trailer JEEP GRAND CHEROKEE 2007 WK / 3.G SRT Owners Manual

12. Tire Pressure Monitoring Telltale Light
Each tire, including the spare (if provided),
should be checked monthly when cold and
inflated to the inflation pressure recommended
by the vehicle manufacturer on the vehicle
placard or tire inflation pressure label. (If your vehicle
has tires of a different size than the size indicated on the
vehicle placard or tire inflation pressure label, you should
determine the proper tire inflation pressure for those
tires.)
As an added safety feature, your vehicle has been
equipped with a tire pressure monitoring system (TPMS)
that illuminates a low tire pressure telltale when one or
more of your tires is significantly under-inflated. Accord-
ingly, when the low tire pressure telltale illuminates, you
should stop and check your tires as soon as possible, and
inflate them to the proper pressure. Driving on a signifi-
cantly under-inflated tire causes the tire to overheat andcan lead to tire failure. Under-inflation also reduces fuel
efficiency and tire tread life, and may affect the vehicle's
handling and stopping ability.
Please note that the TPMS is not a substitute for proper
tire maintenance, and it is the driver 's responsibility to
maintain correct tire pressure, even if under-inflation has
not reached the level to trigger illumination of the TPMS
low tire pressure telltale.
13. Temperature Gauge
The temperature gauge shows engine coolant tempera-
ture. Any reading within the normal range indicates that
the engine cooling system is operating satisfactorily.
The gauge pointer will likely indicate a higher tempera-
ture when driving in hot weather, up mountain grades,
or when towing a trailer. It should not be allowed to
exceed the upper limits of the normal operating range.
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4

Operating Tips
Window Fogging
Windows will fog on the inside when the humidity inside
the vehicle is high. This often occurs in mild or cool
temperatures when it's rainy or humid. In most cases
turning on the Air-conditioning (pressing the snowflake
button) will clear the fog. Adjust the temperature control,
air direction and blower speed to maintain comfort.
As the temperature gets colder it may be necessary to
direct air onto the windshield. Adjust the temperature
control and blower speed to maintain comfort. Higher
blower speeds will reduce fogging. Interior fogging on
the windshield can be quickly removed by selecting the
defrost mode.
Regular cleaning of the inside of the windows with a
non-filming cleaning solution (vinegar and water works
very well) will help prevent contaminates (cigarettesmoke, perfumes, etc.) from sticking to the windows.
Contaminates increase the rate of window fogging.Summer Operation
Air conditioned vehicles must be protected with a high
quality antifreeze coolant during summer to provide
proper corrosion protection and to raise the boiling point
of the coolant for protection against overheating. A 50 %
concentration is recommended. Refer to Recommended
Fluids and Genuine Parts for the proper coolant type.
When using the air conditioner in extremely heavy traffic
in hot weather especially when towing a trailer, addi-
tional engine cooling may be required. If this situation is
encountered, operate the transmission in a lower gear to
increase engine RPM, coolant flow and fan speed. When
stopped in heavy traffic, it may be necessary to shift into
N (Neutral) and depress the accelerator slightly for fast
idle operation to increase coolant flow and fan speed.
228 UNDERSTANDING YOUR INSTRUMENT PANEL

mTrailer Towing.........................277
NCommon Towing Definitions.............277
NTrailer Hitch Classification...............281
NTrailer Towing Weights
(Maximum Trailer Weight Ratings).........282NTrailer And Tongue Weight..............282
NTowing Requirements..................284
NTowing Tips.........................288
mRecreational Towing (Behind Motorhome, Etc.) . . 289
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can also provide the driver with more control during
passing, city driving, mountain driving, trailer towing,
and many other situations.
