Ford F150 Pickup. Instruction — part 1348

20. Check Fuel Tank No. 1 Solenoid Valve Operation

Turn ignition off. Open instruction 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. Open fuel tank No. 1
solenoid valve manual lock-down jackscrew. Close fuel tank No. 2 solenoid valve manual lock-down
jackscrew to 62-79 INCH lbs. (7-9 N.m). Disconnect fuel tank No. 2 solenoid valve harness connector
C4121. Reconnect fuel tank No. 1 solenoid valve harness connector C4129. Turn ignition on. Using scan
tool, enter OUTPUT TEST MODE. Press "Start" button on scan tool. Observe 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. 1 solenoid valve "Stuck Open". Replace any
upper tank rack assembly valve if marked "Stuck Open" and go to next step. If pressure on gauge is more
than zero psi (zero kPa) when "Start" button is pressed, mark fuel tank No. 1 solenoid valve "Good" and
go to next step.

21. Check Fuel Tank No. 3 Solenoid Valve For "Stuck Open" Condition

Turn ignition off. Open instruction lock-down jackscrew on fuel tank No. 3 solenoid valve. Ensure manual
lock-down jackscrew on fuel tank solenoid valve No. 4 is still closed from step 16) . 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), mark fuel
tank No. 3 solenoid valve "Good" and go to next step. If pressure on gauge is more than zero psi (zero
kPa), mark fuel tank No. 3 solenoid valve "Stuck Open". A NEW solenoid valve will be installed when
diagnostics are complete. Go to next step.

22. Check Fuel Tank No. 4 Solenoid For "Stuck Open" Condition

Ensure ignition is off. Close fuel tank No. 3 solenoid valve instruction lock-down jackscrew. Tighten
jackscrew to 62-79 INCH lbs. (7-9 N.m). 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.
Open manual lock-down jackscrew on fuel tank solenoid valve No. 4. Open manual bleed valve on Fuel
Filler Neck Venting Kit for 60 seconds, then close manual bleed valve. Observe and record system
pressure on Fuel Filler Neck Venting Kit Gauge. If pressure on gauge is zero psi (zero kPa), mark fuel
tank solenoid valve No. 4 "Good". If No. 3 solenoid valve is marked "Stuck Open", replace solenoid
valve at this time and go to next step. If pressure on gauge is more than zero psi (zero kPa), fuel tank
solenoid valve No. 4 is stuck open. Replace fuel tank solenoid valve No. 4 and go to next step.

23. Check Fuel Tank No. 5 Solenoid Valve

Ensure ignition is off. Install Electrical Harness for Venting Tanks to rear fuel tank rack harness
connector C421. See Fig. 5. Open instruction bleed valve on Fuel Filler Neck Venting Kit for 60 seconds,
then close manual bleed valve. Turn ignition on. Using scan tool, enter OUTPUT TEST MODE. Switch

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:

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

Electrical Harness for Venting Tanks tool to tank No. 1 position. Press "Start" button on scan tool.
Observe 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, fuel tank No. 5 solenoid valve
"May Be Stuck Closed". Go to next step. If pressure on gauge is more than zero psi (zero kPa) when
"Start" button is pressed, mark fuel tank No. 5 solenoid valve "Good" and go to next step.

24. Check Rear Fuel Tank Rack Assembly Instruction Lock-Down Jackscrews

With rear fuel tank rack assembly installed without vent box, check fuel tank No. 5 solenoid valve
instruction lock-down jackscrews. If manual lock-down jackscrews are not open, go to next step. If manual
lock-down jackscrews are open, replace any solenoids which are marked "Stuck Closed". If fuel tank No.
5 solenoid valve is marked as "May Be Stuck Closed", replace solenoid at this time. Restore vehicle and
retest system for normal operation.

