Ford F150 Pickup. Instruction — part 1610

Check for contaminated Mass Airflow (MAF) sensor. Check air intake system.

Additional Intermittent Testing

Go to TEST Z: INTERMITTENT , step 1) under SYSTEM TESTS in SELF-DIAGNOSTICS - CNG, FLEX-
FUEL & GASOLINE article.

VEHICLE FAILS EMISSIONS/EMISSIONS COMPLIANCE

For emissions compliance procedures, see EMISSIONS COMPLIANCE under EMISSION SYSTEMS &
SUB-SYSTEMS in SYSTEM & COMPONENT TESTING - GASOLINE article.

HISSING SOUND WHEN REMOVING FUEL CAP

For diagnostic procedures, see HISSING SOUND WHEN REMOVING FUEL CAP symptom under
SYSTEM TESTS (EVAPORATIVE EMISSION) in SYSTEM & COMPONENT TESTING - GASOLINE
article.

EXCESSIVE FUEL ODOR

For diagnostic procedures, see EXCESSIVE FUEL ODOR symptom under SYSTEM TESTS
(EVAPORATIVE EMISSION) in SYSTEM & COMPONENT TESTING - GASOLINE article.

UNABLE TO REFUEL VEHICLE

For diagnostic procedures, see UNABLE TO REFUEL VEHICLE symptom under SYSTEM TESTS
(EVAPORATIVE EMISSION) in SYSTEM & COMPONENT TESTING - GASOLINE article.

WARNING INDICATOR LIGHTS

The following warning indicators may illuminate:

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Malfunction Indicator Light (MIL)

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Transmission Control Indicator Light (TCIL)

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Shift Indicator Light (SIL)

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Temperature Warning Indicator Light Or Gauge - Models With Cylinder Head Temperature (CHT)
Sensor

NOTE:

If exhaust emission test fails and Malfunction Indicator Light (MIL) is on,
perform EMISSIONS COMPLIANCE procedures under EMISSION SYSTEMS &
SUB-SYSTEMS in SYSTEM & COMPONENT TESTING - GASOLINE article. If MIL
is illuminated and engine is a no-start, perform NO START/NORMAL CRANK
symptom diagnosis first. If MIL is illuminated and engine runs rough at idle,
perform ROUGH OR ROLLING IDLE, STALLS, MISSES, HESITATION OR SURGE
symptom diagnosis first.

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE Trouble Shooting - No Codes - CNG, Flex-Fuel & Gasoline

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Check Fuel Cap Indicator Light

Preliminary Check

Check wiring harness connectors. Ensure fuel filler cap is installed and tightened properly.

Pickups With Power Takeoff (PTO) & MIL Concern

Check PTO input to PCM. Go to TEST FB: POWER TAKE OFF , step 3) under SYSTEM TESTS in SELF-
DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article.

MIL Always On When Engine Is Running, No DTCs Are Present

Check MIL circuits. On Aviator, Escape, Expedition, Focus, F150 Pickup, LS, Mustang, Navigator,
Thunderbird, Town Car or Windstar, see appropriate INSTRUMENT PANELS article in ACCESSORIES &
EQUIPMENT. On all other models, go to TEST NB: MALFUNCTION INDICATOR LIGHT , step 1)
under SYSTEM TESTS in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article.

TCIL Always On When Engine Is Running, No DTCs Are Present

Check TCIL circuits. On Aviator, Expedition, Focus, LS, Mustang, Navigator, Thunderbird, Town Car or
Windstar, see appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. On all other
models, go to TEST TB: TRANSMISSION CONTROL SWITCH/TRANSMISSION CONTROL
INDICATOR LAMP , step 6) under SYSTEM TESTS in SELF-DIAGNOSTICS - CNG, FLEX-FUEL &
GASOLINE article.

MIL Inoperative (Including Bulb Check When Engine Is First Started)

Check MIL circuits. On Aviator, Escape, Expedition, Focus, F150 Pickup, LS, Mustang, Navigator,
Thunderbird, Town Car or Windstar, see appropriate INSTRUMENT PANELS article in ACCESSORIES &
EQUIPMENT. On all other models, go to TEST NB: MALFUNCTION INDICATOR LIGHT , step 2)
under SYSTEM TESTS in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article.

Transmission Control Indicator (TCIL) Inoperative

Check TCIL circuits. On Aviator, Expedition, Focus, LS, Mustang, Navigator, Thunderbird, Town Car or
Windstar, see appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. On all other
models, go to TEST TB: TRANSMISSION CONTROL SWITCH/TRANSMISSION CONTROL
INDICATOR LAMP , step 8) under SYSTEM TESTS in SELF-DIAGNOSTICS - CNG, FLEX-FUEL &
GASOLINE article.

