Ford F150 Pickup. Manual — part 1379

Fig. 26: Locating ALT Fuel Switch
Courtesy of FORD MOTOR CO.

Safe Fuel Handling Practices - Gasoline And CNG

Fire

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Report all fires to the appropriate authorities.

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Know the locations of portable fire extinguishers, fire blankets, fire alarms and eyewash shower facilities.
Learn how to use them.

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Use a B or AFFF (light water) type fire extinguisher to fight flammable liquid fires.

First Aid

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If gasoline has been swallowed, do not induce vomiting. Seek medical attention immediately.

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When someone is overcome by vapors, if safe, move victim to fresh air. If not breathing, give artificial
respiration or Cardiopulmonary Resuscitation (CPR) as appropriate. Seek medical attention immediately.

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If splashed in eyes, flush with large amounts of water for 15 minutes. Remove contact lenses, if worn.
Seek medical attention.

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If splashed on skin, remove contaminated clothing. WASH SKIN thoroughly with soap and water.

Health

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE Self-Diagnostics - Bi-Fuel - Gasoline/CNG

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All fuels may be harmful or fatal if swallowed.

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Be aware: if swallowed, onset of serious health effects may be delayed 12 to 24 hours.

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All fuel vapors may be harmful by inhalation.

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All fuels may be harmful by skin absorption.

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All fuels are irritating to the eyes and respiratory system.

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Fuels made with gasoline may contain benzene, which is a cancer-causing agent.

Handling

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Use flammable liquid handling precautions.

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Do not smoke or use heat/spark producing equipment near vapors.

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Do not eat, smoke or drink where fuel products are handled, processed or stored.

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Wear chemical goggles and nitrile gloves (additional protective clothing and equipment may be necessary
in some instances).

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Never siphon by mouth.

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Use in well-ventilated areas, and control vapors. Be aware that gasoline and CNG vapors are not visible.
Gasoline vapors are heavier than air, can travel along the floor, and will settle in lower areas.

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Keep flammable fuels in approved, labeled, closed containers.

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When transferring or venting flammable fuels, bond the receiving container to the source and ground the
source to the earth.

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Wash hands thoroughly after handling any fuel.

Testing

1) Check System Integrity

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Visually inspect the complete fuel delivery system, including fuel lines, connections, pump,
pressure regulator and injector areas for leaks, looseness, cracks, kinks, pinching, or abrasion
caused by an accident, collision, mishandling and other causes.

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Visually inspect electrical harness and connectors.

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Verify vehicle has followed maintenance schedule.

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Check service history on the fuel filter. Replace if required per the scheduled maintenance interval.

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Verify Inertia Fuel Shutoff (IFS) switch set.

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Verify vehicle battery is fully charged.

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Verify electrical/relay integrity.

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Verify sufficient fuel in the tank and fill if necessary (pressure minimum of 900 psi (6205 kPa)
when monitoring TANKPR PID, and 1/4 tank fill level).

Has any problem been found? If yes, repair as necessary. If no, go to next step.

2) Carry Out The Cylinder Power Balance Test In Gasoline Mode

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE Self-Diagnostics - Bi-Fuel - Gasoline/CNG

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Carry out the cylinder power balance test in gasoline mode.

Is there a noticeable power loss in one or more cylinders? If yes, see SELF-DIAGNOSTICS - CNG,
FLEX-FUEL & GASOLINE article. If no, go to next step.

3) Road Test The Vehicle In ALT Fuel Mode

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Road test the vehicle at highway speeds in ALT fuel mode.

Is there a surge present? If yes, fuel is contaminated, bleed the system. Replace the ALT fuel system
filter. Road test the vehicle. If the surge is still present, go to step 5) . If no, go to next step.

4) Carry Out The Cylinder Power Balance Test In ALT Fuel Mode

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Carry out the cylinder power balance test in ALT fuel mode.

Is there a noticeable power loss in one or more cylinders? If yes, go to next step. If no, see SYMPTOMS
in TROUBLE SHOOTING - NO CODES - BI-FUEL - GASOLINE/CNG article to continue symptom
diagnosis.

5) Check The ALT Fuel System Pressure

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Connect the scan tool.

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Key on, engine off.

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Access the AFCM.

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Select the FRPREAB PID.

Is the fuel rail pressure 75-120 psi (517-827 kPa)? If yes, go to next step. If no, install a new fuel pressure
regulator.

6) Check The ALT Fuel System Ability To Maintain Pressure

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Key on, engine running.

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Access the AFCM.

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Select the FRPREAB PID.

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Increase the engine speed to 2500 RPM.

Is the fuel pressure 75-120 psi (517-827 kPa) at idle; and is the fuel pressure greater than 80 psi (552 kPa)
at 2500 RPM? If yes, go to next step. If no, visually inspect fuel lines for restrictions. Install a new fuel
pressure regulator.

7) Check The ALT Fuel Injector Flow

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Key off.

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE Self-Diagnostics - Bi-Fuel - Gasoline/CNG

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Connect the electronic fuel injector tester to the suspect fuel injector.

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Access the AFCM.

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Select the FRPREAB PID.

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Key on, engine off. Record the value at key on.

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Select pulse width of 200 msec.

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Record the FRPREAB PID value.

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Activate the fuel injector tester.

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Subtract the final pressure from the initial pressure reading.

Is the pressure drop within 35 to 50 psi and all fuel injectors within 3 psi of each other? If yes, see
SYMPTOMS in TROUBLE SHOOTING - NO CODES - BI-FUEL - GASOLINE/CNG article to
continue symptom diagnosis. If no, install a new fuel injector for the cylinder that does not meet pressure
specification.

TEST NB: ALT FUEL INDICATOR

Diagnostic Aids

Enter this test only when all steps under QUICK TEST have been successfully completed and engine still does
not start or if directed here from another test or chart. This test is only intended to diagnose:

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ALT Fuel Switch

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AFCM

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Circuitry

Testing

1) Check The ALT Fuel Switch Operation In Gas Position

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Key off.

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Place the ALT fuel switch in the GAS position.

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Key on, engine off.

Is the ALT fuel indicator illuminated? If yes, go to next step. If no, go to step 7) .

2) Check The ALT Fuel Switch Circuit Input

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Key off.

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Connect the scan tool.

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Key on, engine off.

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Access the AFCM.

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Select the SEL_SW PID.

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE Self-Diagnostics - Bi-Fuel - Gasoline/CNG