25. Check Fuel Tank No. 5 Solenoid Valve Instruction Lock-Down Jackscrews

Open fuel tank No. 5 solenoid valve instruction 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), go to step 23.
If system pressure on Fuel Filler Neck Venting Kit Gauge is more than zero psi (zero kPa), mark fuel tank
No. 5 solenoid valve "Stuck Open" and go step 15.

26. Check Fuel Tank No. 5 Solenoid Valve Operation

Ensure ignition is off. Leave Electrical Harness for Venting Tanks tool used in step 23) connected to
upper fuel tank rack harness connector C421. Open instruction bleed valve on Fuel Filler Neck Venting Kit
for 60 seconds, then close manual bleed valve on Fuel Filler Neck Venting Kit. Turn ignition on. 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. 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. 5 solenoid valve as "Does Not Operate". Replace any
solenoids marked as "Stuck Closed" at this time. Restore vehicle and retest system for normal operation.
If pressure on gauge is more than zero psi (zero kPa) when "Start" button is pressed, mark fuel tank No. 5
solenoid valve "Good". To complete diagnostics, replace any solenoid valve which is marked "Stuck
Closed". If all solenoid valves are marked "Good", diagnostics are complete. Restore vehicle and retest
system for normal operation.

Testing (Econoline)

1. Check Midship Fuel Tank For An Open Solenoid Valve

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 diagnostics. Ensure
instruction lock-down valve jackscrew on midship fuel tank solenoid valve is
in open (full counterclockwise) position.

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE System & Component Testing - CNG

Turn ignition off. Connect grounding cable, venting hose assembly and fuel filler neck venting kit to vent
stack and fuel fill valve assembly. See Fig. 8 and Fig. 9 . Vent stack installation must be approved by
local authorities. For additional fuel tank venting information, see COMPRESSED NATURAL GAS
FUEL TANK EVACUATING under FUEL SYSTEM PRESSURE RELEASE in REMOVAL &
INSTALLATION - ECONOLINE - CNG article. Close instruction lock-down valve jackscrews on forward
and rear aft-axle fuel tank solenoid valves and extended range fuel tank solenoid valve, if equipped. See
Fig. 10. Tighten jackscrews to 62-79 INCH lbs. (7-9 N.m). Open manual backflow valve on fuel filler
valve. Open manual bleed valve on fuel filler neck venting kit for 60 seconds. Close manual bleed valve
on fuel filler neck venting kit. Observe and record system pressure on fuel filler neck venting kit gauge. If
pressure on gauge is zero psi (zero kPa), go to step 3. If pressure on gauge is more then zero psi (zero
kPa), go to next step.

2. Check Midship Fuel Tank Solenoid Valve Power Circuit For A Short To Voltage

Ensure ignition is off. Disconnect midship fuel tank solenoid valve connector C3132. Using DVOM,
measure voltage between chassis ground and midship fuel tank solenoid valve harness connector C3132
terminal No. 1 (Pink/Black wire). See Fig. 6. Proceed as follows:

z

If voltage is 10 volts or more and vehicle is not equipped with aft-axle fuel tanks, repair short to
power Pink/Black wire. See ENGINE PERFORMANCE in appropriate SYSTEM WIRING
DIAGRAMS article in ELECTRICAL. Retest system for normal operation.

z

If voltage is 10 volts or more and vehicle is equipped with aft-axle fuel tanks, repair short to power
Pink/Black wire and go to step 6. See ENGINE PERFORMANCE in appropriate SYSTEM
WIRING DIAGRAMS article in ELECTRICAL.

z

If voltage is less than 10 volts and vehicle is not equipped with aft-axle fuel tanks, replace midship
fuel tank solenoid valve and retest system for normal operation.

z

If voltage is less than 10 volts and vehicle is equipped with aft-axle fuel tanks, mark fuel tank
solenoid valve as "Stuck Open". Go to step 6.