Autostick Operation
By placing the shift lever in the D (Drive) position the
lever can be moved from side to side. This allows the
driver to engage the AutoStick mode. Moving the shift
lever to the right (+) or the left (-) will engage the
Autostick mode. In normal driving mode (Boxed ªDº
displayed in the PRNDL), moving the shift lever to the
right (+) will engage the Autostick mode putting the
transmission in the currently engaged gear. Moving the
shift lever to the Left (-) will engage the Autostick mode
and downshift the transmission 1 gear. For example, the
transmission is in Normal Mode and is currently operat-
ing in 3rd gear, a boxed D is displayed in the PRNDL, a
push to the right will engage the Autostick mode in 3rd
and a Boxed 3 will be displayed in the PRNDL. A push to
the left (-) will engage Autostick mode and downshift to2nd gear and a Boxed 2 will be displayed in the PRNDL.
Once Autostick mode is engaged a move to the Right (+)
or left (-) will trigger a upshift (+) or trigger a downshift
(-).
NOTE:In the Autostick mode, the transmission will
only shift up and down when Left or Right (D-/D+) is
manually selected by the driver.
The transmission will not allow a downshift if the
downshift would result in a engine overspeed condition.
The transmission will always allow a upshift from 1st to
2nd gear, however 2nd - 3rd, 3rd - 4th, and 4th ± 5th
upshifts will not be allowed if the vehicle speed is to low
to maintain operation in the selected gear. The transmis-
sion will automatically downshift as the vehicle slows to
a stop.
When in the Autostick mode, as the engine RPM nears
the engine maximum speed, an ªUPSHIFTº message will
appear in the Electronic Vehicle Information Center
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Loading
The vehicle maximum load on the tire must not exceed
the load carrying capacity of the tire on your vehicle. You
will not exceed the tire's load carrying capacity if you
adhere to the loading conditions, tire size, and cold tire
inflation pressures specified on the ªTire and Loading
Informationº placard and in the ªVehicle Loadingº sec-
tion of this manual.
NOTE:Under a maximum loaded vehicle condition,
gross axle weight ratings (GAWR's) for the front and rear
axles must not be exceeded. For further information on
GAWR's, vehicle loading, and trailer towing, refer to the
ªVehicle Loadingº section of this manual.
To determine the maximum loading conditions of your
vehicle, locate the statement ªThe combined weight of
occupants and cargo should never exceed XXX kg or XXX
lbs.º on the Tire and Loading Information placard. Thecombined weight of occupants, cargo/luggage and
trailer tongue weight (if applicable) should never exceed
the weight referenced here.
Steps for Determining Correct Load Limit
1. Locate the statement ªThe combined weight of occu-
pants and cargo should never exceed XXX poundsº on
your vehicle's placard.
2. Determine the combined weight of the driver and
passengers that will be riding in your vehicle.
3. Subtract the combined weight of the driver and pas-
sengers from XXX kilograms or XXX pounds.
4. The resulting figure equals the available amount of
cargo and luggage load capacity. For example, if ªXXXº
amount equals 1400 lbs. and there will be five 150 lb.
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passengers in your vehicle, the amount of available cargo
and luggage load capacity is 650 lbs. (since 5 x 150 = 750,
and 1400 ± 750 = 650 lbs.)
5. Determine the combined weight of luggage and cargo
being loaded on the vehicle. That weight may not safely
exceed the available cargo and luggage load capacity
calculated in Step 4.
6. If your vehicle will be towing a trailer, load from your
trailer will be transferred to your vehicle. Consult this
manual to determine how this reduces the available
cargo and luggage load capacity of your vehicle.NOTE:The following table shows examples on how to
calculate total load, cargo/luggage, and towing capaci-
ties of your vehicle with varying seating configurations
and number and size of occupants. This table is for
illustration purposes only and may not be accurate for
the seating and load carry capacity of your vehicle.
NOTE:For the following example, the combined weight
of occupants and cargo should never exceed 865 lbs. (392
Kg).
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WARNING!
²Never add fuel when the engine is running.
²Never have any smoking materials lit in or near
the vehicle when the fuel cap is removed or the
tank filled.
TRAILER TOWING
In this section you will find safety tips and information
on limits to the type of towing you can reasonably do
with your vehicle. Before towing a trailer carefully re-
view this information to tow your load as efficiently and
safely as possible.
