Ford F150 Pickup. Instruction - part 1346

Visually inspect fuel system for damaged fuel tanks, solenoids, fuel lines/hoses, fuses, relays and loose or 
corroded connectors. If any faults are indicated, repair as necessary. If no faults are indicated and system will 
not vent, proceed with TESTING (CROWN VICTORIA), TESTING (ECONOLINE) or TESTING 
(F150) . 

Fig. 8: Connecting Grounding Cable To Fuel Fill Valve 
Courtesy of FORD MOTOR CO. 

00120) and Instruction Override (134-00050). See Fig. 8-Fig. 10 .

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE System & Component Testing - CNG

  

Fig. 9: Connecting Fuel Filler Neck Venting Kit-To-Fuel Fill Valve 
Courtesy of FORD MOTOR CO. 

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE System & Component Testing - CNG

  

Fig. 10: Identifying Fuel Tank Solenoid Components 
Courtesy of FORD MOTOR CO. 

Testing (Crown Victoria) 

1. Check Fuel System Solenoid Operation 

Turn ignition off. Connect grounding cable, venting hose assembly and fuel filler neck venting kit to vent 
stack and the fuel fill valve. See Fig. 8 and Fig. 9 . Vent stack installation must be approved by local 
authorities. For additional fuel tank venting information, see FUEL SYSTEM PRESSURE RELEASE 
under FUEL SYSTEMS in REMOVAL & INSTALLATION - CROWN VICTORIA - CNG article. 
Disconnect fuel tank solenoid valve No. 3 connector C4147, fuel tank solenoid valve No. 4 connector 
C4148 and upper tank rack 8-pin connector C421. See Fig. 5 and Fig. 6 . Open instruction back flow valve 
on fuel filler valve. Open bleed valve on vent tool for 60 seconds. Close manual bleed valve on vent tool. 
Observe system pressure on fuel filler neck venting kit gauge. If pressure is zero psi (zero kPa), system 
pressure is correct. However, all solenoid valves must be checked for being "Stuck Closed". Go to next 

NOTE:

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

NOTE:

Battery must be fully charged to perform solenoid diagnostics. Whenever 
connecting vent tool, ensure vent tool bleed valve is closed.

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE System & Component Testing - CNG

  

step. If pressure is more than zero psi (zero kPa), leave connectors disconnected and go to step 15. 

2. Check Fuel Tank No. 4 Solenoid Valve 

Ensure ignition is off. Reconnect fuel tank solenoid valve No. 4 connector C4148. 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 pressure reading was zero psi (zero kPa) 
when "Start" button on scan tool was pressed, go to next step. If pressure was more than zero psi (zero 
kPa) when "Start" button on scan tool was pressed, mark No. 4 solenoid valve "Good" and go to step 5. 

3. Check Power Supply To Fuel Tank No. 4 Solenoid Valve 

Turn ignition off. Disconnect fuel tank solenoid valve No. 4 connector C4148. Connect DVOM between 
chassis ground and harness connector C4148 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 
reading is equal to battery voltage when "Start" button is pressed, go to next step. If voltage reading is 
less than battery voltage when "Start" button is pressed, repair open in Pink/Black wire and repeat step 2. 
See ENGINE PERFORMANCE in appropriate SYSTEM WIRING DIAGRAMS article in 
ELECTRICAL. 

4. Check Fuel Tank No. 4 Solenoid Valve Ground Circuit For An Open 

 
Using DVOM, measure resistance between chassis ground and harness connector C4148 terminal No. 2 
(Black wire). If resistance is less than 5 ohms, mark fuel tank solenoid valve No. 4 "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 solenoid valve No. 4 and ground G400 located 
center rear of luggage compartment and repeat step 2. See ENGINE PERFORMANCE in appropriate 
SYSTEM WIRING DIAGRAMS article in ELECTRICAL. 

5. Check Fuel Tank No. 3 Solenoid Valve 

Reconnect tank No. 3 solenoid connector C4147. Disconnect fuel tank solenoid valve No. 4 connector 
C4148. Open instruction bleed valve on Fuel Filler Neck Venting Kit for 60 seconds, then close manual 

NOTE:

Ensure instruction lock-down jackscrew on fuel tank solenoid valve No. 4 is 
open. 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.

NOTE:

Ensure instruction lock-down jackscrew on fuel tank No. 3 solenoid valve is 
open. 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