3. Check Midship Fuel Tank Solenoid Valve Operation

Ensure ignition is off. Reconnect midship fuel tank solenoid valve harness connector C3132. Connect
scan tool to Data Link Connector (DLC). 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 system pressure reading is zero
psi (zero kPa) when "Start" button is pressed, go to next step. If system pressure reading is more than zero
psi (zero kPa) when "Start" button is pressed, mark midship fuel tank solenoid valve as "Functions
Normally". If vehicle is equipped with aft-axle fuel tanks, go to step 6.

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:

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

4. Check Midship Fuel Tank Solenoid Valve Power Circuit For An Open

Ensure ignition is off. Disconnect midship fuel tank solenoid valve harness connector C3132. Connect
DVOM between chassis ground and midship fuel tank solenoid valve harness connector C3132 terminal
No. 1 (Pink/Black wire). See Fig. 6. Turn ignition on. 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 more than 10 volts, go to next step. If voltage is 10
volts or less, repair open in Pink/Black wire and retest system for normal operation. See ENGINE
PERFORMANCE in appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If vehicle is
equipped with aft-axle fuel tanks, go to step 6.

5. Check Midship Fuel Tank Solenoid Valve Ground Circuit For An Open

Turn ignition off. Using DVOM, measure resistance between chassis ground and midship fuel tank
solenoid valve harness connector C3132 terminal No. 2 (Black wire). Proceed as follows:

z

If resistance is 5 ohms or more and vehicle is not equipped with aft-axle fuel tanks, repair open in
Black wire. See ENGINE PERFORMANCE in appropriate SYSTEM WIRING DIAGRAMS
article in ELECTRICAL. Retest system for normal operation.

z

If resistance is 5 ohms or more and vehicle is equipped with aft-axle fuel tanks, repair open in
Black wire and go to next step. See ENGINE PERFORMANCE in appropriate SYSTEM WIRING
DIAGRAMS article in ELECTRICAL.

z

If resistance is less than 5 ohms and vehicle is not equipped with aft-axle fuel tanks, replace
midship fuel tank solenoid valve and retest system for normal operation.

z

If resistance is less than 5 ohms and vehicle is equipped with aft-axle fuel tanks, go to next step.

6. Check Rear Aft-Axle Fuel Tank For An Open Solenoid Valve

Reconnect midship fuel tank solenoid valve harness connector C3132. Close instruction lock-down valve
jackscrew on midship fuel tank solenoid valve. See Fig. 10. Tighten jackscrew to 62-79 INCH lbs. (7-9
N.m). Open manual lock-down valve jackscrew on rear aft-axle fuel tank solenoid valve. Open manual
bleed valve on fuel filler neck venting kit for 60 seconds. Close manual bleed valve on fuel filler neck
venting kit. Observe system pressure on fuel filler neck venting kit gauge. If pressure reading on gauge is
zero psi (zero kPa), go to step 8. If pressure reading on gauge is more than zero psi (zero kPa), go to next
step.

7. Check Rear Aft-Axle Fuel Tank Solenoid Valve Power Circuit For A Short To Voltage

Ensure ignition is off. Disconnect rear aft-axle fuel tank solenoid valve harness connector C3126. Using
DVOM, measure voltage between chassis ground and rear aft-axle fuel tank solenoid valve harness
connector C3126 terminal No. 1 (Pink/Black wire). See Fig. 6. If voltage is 10 volts or more, repair short
to voltage in Pink/Black wire. See ENGINE PERFORMANCE in appropriate SYSTEM WIRING
DIAGRAMS article in ELECTRICAL. Retest system for normal operation and go to step

11

. If voltage is

less than 10 volts, mark rear aft-axle fuel tank solenoid valve as "Stuck Open". A NEW solenoid valve
will be installed after diagnostics have been completed. Go to step 11.

NOTE:

Ensure instruction lock-down valve jackscrew on rear aft-axle fuel tank
solenoid valve is in open (full counterclockwise) position.

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE System & Component Testing - CNG