Ford F150 Pickup. Manual - part 1356

35) EVAP System Concern: Preliminary Checks 
Analyze I/M test report to determine when concern is present. Verify concern and inspect and repair the 
following as necessary: 

z

Check fuel filler cap for proper installation, physical damage or contamination.  

z

Check EVAP system hoses and lines for proper connection, damage or blockage.  

z

Check fuel vapor storage canister for damage.  

If all checks are okay, go to next step. If repairs have been performed, go to step 38) to verify repairs. 

36) Perform PCM Quick Test 
 
Perform QUICK TEST in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article to retrieve 
Diagnostic Trouble Codes (DTCs). If no DTCs are present, go to next step. If DTCs are present, service 
DTC. See DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - CNG, 
FLEX-FUEL & GASOLINE article to service appropriate DTC, then go to step 38) to verify repairs. 

37) Check EVAP Emissions System For Leaks 
 
See appropriate symptom under EVAPORATIVE EMISSION SYSTEM TESTS . Follow diagnostic 
procedures and repair as necessary, then go to step 38) . If EVAP emission system is okay, verify test 
results. If results are okay, go to TEST Z: INTERMITTENT , step 1) under SYSTEM TESTS in SELF-
DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article, or return to SYMPTOM DIAGNOSIS 
under SYMPTOMS in TROUBLE SHOOTING - NO CODES - CNG, FLEX-FUEL & GASOLINE 
article to repair any additional symptoms. Follow diagnostic procedures and repair as necessary, then go 
to step 38) . 

38) EVAP Emissions System Repair Verification 
 
After making repairs to EVAP emissions system, reset KAM and relearn basic adaptive strategy. See 
KEEP ALIVE RANDOM ACCESS MEMORY RESET PROCEDURE under CLEARING CODES 
under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE 
article. Repeat QUICK TEST in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article. 
Repair any DTCs that may be retrieved and perform EVAPORATIVE EMISSIONS SYSTEM LEAK 
TEST under EVAPORATIVE EMISSION SYSTEM TESTS. If original concern has not been corrected 
or if another concern exists, repeat step 1) . 

40) Repair Verification 
After making repairs to appropriate system, reset KAM and relearn basic adaptive strategy. See KEEP 
ALIVE RANDOM ACCESS MEMORY RESET PROCEDURE under CLEARING CODES under 
SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article. 
Repeat QUICK TEST in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article. Repair 

from step 31) to step 35) . No test procedures have been omitted.

NOTE:

A break in step numbering sequence occurs at this point. Procedure skips 
from step 38) to step 40) . No test procedures have been omitted.

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE System & Component Testing - Gasoline

  

any DTCs that may be retrieved. Repeat baseline test using gas analyzer. If vehicle requires driving for 
the baseline test, drive at least 5 miles to relearn some additional Adaptive Learning Strategy (trim 
values). Ensure same drive mode is used as original baseline test performed in step 3) . If all gas levels 
are within acceptable range, save all repair documentation that may be required by local or federal law 
and return vehicle to customer. If any gas level is not within acceptable range, go to step 1) . 

45) Catalyst Delta Temperature Test 
Disable secondary AIR system, if equipped. Start and run engine for 2 minutes at 2500 RPM to heat 
exhaust system. Turn ignition switch to OFF position. Disconnect and ground one spark plug wire from 
each cylinder bank (for Coil On Plug applications, disconnect one coil connector from each cylinder 
bank). Start and run engine at 1000 RPM. Disconnect Idle Air Control (IAC) valve while maintaining 
1000 RPM. Using an infrared temperature probe, measure temperature at both the inlet and outlet of each 
catalytic converter. If the temperature difference between inlet and outlet of each catalytic converter is 
50°F (28°C) or less, testing indicates catalytic converter is not operating correctly. Repeat test step to 
verify readings. If temperature differences are still 50°F (28°C) or less, replace affected catalytic 
converter. Reconnect all connectors, IAC valve and AIR system. Go to step 40) to verify repairs. If the 
temperature difference between inlet and outlet of each catalytic converter is more than 50°F (28°C), the 
catalytic converters are operating correctly. Reconnect all connectors, IAC valve and AIR system. 
Perform PCM RESET PROCEDURE under CLEARING CODES under SELF-DIAGNOSTIC 
SYSTEM in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article. Repeat QUICK TEST 
to clear any DTCs set during testing. See QUICK TEST in SELF-DIAGNOSTICS - CNG, FLEX-FUEL 
& GASOLINE article. Verify previous test results. If results are okay, go to TEST Z: 
INTERMITTENT , step 1) under SYSTEM TESTS in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & 
GASOLINE article. Follow diagnostic procedures and repair as necessary, then go to step 40) to verify 
repairs.  

FUEL EVAPORATION 

SECONDARY AIR INJECTION 

For additional Secondary Air Injection (AIR) system testing and specifications, see TEST HM: 
SECONDARY AIR INJECTION SYSTEM under SYSTEM TESTS in SELF-DIAGNOSTICS - CNG, 
FLEX-FUEL & GASOLINE article. 

EGR SYSTEMS 

Electric Exhaust Gas Recirculation 

NOTE:

A break in step numbering sequence occurs at this point. Procedure skips 
from step 40) to step 45) . No test procedures have been omitted.

NOTE:

For testing of EVAP emission system and/or EVAP component not found here, 
perform appropriate symptom test under EVAPORATIVE EMISSION SYSTEM 
TESTS , or TEST HX: EVAPORATIVE EMISSION MONITOR & SYSTEM under 
SYSTEM TESTS in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article.

