Ford F150 Pickup. Manual — part 1347

bleed valve on Fuel Filler Neck Venting Kit. Turn ignition on. Using scan tool, enter OUTPUT TEST
MODE. Press "Start" button on scan tool to command all outputs on. Observe and record system pressure
on Fuel Filler Neck Venting Kit Gauge. Press "Stop" button on scan tool. If pressure reading on gauge is
zero psi (zero kPa) when "Start" button is pressed, go to next step. If pressure reading on gauge is more
than zero psi (zero kPa) when "Start" button is pressed, mark fuel tank No. 3 solenoid as "Good" and go
to step 8.

6. Check Power Supply To Fuel Tank No. 3 Solenoid Valve

Turn ignition off. Disconnect tank No. 3 solenoid connector C4147. Connect DVOM between chassis
ground and tank No. 3 solenoid harness connector C4147 terminal No. 1 (Pink/Black wire). See Fig. 6.
Using scan tool, enter OUTPUT TEST MODE. Press "Start" button on scan tool to command all outputs
on. Observe and record voltage reading on DVOM. Press "Stop" button on scan tool. If voltage is equal to
battery voltage when "Start" button is pressed, go to next step. If voltage is less than battery voltage when
"Start" button is pressed, repair Pink/Black wire between tank No. 3 solenoid harness connector and
splice S427 located on left side of luggage compartment for an open and repeat step 5. See ENGINE
PERFORMANCE in appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL.

7. Check Fuel Tank No. 3 Solenoid Valve Ground Circuit For An Open

Turn ignition off. Using DVOM, measure resistance between chassis ground and tank No. 3 solenoid
harness connector C4147 terminal No. 2 (Black wire). If resistance is less than 5 ohms, mark fuel tank
No. 3 solenoid valve "Stuck Closed". A NEW solenoid valve will be installed after completing
diagnostics. Go to next step. If resistance is 5 ohms or more, repair open in Black wire between fuel tank
No. 3 solenoid valve and ground G400 located center rear of luggage compartment and repeat step 5. See
ENGINE PERFORMANCE in appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL.

8. Check Fuel Tank No. 2 Solenoid Valve

Turn ignition off. Disconnect tank No. 3 solenoid valve connector C4147. Open manual bleed valve on
Fuel Filler Neck Venting Kit for 60 seconds, then close manual bleed valve on Fuel Filler Neck Venting
Kit. Install Electrical Harness for Venting Tanks (134-00120) between male and female halves of upper
tank assembly harness connector C421. See Fig. 5. Turn ignition on. Using scan tool, enter OUTPUT
TEST MODE. Hold Electrical Harness for Venting Tanks to tank No. 2 position. Press "Start" button on
scan tool to command all outputs on. Observe and record system pressure on Fuel Filler Neck Venting
Kit Gauge. Press "Stop" button on scan tool. If pressure reading on gauge is zero psi (zero kPa) when
"Start" button is pressed, mark fuel tank No. 2 solenoid valve as "May Be Stuck Closed" and go to next
step. If pressure reading on gauge is more than zero psi (zero kPa) when "Start" button is pressed, mark
fuel tank No. 2 solenoid valve as "Good" and go to next step.

NOTE:

This procedure will supply power to fuel tank solenoid valve for
approximately 30-60 seconds. If time expires, cycle "Start/Stop" button on
scan tool to restore power.

NOTE:

Battery must be fully charged to carry out solenoid valve diagnostics. This
procedure will supply power to fuel tank solenoid valve for approximately
30-60 seconds. If time expires, cycle "Start/Stop" button on scan tool to
restore power.

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE System & Component Testing - CNG

9. Check Fuel Tank No. 1 Solenoid Valve

Ensure Electrical Harness for Venting Tanks is connected to upper fuel tank rack harness connector
C421. Open manual bleed valve on Fuel Filler Neck Venting Kit for 60 seconds, then close manual bleed
valve on Fuel Filler Neck Venting Kit. Using scan tool, enter OUTPUT TEST MODE. Switch Electrical
Harness for Venting Tanks tool to tank No. 1 position. Press "Start" button on scan tool to command all
outputs on. Observe and record system pressure on Fuel Filler Neck Venting Kit Gauge. Press "Stop"
button on scan tool. If pressure reading on gauge is zero psi (zero kPa) when "Start" button is pressed,
mark fuel tank No. 1 solenoid valve as "May Be Stuck Closed" and go to next step. If pressure reading on
gauge is more than zero psi (zero kPa) when "Start" button is pressed, mark fuel tank No. 1 solenoid
valve "Good". To complete diagnostics, install a new solenoid valve if solenoid valve is marked "Stuck
Closed". If fuel tank No. 2 solenoid valve is marked "May Be Stuck Closed", go to next step. If all fuel
tank solenoid valves were marked "Good", diagnostics are complete. Restore vehicle and test system for
normal operation.

