2003 Mercury Grand Marquis catalytic converter

Light remains on:
Temporary malfunctions may cause your light to illuminate. Examples
are:
1. The vehicle has run out of fuel.
2. Poor fuel quality or water in the fuel.
3. The fuel cap may not have been properly installed and securely
tightened.
These temporary malfunctions can be corrected by filling the fuel tank
with high quality fuel of the recommended octane and/or properly
installing and securely tightening the fuel cap. After three driving cycles
without these or any other temporary malfunctions present, the light
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 the light remains on, have your vehicle serviced at the first available
opportunity.
Light is blinking:
Engine misfire is occurring which could damage your catalytic converter.
You should drive in a moderate fashion (avoid heavy acceleration and
deceleration) and have your vehicle serviced at the first available
opportunity.
Under engine misfire conditions, excessive exhaust temperatures
could damage the catalytic converter, the fuel system, interior
floor coverings or other vehicle components, possibly causing a fire.
Check fuel cap
Illuminates when the fuel cap is not
installed correctly. Check the fuel
cap for proper installation. When
the fuel filler cap is properly
re-installed, the light(s) will turn off
after a period of normal driving. Continuing to operate the vehicle with
the check fuel cap light on, or a mis-installed fuel cap can activate the
Service Engine Soon/Check Enginewarning light.
It may take a long period of time for the system to detect an
improperly installed fuel filler cap.
For more information, refer toFuel filler capin theMaintenance and
specificationschapter.
CHECK
FUEL
CAP
2003 Grand Marquis(grn)
Owners Guide (post-2002-fmt)
USA English(fus)
Instrument Cluster
11

JUMP STARTING YOUR VEHICLE
The gases around the battery can explode if exposed to flames,
sparks, or lit cigarettes. An explosion could result in injury or
vehicle damage.
Batteries contain sulfuric acid which can burn skin, eyes and
clothing, if contacted.
Do not attempt to push-start your vehicle. Automatic
transmissions do not have push-start capability; also, the
catalytic converter may become damaged.
Preparing your vehicle
When the battery is disconnected or a new battery is installed, the
transmission must relearn its shift strategy. As a result, the transmission
may have firm and/or soft shifts. This operation is considered normal and
will not affect function or durability of the transmission. Over time, the
adaptive learning process will fully update transmission operation.
1.Use only a 12–volt supply to start your vehicle.
2. Do not disconnect the battery of the disabled vehicle as this could
damage the vehicle’s electrical system.
3. Park the booster vehicle close to the hood of the disabled vehicle
making sure the two vehiclesdo nottouch. Set the parking brake on
both vehicles and stay clear of the engine cooling fan and other moving
parts.
4. Check all battery terminals and remove any excessive corrosion before
you attach the battery cables. Ensure that vent caps are tight and level.
5. Turn the heater fan on in both vehicles to protect any electrical
surges. Turn all other accessories off.
2003 Grand Marquis(grn)
Owners Guide (post-2002-fmt)
USA English(fus)
Roadside Emergencies
175

It is important to note the box in the lower left corner of the window
sticker. These numbers represent the Range of L/100 km (MPG)
expected on the vehicle under optimum conditions. Your fuel economy
may vary depending upon the method of operation and conditions.
EMISSION CONTROL SYSTEM
Your vehicle is equipped with various emission control components and a
catalytic converter which will enable your vehicle to comply with
applicable exhaust emission standards. To make sure that the catalytic
converter and other emission control components continue to work
properly:
•Use only the specified fuel listed.
•Avoid running out of fuel.
•Do not turn off the ignition while your vehicle is moving, especially at
high speeds.
•Have the items listed in your scheduled maintenance guide performed
according to the specified schedule.
The scheduled maintenance items listed in the scheduled maintenance
guide are essential to the life and performance of your vehicle and to its
emissions system.
If other than Ford, Motorcraft or Ford-authorized parts are used for
maintenance replacements or for service of components affecting
emission control, such non-Ford parts should be equivalent to genuine
Ford Motor Company parts in performance and durability.
Do not park, idle, or drive your vehicle in dry grass or other dry
ground cover. The emission system heats up the engine
compartment and exhaust system, which can start a fire.
Illumination of the “Check Engine” light, charging system warning light
or the temperature warning light, fluid leaks, strange odors, smoke or
loss of engine power, could indicate that the emission control system is
not working properly.
Exhaust leaks may result in entry of harmful and potentially
lethal fumes into the passenger compartment.
Do not make any unauthorized changes to your vehicle or engine. By
law, vehicle owners and anyone who manufactures, repairs, services,
sells, leases, trades vehicles, or supervises a fleet of vehicles are not
2003 Grand Marquis(grn)
Owners Guide (post-2002-fmt)
USA English(fus)
Maintenance and Specifications
218