Ford F150 Pickup. Instruction - part 1276

BI-FUEL COMPONENT LOCATIONS 

COMPUTERIZED ENGINE CONTROLS 

ALTERNATE FUEL CONTROL MODULE 

Removal & Installation 

Alternate Fuel Control Module (AFCM) is part of compuvalve. See COMPUVALVE under FUEL SYSTEMS.

PROGRAMMING 

COMPUVALVE RESET PROCEDURE 

Compuvalve reset allows long term fuel adaptive strategy to be reset using the ignition switch and the ALT fuel 
switch. Adaptive strategy should be reset after an engine condition has caused the vehicle to run rich or lean for 
an extended period of time or a heated oxygen sensor requires replacement. When a Compuvalve reset is 
performed, adaptive table is reset to original factory values. 

Turn ignition off. Perform the necessary vehicle preparation and visual inspection. Turn ignition on. Cycle the 
ALT fuel switch from ALT to GAS 5 times in 10 seconds. Road test the vehicle in ALT fuel mode for more 
than 5 minutes. 

FUEL SYSTEMS 

FUEL SYSTEM PRECAUTIONS 

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Avoid inhaling propane gas or occupying confined areas containing propane. Propane is heavier than air. 
The heavier gas can displace or push fresh air out of an area. In large quantities, propane can displace 

NOTE:

For component locations, see BI-FUEL COMPONENT LOCATIONS table.

Application

Location

ALT Fuel Switch

On Instrument Panel

Alternate Fuel Control Module

Integral To Compuvalve

Compuvalve

On Top Of Engine

Fuel Pressure Relief Valve

On Fuel Tank

Power Distribution Box

On Left Side Of Engine Compartment

Vaporizer

On Back Of Engine

CAUTION: When battery is disconnected, vehicle computer and memory systems 

may lose memory data. Driveability problems may exist until computer 
systems have completed a relearn cycle. See COMPUTER RELEARN 
PROCEDURES article in GENERAL INFORMATION before disconnecting 
battery.

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE Removal & Installation - F150 Pickup - Bi-Fuel - Gasoline/LPG

  

enough oxygen to make the surrounding air unfit to breathe and possibly cause illness. If a person 
breathes propane gas or air that lacks oxygen due to the presence of propane gas, headache, dizziness, and 
weakness in the extremities can occur. In severe cases, prolonged breathing of propane-fouled air can 
cause suffocation. In the event of illness from inhaling propane gas, move the victim immediately to fresh 
air and contact a physician or medical emergency personnel for artificial respiration or other required 
treatment.  

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Do not needlessly vent propane fuel during service, and do not open the 80% stop-fill valve while a 
vehicle is inside a building. When servicing the fuel system, follow the recommended procedures to shut 
off the fuel tanks and run the engine out of fuel before disconnecting the fuel system components. If the 
fuel tank(s) are being serviced, have the fuel evacuated by trained personnel at a local propane fuel 
station. Liquid propane fuel vaporizes at normal barometric pressure at temperatures above -44°F (-42°
C), and expands to 270 times its volume as a liquid. Unnecessary venting of propane fuel can create fire 
and health hazards which could cause personal injury or death.  

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Be alert for situations that may cause the propane fuel system to vent fuel. These include extremely hot 
days, parking near a space heater, or hoisting a vehicle up near a ceiling heater. Release of propane fuel in 
a confined area through the pressure relief valve could occur. The release of propane fuel in a confined 
area could result in an accumulation of flammable vapors. If fuel is vented near a heat source, a fire or 
explosion could occur.  

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Do not use paint drying ovens for propane fueled vehicles. The heat of paint drying ovens will increase 
the pressure in the fuel tanks. This could cause venting of propane fuel vapor into the oven and result in a 
fire from the heat or sparks in the electrical equipment. If the fuel is confined inside an oven an explosion 
may occur. When refinishing the body panels of a propane fueled vehicle use spot painting and drying 
methods.  

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If a confined area, such as a lubrication pit, has been subjected to propane gas the area should be 
inspected for adequate oxygen levels by a local health department before being entered or personal injury 
or death may occur.  

