Page 2 of 240
Seating and Safety Restraints 86
Seating 86
Safety restraints 90
Air bags 104
Child restraints 111
Driving 123
Starting 123
Brakes 127
Traction control 130
Air suspension 132
Transmission operation 133
Vehicle loading 138
Trailer towing 140
Recreational towing 143
Roadside Emergencies 144
Getting roadside assistance 144
Hazard flasher switch 145
Fuel pump shut-off switch 145
Fuses and relays 146
Changing tires 153
Jump starting 159
Wrecker towing 165
Customer Assistance 166
Reporting safety defects (U.S. only) 174
Cleaning 175
Table of Contents
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Page 8 of 240
These are some of the symbols you may see on your vehicle.
Vehicle Symbol Glossary
Safety Alert
See Owner’s Guide
Fasten Safety BeltAir Bag-Front
Air Bag-SideChild Seat
Child Seat Installation
WarningChild Seat Lower
Anchor
Child Seat Tether
AnchorBrake System
Anti-Lock Brake SystemBrake Fluid -
Non-Petroleum Based
Traction ControlAdvanceTrac
Master Lighting SwitchHazard Warning Flasher
Fog Lamps-FrontFuse Compartment
Fuel Pump ResetWindshield Wash/Wipe
Windshield
Defrost/DemistRear Window
Defrost/Demist
2004 Grand Marquis(grn)
Owners Guide (post-2002-fmt)
USA English(fus)
Introduction
8
Page 132 of 240

It is also important to maintain a proper power steering fluid level in the
power steering fluid reservoir:
•Do not operate the vehicle with a low power steering pump fluid level
(below the MIN mark on the reservoir).
•Some noise is normal during operation. If the noise is excessive, check
for low power steering pump fluid level before seeking service by your
dealer.
•Heavy or uneven steering efforts may be caused by low power steering
pump fluid level. Check for low power steering pump fluid level before
seeking service by your dealer.
•Do not fill the power steering pump reservoir above the MAX mark on
the reservoir, as this may result in leaks from the reservoir.
If the power steering system breaks down (or if the engine is turned
off), you can steer the vehicle manually, but it takes more effort.
If the steering wanders or pulls, check for:
•an improperly inflated tire
•uneven tire wear
•loose or worn suspension components
•loose or worn steering components
•improper steering alignment
Speed sensitive steering
The steering in your vehicle is speed sensitive. At high speeds, steering
assist will decrease to improve steering feel. At lower speeds,
maneuverability will be increased.
If the amount of effort required to steer your vehicle changes while
driving at a constant vehicle speed, have the power steering system
checked by your dealer or a qualified service technician.
AIR SUSPENSION SYSTEM (IF EQUIPPED)
The air suspension system is designed to improve ride, handling and
general vehicle performance during:
•Certain road conditions
•Steering maneuvers
•Braking
•Accelerations
2004 Grand Marquis(grn)
Owners Guide (post-2002-fmt)
USA English(fus)
Driving
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Page 152 of 240
Fuse/Relay
LocationFuse Amp
RatingPower Distribution Box
Description
16—Not used
17—Not used
18—Not used
19 15A* Powertrain Control Module
(PCM), Fuel injectors
20 15A* PCM, HEGOs
21—Not used
22—Not used
23—Not used
24—Not used
101 30A** Ignition switch, Starter motor
solenoid via starter relay, IP fuses
7, 9, 12 and 14
102 50A** Cooling fan (engine)
103 40A** Blower motor
104 40A** Heated backlight relay
105 30A** PCM power relay, Diagnostic
connector, PDB fuses 19 and 20,
A/C clutch relay, Fuel pump
module relay
106 40A** Anti-lock Brake System (ABS)
107—Not used
108—Not used
109–Not used
110–Not used
111–Not used
112 50A** Ignition switch feed to IP fuses 4,
6, 8, 11, 13, 15, 17, 20, 22 and 28
113 50A** Feeds IP fuses 3, 5, 21, 23, 25, 27
114 30A** VAP Steering, Air suspension
compressor, Instrument cluster
2004 Grand Marquis(grn)
Owners Guide (post-2002-fmt)
USA English(fus)
Roadside Emergencies
152
Page 153 of 240

Fuse/Relay
LocationFuse Amp
RatingPower Distribution Box
Description
115 50A** Ignition switch feed to IP fuses 16
and 18
116 30A** Wipers
117–Not used
118 20A** ABS
201 1/2 ISO Horn relay
202 1/2 ISO PCM relay
203 1/2 ISO Fuel pump relay
204 1/2 ISO A/C clutch relay
205 1/2 ISO Traction control switch relay
206—Not used
207—Not used
208 1/2 ISO Moonroof relay
209—Not used
301 Full ISO Blower motor relay
302 Full ISO Starter solenoid relay
303 Full ISO Air suspension relay
304 Full ISO Heated backlight relay
401—Not used
501 Diode PCM
502 Diode A/C clutch
503—Not used
601—Not used
602 20A** Adjustable pedals, Power seat,
Locks, Decklid, Lumbar
* Mini fuse ** Circuit breaker/Maxi fuse
Relays
Relays are located in the power distribution box and should be replaced
by qualified technicians.
CHANGING THE TIRES
If you get a flat tire while driving, do not apply the brake heavily.
Instead, gradually decrease your speed. Hold the steering wheel firmly
and slowly move to a safe place on the side of the road.
2004 Grand Marquis(grn)
Owners Guide (post-2002-fmt)
USA English(fus)
Roadside Emergencies
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Page 195 of 240

