Page 194 of 323
When your temporary spare tire is installed
When one of your road tires needs to be replaced with the temporary
spare, the TPMS system will continue to identify an issue to remind you
that the damaged road wheel/tire needs to be repaired and put back on
your vehicle.
To restore the full functionality of the Tire Pressure Monitoring System,
have the damaged road wheel/tire repaired and remounted on your
vehicle. For additional information, refer toChanging tires with TPMS
in this section.
When you believe your system is not operating properly
The main function of the Tire Pressure Monitoring System is to warn you
when your tires need air. It can also warn you in the event the system is
no longer capable of functioning as intended. Please refer to the
following chart for information concerning your Tire Pressure Monitoring
System:
2009 MKS(mks)
Owners Guide (post-2002-fmt)
USA(fus)
Tires, Wheels and Loading
194
Page 195 of 323

Low Tire Pressure
Warning LightPossible cause Customer Action Required
Solid Warning Light Tire(s)
under-inflated1. Check your tire pressure to
ensure tires are properly
inflated; refer toInflating
your tiresin this chapter.
2. After inflating your tires to
the manufacturer’s
recommended inflation
pressure as shown on the Tire
Label (located on the edge of
driver’s door or the B-Pillar),
the vehicle must be driven for
at least two minutes over
20 mph (32 km/h) before the
light will turn OFF.
Spare tire in use Your temporary spare tire is in
use. Repair the damaged road
wheel/tire and reinstall it on
the vehicle to restore system
functionality. For a description
on how the system functions,
refer toWhen your temporary
spare tire is installedin this
section.
TPMS
malfunctionIf your tires are properly
inflated and your spare tire is
not in use and the light
remains ON, have the system
inspected by your authorized
dealer.
2009 MKS(mks)
Owners Guide (post-2002-fmt)
USA(fus)
Tires, Wheels and Loading
195
Page 196 of 323

Low Tire Pressure
Warning LightPossible cause Customer Action Required
Flashing Warning
LightSpare tire in use Your temporary spare tire is in
use. Repair the damaged road
wheel and re-mount it on the
vehicle to restore system
functionality. For a description
of how the system functions
under these conditions, refer to
When your temporary spare
tire is installedin this section.
TPMS
malfunctionIf your tires are properly
inflated and your spare tire is
not in use and the TPMS
warning light still flashes, have
the system inspected by your
authorized dealer.
When inflating your tires
When putting air into your tires (such as at a gas station or in your
garage), the Tire Pressure Monitoring System may not respond
immediately to the air added to your tires.
It may take up to two minutes of driving over 20 mph (32 km/h) for the
light to turn OFF after you have filled your tires to the recommended
inflation pressure.
How temperature affects your tire pressure
The Tire Pressure Monitoring System (TPMS) monitors tire pressure in
each pneumatic tire. While driving in a normal manner, a typical
passenger tire inflation pressure may increase approximately 2 to 4 psi
(14 to 28 kPa) from a cold start situation. If the vehicle is stationary
over night with the outside temperature significantly lower than the
daytime temperature, the tire pressure may decrease approximately 3 psi
(20.7 kPa) for a drop of 30° F (16.6°C) in ambient temperature. This
lower pressure value may be detected by the TPMS as being significantly
lower than the recommended inflation pressure and activate the TPMS
warning for low tire pressure. If the low tire pressure warning light is
ON, visually check each tire to verify that no tire is flat. (If one or more
tires are flat, repair as necessary.) Check air pressure in the road tires. If
2009 MKS(mks)
Owners Guide (post-2002-fmt)
USA(fus)
Tires, Wheels and Loading
196
Page 197 of 323

any tire is under-inflated, carefully drive the vehicle to the nearest
location where air can be added to the tires. Inflate all the tires to the
recommended inflation pressure.
SNOW TIRES AND CHAINS
WARNING:Snow tires must be the same size, load index, speed
rating as those originally provided by Ford. Use of any tire or
wheel not recommended by Ford can affect the safety and
performance of your vehicle, which could result in an increased risk of
loss of vehicle control, vehicle rollover, personal injury and death.
Additionally, the use of non-recommended tires and wheels could
cause steering, suspension, axle or transfer case/power transfer unit
failure.
The tires on your vehicle have all-weather treads to provide traction in
rain and snow. However, in some climates, you may need to use snow
tires and chains. If you need to use chains, it is recommended that steel
wheels (of the same size and specifications) be used, as chains may chip
aluminum wheels.
Follow these guidelines when using snow tires and chains:
•Use only SAE class “S” cables or equivalent on P235/55R18 tires on
the front tires only. SAE class “S” chains or other conventional link
chains may cause damage to the vehicles wheel house and/or body.
Use of optional spike spider type traction devices or equivalent is also
acceptable.
•Do not install tire chains, cables, or optional traction devices on the
rear tires. This could cause damage to the vehicle’s wheel house or
body.
•Do not use tire chains, cables, or optional traction devices with
optional P255/45R19 or 245/45R20 tires.
•Install tire cables securely, verifying that the tire cables do not touch
any wiring, brake lines or fuel lines.
•Drive cautiously. If you hear the cables rub or bang against your
vehicle, stop and re-tighten the cables. If this does not work, remove
the cables to prevent damage to your vehicle.
•If possible, avoid fully loading your vehicle.
•Remove the tire cables when they are no longer needed. Do not use
tire cables on dry roads.
2009 MKS(mks)
Owners Guide (post-2002-fmt)
USA(fus)
Tires, Wheels and Loading
197
Page 198 of 323

