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