Temperature Warning Indicator Light Or Temperature Gauge Inoperative (Models With CHT Sensor Only)

Check cooling system or indicator light circuits. If engine is overheating, note that since a PCM DTC was not
retrieved, PCM has not attempted to illuminate light. Check and repair cooling system as necessary. If cooling
system is operating at normal operating temperature, go to TEST DL: CYLINDER HEAD TEMPERATURE
SENSOR , step 40) under SYSTEM TESTS in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE Trouble Shooting - No Codes - CNG, Flex-Fuel & Gasoline

article.

SIL Always On Or Inoperative

Check SIL circuits. Go to TEST KL: SHIFT INDICATOR LIGHT , step 1) under SYSTEM TESTS in
SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article.

Fuel Cap Indicator Light Always On Or Inoperative

Check fuel indicator light circuits. On Crown Victoria, Escape, Explorer Sport, Explorer Sport Trac, Focus,
F150 Pickup (except Lightning), Grand Marquis, Ranger, Sable or Taurus, if check fuel indicator light is always
ON, go to TEST HX: EVAPORATIVE EMISSION MONITOR & SYSTEM , step 88) under SYSTEM
TESTS in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article. For check fuel indicator light is
always OFF, go to TEST HX: EVAPORATIVE EMISSION MONITOR & SYSTEM , step 89) under
SYSTEM TESTS in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article. On all other models,
see appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT.

Additional Intermittent Testing

Go to TEST Z: INTERMITTENT , step 1) under SYSTEM TESTS in SELF-DIAGNOSTICS - CNG, FLEX-
FUEL & GASOLINE article.

AUTOMATIC TRANSMISSION DOWN OR UPSHIFT, OR ENGAGEMENT CONCERN

Preliminary Checks

Check Automatic Transmission Fluid (ATF) level and condition. Check wiring harness connectors. Check for
vehicle modifications. Check for electronic add-on items. Check for misadjusted shift linkage.

Miscellaneous Component Or System Checks

Check A/T mechanical components and A/T shift solenoids and Torque Converter Clutch (TCC) solenoid
operation. See appropriate OVERHAUL or DIAGNOSIS article in AUTOMATIC TRANSMISSIONS.

Additional Intermittent Testing

Go to TEST Z: INTERMITTENT , step 1) under SYSTEM TESTS in SELF-DIAGNOSTICS - CNG, FLEX-
FUEL & GASOLINE article.

SPEEDOMETER OR TACHOMETER INOPERATIVE

Preliminary Checks

Check wiring harness connectors for loose, damaged or corroded terminals.

Tachometer Inoperative On Models With Clean Tach Output (CTO) Only

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE Trouble Shooting - No Codes - CNG, Flex-Fuel & Gasoline

Check CTO circuit from PCM terminal No. 48. Go to TEST JH: TACHOMETER OUTPUT FAILURE ,
step 1) under SYSTEM TESTS in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article. To
determine if CTO circuit is used, see appropriate PIN VOLTAGE/PID VALUE CHARTS article. Check
terminal No. 48 under OUTPUTS.

Speedometer/Odometer Inoperative On Models With Instruction Shift On-The-Fly (MSOF) Only

Check Transfer Case Speed Sensor (TCSS) circuits. Go to TEST DP: VEHICLE SPEED
SENSOR/TRANSFER CASE SPEED SENSOR , step 30) under SYSTEM TESTS in SELF-DIAGNOSTICS
- CNG, FLEX-FUEL & GASOLINE article.

Boost Gauge Indicates higher than normal Boost

Check supercharger bypass control intercooler system. For supercharger bypass control, go to TEST KJ:
SUPERCHARGER BY-PASS CONTROL , step 1) . For intercooler system, go to TEST KP: CHARGE
AIR COOLER PUMP , step 7) .

Additional Checks

Check instrumentation. See appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT.

HIGH OIL CONSUMPTION

Preliminary Checks

Check for external engine oil leaks. Check for correct oil dipstick. Check for proper oil viscosity.

Miscellaneous Component Or System Checks

Check the following:

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Check PCV system. For Aviator and Mustang 4.6L, go to TEST HG: PCV SYSTEM , step 1) under
SYSTEM TESTS in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article. For all others,
go to TEST HG: PCV SYSTEM , step 4) under SYSTEM TESTS in SELF-DIAGNOSTICS - CNG,
FLEX-FUEL & GASOLINE article.

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Check engine mechanical condition. Check valves, valve guides, valve stem oil seals, intake manifold
gaskets, cylinder head oil drain passages and piston rings. See appropriate article in ENGINES.

ELECTRIC, HYDRAULIC OR VISCTRONIC COOLING FAN INOPERATIVE

Preliminary Checks

Perform the following checks:

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Engine coolant level.

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Cooling fan wiring harness connections.

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE Trouble Shooting - No Codes - CNG, Flex-Fuel & Gasoline