•The suspension insulation and bumpers will help prevent vehicle
damage. Do not remove these components from your vehicle when
using snow tires and chains.
•Do not exceed 30 mph (48 km/h) with tire cables on your vehicle.
VEHICLE LOADING – WITH AND WITHOUT A TRAILER
This section will guide you in the proper loading of your vehicle and/or
trailer, to keep your loaded vehicle weight within its design rating
capability, with or without a trailer. Properly loading your vehicle will
provide maximum return of vehicle design performance. Before loading
your vehicle, familiarize yourself with the following terms for determining
your vehicle’s weight ratings, with or without a trailer, from the vehicle’s
Tire Label or Safety Compliance Certification Label:
Base Curb Weight– is the weight of the vehicle including a full tank of
fuel and all standard equipment. It does not include passengers, cargo, or
optional equipment.
Vehicle Curb Weight– is the weight of your new vehicle when you
picked it up from your authorized dealer plus any aftermarket
equipment.
2009 MKS(mks)
Owners Guide (post-2002-fmt)
USA(fus)
Tires, Wheels and Loading
198
Page 199 of 323

Payload– is the combined weight of cargo and passengers that the
vehicle is carrying. The maximum payload for your vehicle can be found
on the Tire Label on the B-Pillar or the edge of the driver’s door
(vehicles exported outside the US and Canada may not have a Tire
Label). Look for“THE COMBINED WEIGHT OF OCCUPANTS AND
CARGO SHOULD NEVER EXCEED XXX kg OR XXX lb.”for
maximum payload. The payload listed on the Tire Label is the maximum
payload for the vehicle as built by the assembly plant. If any aftermarket
or authorized-dealer installed equipment has been installed on the
vehicle, the weight of the equipment must be subtracted from the
payload listed on the Tire Label in order to determine the new payload.
WARNING:The appropriate loading capacity of your vehicle can
be limited either by volume capacity (how much space is
available) or by payload capacity (how much weight the vehicle should
carry). Once you have reached the maximum payload of your vehicle,
do not add more cargo, even if there is space available. Overloading or
improperly loading your vehicle can contribute to loss of vehicle
control and vehicle rollover.
2009 MKS(mks)
Owners Guide (post-2002-fmt)
USA(fus)
Tires, Wheels and Loading
199
Page 200 of 323
Example only:
Cargo Weight– includes all weight added to the Base Curb Weight,
including cargo and optional equipment. When towing, trailer tongue load
weight is also part of cargo weight.
GAW (Gross Axle Weight)– is the total weight placed on each axle
(front and rear) – including vehicle curb weight and all payload.
2009 MKS(mks)
Owners Guide (post-2002-fmt)
USA(fus)
Tires, Wheels and Loading
200
Page 201 of 323
GAWR (Gross Axle Weight Rating)– is the maximum allowable
weight that can be carried by a single axle (front or rear).These
numbers are shown on the Safety Compliance Certification Label
located on the B-Pillar or the edge of the driver’s door. The total
load on each axle must never exceed its GAWR.
Note:For trailer towing information refer toTrailer towingfound in
this chapter or theRV and Trailer Towing Guideprovided by your
authorized dealer.
GVW (Gross Vehicle Weight)– is the Vehicle Curb Weight + cargo +
passengers.
GVWR (Gross Vehicle Weight
Rating)– is the maximum
allowable weight of the fully loaded
vehicle (including all options,
equipment, passengers and cargo).
The GVWR is shown on the
Safety Compliance Certification
Label located on the B-Pillar or
the edge of the driver’s door.
The GVW must never exceed the
GVWR.
2009 MKS(mks)
Owners Guide (post-2002-fmt)
USA(fus)
Tires, Wheels and Loading
201