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The fuel system pressure must be relieved before any component can be removed. The fuel tanks must be 
evacuated prior to tank removal. Removal of components without pressure relief or tank evacuation can 
cause propane fuel to escape into the air and cause injury or death.  

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In high ambient temperatures, such as those experienced in desert locations, the fuel system is designed to 
vent excess fuel vapor pressure. The pressure relief valve will vent fuel and automatically reset itself. 
Observe all precautions when repairing any fuel-related component.  

FUEL SYSTEM PRESSURE RELEASE 

Liquefied Petroleum Gas Fuel Line Venting 

WARNING:

Fuel supply lines remain pressurized after engine shutdown. Ensure no 
open flame of any type is present. Flammable gases may be present and 
ignite, resulting in possible injury. Always release (vent) fuel pressure 
before disconnecting any fuel injection-related component downstream of 
fuel tank shutoff solenoids.

NOTE:

LPG fuel system is designed to vent excess fuel vapor pressure in high ambient 
temperatures. The pressure relief valve will vent fuel and should automatically 

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE Removal & Installation - F150 Pickup - Bi-Fuel - Gasoline/LPG

  

Raise and support vehicle on hoist. Remove the fuel tank shield. Close fuel tank valve. Residual fuel line 
pressure will be present. Set ALT/GAS switch to ALT position. Start and run vehicle until ALT/GAS switch 
indicator goes off. To pressurize system, slowly open fuel tank valve and reverse procedure. 

Liquefied Petroleum Gas Fuel Tank Evacuating 

1. Relieve the propane fuel system pressure. See LIQUEFIED PETROLEUM GAS FUEL LINE 

VENTING . 

2. Slowly disconnect the fuel line. Connect a propane hose to the fuel tank valve and to an approved holding 

tank supply valve.  

3. Slowly open the supply valve on the fuel tank and the holding tank. If the supply valve is opened too fast, 

the excess flow valve will close.  

4. Open the fixed liquid level valve on the holding tank. Fully close the supply valves on the fuel and the 

holding tank if no liquid appears. If liquid is present continue to evacuate the fuel tank. After vehicle tank 
is evacuated, fully close the supply valves on the fuel and the holding tank. Disconnect the propane hose 
from both tanks.  

COMPUVALVE 

Removal & Installation 

1. Release LPG fuel pressure. See LIQUEFIED PETROLEUM GAS FUEL LINE VENTING under 

FUEL SYSTEM PRESSURE RELEASE. Disconnect negative battery cable. Drain engine cooling 
system. Remove the air cleaner and outlet tube as an assembly. Remove 2 bolts and disconnect main 
harness from compuvalve. See Fig. 2 . Disconnect the ground and modular electrical connectors. See Fig. 
3 . Disconnect the ground strap. See Fig. 4 .  

2. Disconnect the fuel lines. See Fig. 5 . Disconnect the coolant hoses and one vacuum line. See Fig. 6 . 

Disconnect the connector. See Fig. 7 . Remove the 3 bolts and the compuvalve. See Fig. 8 .  

3. To install, reverse removal procedure. Use NEW copper washers only. The reuse of copper washers may 

cause sealing issues and liquid propane gas leaks in the engine compartment.  

reset itself.

NOTE:

LPG fuel system is designed to vent excess fuel vapor pressure in high ambient 
temperatures. The pressure relief valve will vent fuel and should automatically 
reset itself.

NOTE:

If fuel tank(s) are being serviced, perform following procedure or have tank(s) 
evacuated by trained personnel at a propane fueling station.

NOTE:

This step must be carried out outside, and according to local regulations.

NOTE:

See FUEL SYSTEM PRECAUTIONS .

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE Removal & Installation - F150 Pickup - Bi-Fuel - Gasoline/LPG

  

4. Pressurize LPG fuel system and perform leak test. See LEAK TEST - ALL BI-FUEL VEHICLES 

under FUEL SYSTEMS in SYSTEM & COMPONENT TESTING - BI-FUEL - GASOLINE/CNG 
article. Fill and bleed the cooling system.  

Fig. 2: Locating Compuvalve Main Harness Bolts 
Courtesy of FORD MOTOR CO. 

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE Removal & Installation - F150 Pickup - Bi-Fuel - Gasoline/LPG