Page 79 of 312

DTE is calculated using a running average fuel economy, which is based
on your recent driving history of 500 miles (800 km). This value is not
the same as the average fuel economy display. The running average fuel
economy is reinitialized to a factory default value if the battery is
disconnected.
Average fuel economy (AFE)
Select this function from the INFO
menu to display your average fuel
economy in miles/gallon or liters/100
km.
If you calculate your average fuel
economy by dividing gallons of fuel
used by 100 miles traveled (kilometers traveled by liters used), your
figure may be different than displayed for the following reasons:
•Your vehicle was not perfectly level during fill-up
•Differences in the automatic shut-off points on the fuel pumps at
service stations
•Variations in top-off procedure from one fill-up to another
•Rounding of the displayed values to the nearest 0.1 gallon (liter)
1. Drive the vehicle at least 5 miles (8 km) with the speed control
system engaged to display a stabilized average.
2. Record the highway fuel economy for future reference.
It is important to press the RESET control after setting the speed
control to get accurate highway fuel economy readings.
Trip elapsed drive time
Select this function from the INFO
menu to display a timer.
To operate the Trip Elapsed Drive
Time perform the following:
1. Press and release RESET in order
to start the timer.
2. Press and release RESET to pause the timer.
3. Press and hold RESET for 2 seconds in order to reset the timer.
REVIEW COPY
2005 F150(f12), Owners Guide (post-2002-fmt)(own2002),
Market:USA_English(fus)
Driver Controls
79
Page 270 of 312

How fail-safe cooling works
If the engine begins to overheat:
•The engine coolant temperature
gauge will move to the red (hot)
area.
•The mini message center (if
equipped) will indicate“Check
Gauges”, refer toWarning Lights
and Chimesin theInstrument Clusterchapter.
•The message center (if equipped) will indicate a system warning, refer
toMessage Centerin theDriver Controlschapter.
•TheService engine soonindicator light will illuminate.
If the engine reaches a preset over-temperature condition, the engine
will automatically switch to alternating cylinder operation. Each disabled
cylinder acts as an air pump and cools the engine.
When this occurs the vehicle will still operate. However:
•The engine power will be limited.
•The air conditioning system will be disabled.
Continued operation will increase the engine temperature:
•The engine will completely shut down.
•Steering and braking effort will increase.
Once the engine temperature cools, the engine can be re-started. Take
your vehicle to a service facility as soon as possible to minimize engine
damage.
When fail-safe mode is activated
You have limited engine power when in the fail-safe mode, so drive the
vehicle with caution. The vehicle will not be able to maintain high speed
operation and the engine will run rough. Remember that the engine is
capable of completely shutting down automatically to prevent engine
damage, therefore:
1. Pull off the road as soon as safely possible and turn off the engine.
2. Arrange for the vehicle to be taken to a service facility.
3. If this is not possible, wait a short period for the engine to cool.
4. Check the coolant level and replenish if low.
REVIEW COPY
2005 F150(f12), Owners Guide (post-2002-fmt)(own2002),
Market:USA_English(fus)
Maintenance and Specifications
270
Page 280 of 312

the Vehicle Emission Control Information Decal located on or near the
engine. This decal identifies engine displacement and gives some tune up
specifications.
Please consult yourWarranty Guidefor complete emission warranty
information.
On board diagnostics (OBD-II)
Your vehicle is equipped with a computer that monitors the engine’s
emission control system. This system is commonly known as the On
Board Diagnostics System (OBD-II). This OBD-II system protects the
environment by ensuring that your vehicle continues to meet
government emission standards. The OBD-II system also assists the
service technician in properly servicing your vehicle. When theCheck
engine/Service engine soonlight illuminates, the OBD-II system has
detected a malfunction. Temporary malfunctions may cause yourCheck
engine/Service engine soonlight to illuminate. Examples are:
1. The vehicle has run out of fuel. (The engine may misfire or run
poorly.)
2. Poor fuel quality or water in the fuel.
3. The fuel cap may not have been securely tightened.
These temporary malfunctions can be corrected by filling the fuel tank
with good quality fuel and/or properly tightening the fuel cap. After three
driving cycles without these or any other temporary malfunctions
present, theCheck engine/Service engine soonlight should turn off. (A
driving cycle consists of a cold engine startup followed by mixed
city/highway driving.) No additional vehicle service is required.
If theCheck engine/Service engine soonlight remains on, have your
vehicle serviced at the first available opportunity.
Readiness for Inspection/Maintenance (I/M) testing
In some localities, it may be a legal requirement to pass an I/M test of
the on-board diagnostics system. If yourService engine soonlight is on,
refer to the description in theWarning lights and chimessection of the
Instrument Clusterchapter. Your vehicle may not pass the I/M test with
theService engine soonlight on.
If the vehicle’s powertrain system or its battery has just been serviced,
the on-board diagnostics system is reset to a“not ready for I/M test”
condition. To ready the on-board diagnostics system for I/M testing, a
minimum of 30 minutes of city and highway driving is necessary as
described below:
REVIEW COPY
2005 F150(f12), Owners Guide (post-2002-fmt)(own2002),
Market:USA_English(fus)
Maintenance and Specifications
280