from 2.0L EVAP canister and plug EVAP canister. See 
Fig. 8 . Pressurize system to 14 in. H2O (3.48 kPa). If pressure holds, replace fuel vapor storage canister 
inlet tube. Reconnect all components. Perform evaporative emissions system leak test. See 
EVAPORATIVE EMISSIONS SYSTEM LEAK TEST . If system passes, perform DRIVE CYCLES 
in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article. Ensure PENDING CODE 
CHECK & EVAP MONITOR "BYPASS" CHECK is performed. If pressure does not hold, go to next 
step. 

19. Testing 2.0L EVAP Canister 

 
Disconnect EVAP canister purge outlet tube at 2.0L EVAP canister and plug outlet tube. See Fig. 8 . 
Pressurize system to 14 in. H2O (3.48 kPa). If pressure holds, replace 2.0L EVAP canister. Reconnect all 
components. Perform evaporative emissions system leak test. See EVAPORATIVE EMISSIONS 
SYSTEM LEAK TEST . If system passes, perform DRIVE CYCLES in SELF-DIAGNOSTICS - 
CNG, FLEX-FUEL & GASOLINE article. Ensure PENDING CODE CHECK & EVAP MONITOR 
"BYPASS" CHECK is performed. If pressure does not hold, replace EVAP canister purge outlet tube. 
Reconnect all components. Perform evaporative emissions system leak test. See EVAPORATIVE 
EMISSIONS SYSTEM LEAK TEST . If system passes, perform DRIVE CYCLES in SELF-

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE System & Component Testing - Gasoline