10. Check Upper & Rear Tank Rack Ground Circuit

Turn ignition off. Disconnect and remove Electrical Harness for Venting Tanks from upper and rear tank
rack assembly harness connector C421. Open manual bleed valve on Fuel Filter Neck Venting Kit and
vent system pressure to zero psi (zero kPa). Close manual bleed valve on Fuel Filter Neck Venting Kit.
Remove upper and rear fuel tank rack assemblies. Remove upper and rear fuel tank rack assembly vent
boxes. Disconnect tank No. 1 solenoid valve connector C4129, tank No. 2 solenoid valve connector
C4122 and tank No. 5 solenoid valve connector C4204 (if equipped). With upper and rear fuel tank rack
assemblies removed, measure resistance between chassis ground and fuel tanks No. 1, 2 and 5 solenoid
valve harness connector terminal No. 2 (Black wire). See Fig. 6. If each resistance is less than 5 ohms, go
to next step. If any resistance is 5 ohms or more, repair open in affected circuit and go to next step. See
ENGINE PERFORMANCE in appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL.

11. Check Upper & Rear Tank Rack Power Circuit

Ensure ignition is off. Using DVOM, measure resistance of Pink/Black wire between Inertia Fuel Shutoff
(IFS) switch harness connector C392 and fuel tanks No. 1, 2 and 5 solenoid valve harness connector
terminal No. 1. If each resistance is less than 5 ohms, go to next step. If any resistance is 5 ohms or more,
repair open in affected circuit between IFS and appropriate solenoid valve. See ENGINE
PERFORMANCE in appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Reinstall
complete upper and rear tank rack assemblies and vent boxes and repeat step 8.

12. Check Upper Fuel Tank Rack Assembly Manual Lock-Down Jackscrews

NOTE:

This procedure will supply power to fuel tank solenoid valve for
approximately 30-60 seconds. If time expires, cycle "Start/Stop" button on
scan tool to restore power.

NOTE:

At this point in the diagnostics, it is necessary to access upper and rear
fuel tank rack harness connections located behind tank rack vent boxes.
To access and remove upper and rear tank rack vent boxes, it is
necessary to remove upper and rear tank rack assemblies. See FUEL
TANKS under FUEL SYSTEMS in REMOVAL & INSTALLATION - CROWN
VICTORIA - CNG article.

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE System & Component Testing - CNG

With upper and rear fuel tank rack assemblies still removed, check fuel tank No. 1 and No. 2 solenoid
valve manual lock-downs. If manual lock-downs are open, install NEW upper fuel tank rack assembly
solenoids if marked "May Be Stuck Closed". Reinstall complete upper tank rack assembly and vent box,
and repeat step 8. If manual lock-downs are not open, reinstall upper and rear tank rack assemblies
without vent boxes, reconnect all fuel lines and go to next step.

13. Check Fuel Tank No. 2 Solenoid Valve Manual Lock-Down Jackscrew

Open fuel tank No. 2 solenoid valve manual lock-down jackscrew. Open bleed valve on Fuel Filler Neck
Venting Kit for 60 seconds, then close bleed valve. Observe system pressure on Fuel Filler Neck Venting
Kit Gauge. If pressure on gauge is zero psi (zero kPa), mark fuel tank No. 2 solenoid valve "Good" and
go to next step. If pressure on gauge is more than zero psi (zero kPa), mark fuel tank No. 2 solenoid valve
"Stuck Open" and go to next step.

14. Check Fuel Tank No. 1 Solenoid Valve Manual Lock-Down Jackscrew

Tighten manual lock-down jackscrew on fuel tank No. 2 solenoid valve to 62-79 INCH lbs. (7-9 N.m).
Open fuel tank No. 1 solenoid valve manual lock-down jackscrew. Open bleed valve on Fuel Filler Neck
Venting Kit for 60 seconds, then close bleed valve. Observe system pressure on Fuel Filler Neck Venting
Kit Gauge. If system pressure on Fuel Filler Neck Venting Kit Gauge is zero psi (zero kPa), mark fuel
tank No. 1 solenoid valve "Good" and repeat step 8 to retest upper tank rack. If pressure on gauge is more
than zero psi (zero kPa), mark fuel tank No. 1 solenoid valve "Stuck Open". Replace upper fuel tank rack
assembly solenoid valves if marked "Stuck Open" and go to step 8.