What you should know about fail-safe cooling
If the engine coolant supply is depleted, this feature allows the vehicle to
be driven temporarily before incremental component damage is incurred.
The“fail-safe”distance depends on ambient temperatures, vehicle load
and terrain.
How fail-safe cooling works
•Standard cluster
•Optional cluster
If the engine begins to overheat:
•The engine coolant temperature gauge will move to the H (hot) area
(if your vehicle is equipped with analog gauges).
•The engine coolant temperature gauge will illuminate all eight bars
and a tone will sound every five seconds for one minute (if your
vehicle is equipped with digital gauges).
•TheCheck Engineindicator 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.
TEMPH
C
N
O
R
M
H
C
2004 Grand Marquis(grn)
Owners Guide (post-2002-fmt)
USA English(fus)
Maintenance and Specifications
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Page 200 of 240

Octane recommendations
Your vehicle is designed to use
“Regular”unleaded gasoline with
pump (R+M)/2 octane rating of 87.
We do not recommend the use of
gasolines labeled as“Regular”that
are sold with octane ratings of 86 or lower in high altitude areas.
Do not be concerned if your engine sometimes knocks lightly. However, if
it knocks heavily under most driving conditions while you are using fuel
with the recommended octane rating, see your dealer or a qualified
service technician to prevent any engine damage.
Fuel quality
If you are experiencing starting, rough idle or hesitation driveability
problems, try a different brand of unleaded gasoline.“Premium”
unleaded gasoline is not recommended for vehicles designed to use
“Regular”unleaded gasoline because it may cause these problems to
become more pronounced. If the problems persist, see your dealer or a
qualified service technician.
It should not be necessary to add any aftermarket products to your fuel
tank if you continue to use high quality fuel of the recommended octane
rating. Aftermarket products could cause damage to the fuel system.
Repairs to correct the effects of using an aftermarket product in your
fuel may not be covered by your warranty.
Many of the world’s automakers approved the World-wide Fuel Charter
that recommends gasoline specifications to provide improved
performance and emission control system protection for your vehicle.
Gasolines that meet the World-wide Fuel Charter should be used when
available. Ask your fuel supplier about gasolines that meet the
World-wide Fuel Charter.
Cleaner air
Ford endorses the use of reformulated“cleaner-burning”gasolines to
improve air quality.
Running out of fuel
Avoid running out of fuel because this situation may have an adverse
affect on powertrain components.
If you have run out of fuel:
•You may need to cycle the ignition from OFF to ON several times after
refueling, to allow the fuel system to pump the fuel from the tank to
the engine.
87(R+M)/2 METHOD
2004 Grand Marquis(grn)
Owners Guide (post-2002-fmt)
USA English(fus)
Maintenance and Specifications
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Page 218 of 240

Use the recommended cold inflation pressure for optimum tire
performance and wear. Under-inflation or over-inflation may cause
uneven treadwear patterns.
Under-inflation is the most common cause of tire failures and
may result in severe tire cracking, tread separation orblowout,
with unexpected loss of vehicle control and increased risk of injury.
Under-inflation increases sidewall flexing and rolling resistance,
resulting in heat buildup and internal damage to the tire. It also may
result in unnecessary tire stress, irregular wear, loss of vehicle control
and accidents. A tire can lose up to half of its air pressure and not
appear to be flat!
When weather temperature changes occur, tire inflation pressures also
change. A 10°F(6°C) temperature change can cause a corresponding
drop of 1 psi (7 kPa) in inflation pressure. Check your tire pressures
frequently and adjust them to the proper pressure which can be found
on the tire label or certification label.
If you are checking tire pressure when the tire is hot, (i.e. driven more
than 1 mile [1.6 km]), never“bleed”or reduce air pressure. The tires are
hot from driving and it is normal for pressures to increase above
recommended cold pressures. A hot tire at or below recommended cold
inflation pressure could be significantly under-inflated.
To check the pressure in your tire(s):
1. Make sure the tires are cool, meaning they are not hot from driving
even a mile.
Note:If you have to drive a distance to get air for your tire(s), check
and record the tire pressure first and add the appropriate air pressure
when you get to the pump. It is normal for tires to heat up and the air
pressure inside to go up as you drive. Never“bleed”or reduce air
pressure when tires are hot.
2. Remove the cap from the valve on one tire, then firmly press the tire
gauge onto the valve and measure the pressure.
3. Add enough air to reach the recommended air pressure
Note:If you overfill the tire, release air by pushing on the metal stem in
the center of the valve. Then recheck the pressure with your tire gauge.
4. Replace the valve cap.
5. Repeat this procedure for each tire, including the spare.
2004 Grand Marquis(grn)
Owners Guide (post-2002-fmt)
USA English(fus)
Maintenance and Specifications
218