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE System & Component Testing - Gasoline

  

For additional Electric Exhaust Gas Recirculation (EEGR) system testing and specifications, see TEST KD: 
ELECTRIC EXHAUST GAS RECIRCULATION under SYSTEM TESTS in SELF-DIAGNOSTICS - 
CNG, FLEX-FUEL & GASOLINE article. 

Exhaust Gas Recirculation 

1. Ensure all vacuum hoses are correctly routed and securely attached. Replace any crimped or broken 

hoses. Ensure there is less than one in. Hg vacuum to EGR valve at idle with engine at normal operating 
temperature. Install tachometer. Disconnect Idle Air Control (IAC) wiring harness connector. Remove 
and plug vacuum hose at EGR valve. Place transmission in Neutral.  

2. Start and operate engine at idle. Note idle speed. Using a hand-held vacuum pump, slowly apply 5-10 in. 

Hg vacuum to EGR valve. When vacuum is fully applied, engine should do one or more of the following: 

z

Engine should stall.  

z

Idle speed should drop more than 100 RPM.  

z

Idle speed should return to normal when vacuum is released.  

3. Service or replace EGR valve if engine does not stall or idle speed does not respond as specified. 

Reconnect IAC harness connector. Unplug and reconnect vacuum hose at EGR valve. For additional EGR 
system testing and specifications, go to TEST HE: EGR SYSTEM under SYSTEM TESTS in SELF-
DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article.  

POSITIVE CRANKCASE VENTILATION (AVIATOR & MUSTANG 4.6L) 

1) Check Power And Ground Circuits At Heated PCV Valve 
 
Disconnect the heated PCV valve harness connector. Start engine. Measure the voltage at the heated PCV 
valve harness connector. If the voltage is greater than 10.5 volts, go to next step. If the voltage is 10.5 
volts or less, go to step 3) . 

2) Check Resistance Of Heated PCV Valve 
 
Measure the resistance between both pins at the heated PCV valve. If the resistance reading is 28-35 
ohms, go to step 4) . If the resistance reading is not 28-35 ohms, replace heated PCV valve. 

3) Check Battery Voltage To Heated PCV Valve Circuit 
 
Measure B(+) circuit voltage at the heated PCV valve harness connector. If the voltage greater than 10.5 
volts, check the heated PCV valve ground circuit. Repair as necessary. Turn ignition switch to OFF 
position. Check condition of related fuse(s). If okay, repair open circuit. If fuse is damaged, check B(+) 
circuit for short to ground before replacing. 

4) Stuck PCV Valve Check 
 

NOTE:

Use this test to diagnose Positive Crankcase Ventilation (PCV) valve and related 
vacuum hoses only.

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE System & Component Testing - Gasoline

  

Ensure PCV valve maintenance schedule has been followed. Ensure proper PCV valve is installed. 
Remove PCV valve. Shake valve and listen for rattle. If PCV valve rattles when shaken, install PCV 
valve and go to next step. Replace PCV valve if it does not rattle when shaken. Verify repair. 

5) PCV System Check 
 
Start engine and warm to normal operating temperature. Disconnect fresh air hose from remote air cleaner 
or outlet tube connecting MAF sensor to throttle body. Place a stiff piece of paper over end of hose. If 
vacuum from hose does not hold paper in place for one minute, go to next step. If vacuum from hose 
holds paper in place for one minute, PCV system is okay. Return to appropriate symptom under 
SYMPTOMS in TROUBLE SHOOTING - NO CODES - CNG & GASOLINE article to complete 
testing. 

6) Evaporative Emission System Check 
 
Disconnect evaporative emission hose from PCV system and plug connector. Again, place a stiff piece of 
paper over end of hose. If vacuum from hose does not hold paper in place for one minute, isolate vacuum 
leak or restriction in PCV system and repair as necessary. If vacuum from hose holds paper in place for 
one minute, PCV system is working properly at this time. Go to EVAPORATIVE EMISSION 
SYSTEM TESTS to diagnose EVAP system vacuum leak.  

EVAPORATIVE EMISSION SYSTEM TESTS 

CANISTER VENT SOLENOID CLOSING PROCEDURE 

Connect scan tool to DLC. Turn ignition on. Using scan tool, select OUTPUT TEST MODE. Select FTP and 
FTP V PID from PID/DATA MONITOR & RECORD menu. Select ALL OFF mode. Close canister vent 
solenoid by pressing START button on scan tool. 

EVAPORATIVE EMISSIONS SYSTEM LEAK TEST 

Connect Evaporative Emissions System Leak Tester (134-00056) to EVAP test port. Close canister vent 
solenoid. See CANISTER VENT SOLENOID CLOSING PROCEDURE . Pressurize EVAP system to 14 
in. H2O (3.48 kPa). Monitor system pressure for 2 minutes. EVAP system pressure should not fall below 8 in. 
H2O (2 kPa). Repair leaks as necessary. Repeat EVAP system leak test until system pressure remains greater 
than 8 in. H2O (2 kPa) after 2 minutes. 

HISSING SOUND WHEN REMOVING FUEL CAP 

NOTE:

For additional evaporative emission system testing and DTC-related 
procedures, see EVAPORATIVE EMISSIONS DIAGNOSTIC TROUBLE CODE 
DEFINITIONS in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article.

NOTE:

For testing EVAP canister vent solenoid or EVAP canister purge valve, see 
EVAP CANISTER VENT SOLENOID or EVAP CANISTER PURGE VALVE under 
RELAYS & SOLENOIDS.

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE System & Component Testing - Gasoline