15. Check All Solenoid Power Circuits For A Short To B+

Turn ignition off. Using DVOM, measure voltage between chassis ground and terminal No. 1 (Pink/Black
wire) at fuel tank No. 3 solenoid harness connector C4147 and fuel tank No. 4 solenoid harness connector
C4148. Using DVOM, measure voltage between chassis ground and terminal No. 1 (Pink/Black wire) at
fuel tank No. 1 solenoid harness connector C4129 and fuel tank No. 2 solenoid harness connector C4122.
If equipped with a 5th CNG fuel tank, measure voltage between chassis ground and Pink/Black wire at
rear fuel tank rack assembly harness connector C4204. If battery voltage is present at any harness
connector, repair short to battery voltage on affected circuit. See ENGINE PERFORMANCE in
appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Repeat step 1. If battery voltage
is not present at any harness connector, go to next step.

16. Isolate Upper & Lower Tank Rack Assemblies

NOTE:

Ensure bleed valve on Fuel Filler Neck Venting Kit is closed before
proceeding with this step.

NOTE:

Crown Victoria models may be equipped with a 5th additional CNG fuel
tank located in luggage compartment on rear rack assembly.

NOTE:

At this point in the diagnostics, it is necessary to remove rear tank rack
assembly. See FUEL TANKS under FUEL SYSTEMS in REMOVAL &
INSTALLATION - CROWN VICTORIA - NGV article.

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE System & Component Testing - CNG

Tighten manual lock-down jackscrew on fuel tanks No. 3 and 4 solenoid valves to 62-79 INCH lbs. (7-9
N.m). Open manual bleed valve on Fuel Filler Neck Venting Kit for 60 seconds, then close manual bleed
valve. Observe system pressure on Fuel Filler Neck Venting Kit Gauge. If pressure on gauge is zero psi
(zero kPa), go to step 21. If pressure on gauge is more than zero psi (zero kPa), go to next step.

17. Check Fuel Tank No. 1 Power Circuit For Short To B+

Turn ignition off. Ensure manual lock-down jackscrews on fuel tank No. 3 and 4 are still closed from step
16) . Open manual bleed valve on Fuel Filler Neck Venting Kit and vent system pressure to zero psi (zero
kPa). Close manual bleed valve on Fuel Filler Neck Venting Kit. Remove upper tank rack assembly.
Remove upper fuel tank rack assembly vent box. Reinstall upper tank rack assembly without vapor vent
box installed. Reconnect all fuel line connections. Disconnect fuel tank No. 1 solenoid valve harness
connector C4129. Using DVOM, measure voltage between chassis ground and fuel tank No. 1 solenoid
valve harness connector terminal No. 1 (Pink/Black wire). See Fig. 6. If battery voltage is present, repair
short to B+ in Pink/Black wire. See ENGINE PERFORMANCE in appropriate SYSTEM WIRING
DIAGRAMS article in ELECTRICAL. Go to next step. If battery voltage is not present, mark fuel tank
solenoid valve No. 1 as "May Be Stuck Open" and go to next step.

18. Check Fuel Tank No. 2 Power Circuit For Short To B+

Ensure ignition is off. Disconnect fuel tank No. 2 solenoid valve harness connector C4121. Using
DVOM, measure voltage between chassis ground and fuel tank No. 2 solenoid valve harness connector
terminal No. 1 (Pink/Black wire). If battery voltage is present, repair short to B+ in Pink/Black wire. See
ENGINE PERFORMANCE in appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
Repeat step 1. If battery voltage is not present, mark fuel tank No. 2 solenoid valve as "May Be Stuck
Open" and go to next step.

19. Check Fuel Tank No. 2 Solenoid Valve Operation

Ensure manual bleed valve is closed on Fuel Filler Neck Venting Kit. Ensure ignition is off. Reconnect
fuel tank No. 2 solenoid valve harness connector C4121. Tighten fuel tank No. 1 solenoid valve manual
lock-down jackscrew to 62-79 INCH lbs. (7-9 N.m). Connect scan tool to Data Link Connector (DLC).
Turn ignition on. Press "Start" button on scan tool. Using scan tool, enter OUTPUT TEST MODE.
Observe and record system pressure on Fuel Filler Neck Venting Kit Gauge. Press "Stop" button on scan
tool. If pressure on gauge is zero psi (zero kPa) when "Start" button is pressed, mark fuel tank No. 2
solenoid valve "Stuck Open". A NEW solenoid valve will be installed after completing diagnostics. Go to
next step. If pressure on gauge is more than zero psi (zero kPa) when "Start" button is pressed, mark fuel
tank No. 2 solenoid valve "Good" and go to next step.

NOTE:

At this point in the diagnostics, it is necessary to access upper fuel tank
rack harness connections located behind tank rack vent box. To access
and remove upper tank rack vent box, it is necessary to remove upper
tank rack assembly. See FUEL TANKS under FUEL SYSTEMS in
REMOVAL & INSTALLATION - CROWN VICTORIA - CNG article.

NOTE:

This procedure will supply power to fuel tank solenoid valve for
approximately 30-60 seconds. If time expires, cycle "Start/Stop" button on
scan tool to restore power.

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE System & Component Testing - CNG