Ford F150 Pickup. Instruction — part 1459

step 9). If secondary ignition on all other vehicles is okay, go to next step.

WARNING:

Always refer to safety procedures to reduce possibility of injury. See
FUEL SYSTEM SAFETY PRECAUTIONS.

2003 Ford Pickup F150

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

Fig. 167: Fuel System Types, Fuel Injector Resistances & Pressure Specifications
Courtesy of FORD MOTOR CO.

7) Check Fuel Pressure

2003 Ford Pickup F150

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

Turn ignition switch to OFF position. Release fuel pressure. See FUEL SYSTEM PRESSURE RELEASE
under FUEL SYSTEMS in appropriate REMOVAL & INSTALLATION article. Install fuel pressure
gauge. With scan tool connected, turn ignition switch to ON position. Using scan tool, access OUTPUT
TEST MODE. See OUTPUT TEST MODE under ADDITIONAL SYSTEM FUNCTIONS. Command
fuel pump ON. If fuel pressure is as specified, go to next step. See Fig. 167. If fuel pressure is not as
specified, turn ignition switch to OFF position and go to TEST HC, step 1).

8) Check Fuel Pressure Leakdown

Leave fuel pressure gauge installed and ignition switch turned to ON position. Using scan tool, access
OUTPUT TEST MODE. See OUTPUT TEST MODE under ADDITIONAL SYSTEM FUNCTIONS.
Command fuel pump ON to obtain maximum fuel pressure. Exit OUTPUT TEST MODE and turn
ignition switch to OFF position. If fuel pressure remains within 5 psi (34 kPa) of maximum pressure for
one minute after turning ignition switch to OFF position, go to next step. If fuel pressure does not remain
within 5 psi (34 kPa), go to TEST HC, step 1).

9) Check VPWR Circuit At Fuel Injectors
Disconnect at least 2 fuel injector connectors, one from each bank. Turn ignition switch to ON position.
Using a DVOM, measure voltage of VPWR circuit at disconnected fuel injector connectors. If any
voltage measurement is 10.5 volts or less, repair VPWR circuit. If voltage measurements are more than
10.5 volts, go to step 15) (natural gas vehicles), or go to next step (all other vehicles).

10) Check Fuel Injectors Ability To Deliver Fuel
Turn ignition switch to OFF position. Release fuel pressure. See appropriate FUEL SYSTEM
PRESSURE RELEASE procedure under FUEL SYSTEM VENTING in REMOVAL &
INSTALLATION article. Install fuel pressure gauge. Cycle ignition switch to ON and then to OFF
positions several times. Locate and disconnect Inertia Fuel Shutoff (IFS) switch connector. See
INERTIA FUEL SHUTOFF SWITCH LOCATIONS table. Monitor fuel pressure gauge while
cranking engine for at least 5 seconds. If fuel pressure drops more than 5 psi (34 kPa) while cranking
engine, EEC system is not cause of no-start. Return to NO-START/NORMAL CRANK symptom under
SYMPTOMS in TROUBLE SHOOTING - NO CODES - CNG, FLEX-FUEL & GASOLINE article. If
fuel pressure does not drop more than 5 psi (kPa), replace PCM.

INERTIA FUEL SHUTOFF SWITCH LOCATIONS

NOTE:

A no-start condition can occur only if more than 50 percent of fuel
injectors are without power.

WARNING:

Always refer to safety procedures to reduce possibility of injury. See
FUEL SYSTEM SAFETY PRECAUTIONS.

NOTE:

A break in step numbering sequence occurs at this point. Procedure skips
from step 10) to step 15). No test procedures have been omitted.

Application

Location

Aviator, Blackwood, Econoline, Escape, Excursion, Expedition,

Behind Right Kick Panel

2003 Ford Pickup F150

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

15) Check Fuel Pressure (Natural Gas Vehicles)
Turn ignition switch to OFF position. With scan tool connected to DLC, access FRP PID (fuel pressure).
Turn ignition switch to ON position. Record fuel pressure and compare results with specifications. See
Fig. 167. If fuel pressure is within specification on scan tool and pressure gauge, go to next step. If fuel
pressure is not within specification on scan tool and pressure gauge, go to TEST HB, step 1).

16) Check Injector Signal From Natural Gas Vehicle Module

Turn ignition switch to OFF position. Connect a 12-volt test light between injector signal circuit and
VPWR circuit terminal at fuel injector harness connector. Crank engine while observing test light. If test
light glows dimly while cranking engine, replace PCM and go to step 6). If test light does not glow as
specified, go to TEST HA, step 47).

17) Check PCM Driver To Coils

Turn ignition switch to OFF position. Connect 12-volt test light between B+ and each coil driver circuit at
harness connector. Crank engine while observing test light. Repeat procedure for each coil driver. Test
light should blink brightly, once for each engine revolution. If test light blinks as specified, go to step 6).
If test light does not blink as specified, go to TEST JD, step 1).

TEST B: EEC-V POWER RELAY

Diagnostic Aids

Explorer, Mountaineer, Navigator, Pickup & Ranger
Crown Victoria, Grand Marquis Marauder & Town Car

Left Front Side Of Luggage

Compartment, Behind Lining

Focus

Bottom Of Right "A" Pillar

LS

Behind Left Kick Panel

Mustang

In Left Rear Of Luggage

Compartment

RV Cutaway

On Lower Right Of Steering Column

Sable & Taurus

In Right Side Of Luggage

Compartment. Behind Side Panel

Thunderbird

In Left Side Front Footwell

Windstar

On Right Rear Side Of Vehicle

ZX2

Bottom Of Left "A" Pillar

WARNING:

Always refer to safety procedures to reduce possibility of injury. See
FUEL SYSTEM SAFETY PRECAUTIONS.

NOTE:

After each service or repair procedure has been completed, reconnect all
components. Clear DTCs and repeat QUICK TEST procedures to ensure all EEC-
V systems are working properly and DTCs are no longer present.

2003 Ford Pickup F150

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