To maintain warranty coverage, follow the requirements
and recommendations in this manual concerning ve-
hicles used for trailer towing.
Common Towing Definitions
The following trailer towing related definitions will assist
you in understanding the following information:
Gross Vehicle Weight Rating (GVWR)
The GVWR is the total allowable weight of your vehicle.
This includes driver, passengers, cargo and tongue
weight. The total load must be limited so that you do not
exceed the GVWR.
Gross Trailer Weight (GTW)
The gross trailer weight (GTW) is the weight of the trailer
plus the weight of all cargo, consumables and equipment
(permanent or temporary) loaded in or on the trailer in its
9loaded and ready for operation9condition. The recom-
mended way to measure GTW is to put your fully loaded
trailer on a vehicle scale. The entire weight of the trailer
must be supported by the scale.
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Gross Combination Weight Rating (GCWR)
The gross combination weight rating (GCWR) is the total
permissible weight of your vehicle and trailer when
weighed in combination. (Note that GCWR ratings in-
clude a 150 lbs (68 kg) allowance for the presence of a
driver).
Gross Axle Weight Rating (GAWR)
The GAWR is the maximum capacity of the front and rear
axles. Distribute the load over the front and rear axles
evenly. Make sure that you do not exceed either front or
rear GAWR.
WARNING!
It is important that you do not exceed the maximum
front or rear GAWR. A dangerous driving condition
can result if either rating is exceeded. You could lose
control of the vehicle and have an accident.
Tongue Weight (TW)
The downward force exerted on the hitch ball by the
trailer. In most cases it should not be less than 10% or
more than 15% of the trailer load. You must consider this
as part of the load on your vehicle.
Frontal Area
The maximum height and maximum width of the front of
a trailer.
Trailer Sway Control
The trailer sway control is a telescoping link that can be
installed between the hitch receiver and the trailer tongue
that typically provides adjustable friction associated with
the telescoping motion to dampen any unwanted trailer
swaying motions while traveling.
Weight-Carrying Hitch
A weight-carrying hitch supports the trailer tongue
weight, just as if it were luggage located at a hitch ball or
some other connecting point of the vehicle. These kind of
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hitches are the most popular on the market today and
they're commonly used to tow small- and medium-sized
trailers.
Weight-Distributing Hitch
A weight-distributing system works by applying lever-
age through spring (load) bars. They are typically used
for heavier loads, to distribute trailer tongue weight to
the tow vehicle's front axle and the trailer axle(s). When
used in accordance with the manufacturers' directions, it
provides for a more level ride, offering more consistent
steering and brake control thereby enhancing towing
safety. The addition of a friction/hydraulic sway control
also dampens sway caused by traffic and crosswinds and
contributes positively to tow vehicle and trailer stability.
Trailer sway control and a weight distributing (load
equalizing) hitch are recommended for heavier Tongue
Weights (TW) and may be required depending on Vehicle
and Trailer configuration/loading to comply with gross
axle weight rating (GAWR) requirements.
WARNING!
An improperly adjusted Weight Distributing Hitch
system may reduce handling, stability, braking per-
formance, and could result in an accident.
Weight Distributing Systems may not be compatible
with Surge Brake Couplers. Consult with your hitch
and trailer manufacturer or a reputable Recreational
Vehicle dealer for additional information.
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Trailer Hitch Classification
Your vehicle may be factory equipped for safe towing of
trailers weighing over 3,500 lbs (1 587 kg) with the
optional Trailer Tow Prep Package. See your dealer for
package content.
The following chart provides the industry standard for
the maximum trailer weight a given trailer hitch class can
tow and should be used to assist you in selecting the
correct trailer hitch for your intended towing condition.
Refer to the Trailer Towing Weights (Maximum Trailer
Weight Ratings) chart for the Max. GTW towable for your
given drivetrain.Trailer Hitch Classification
Class Max. GTW (Gross Trailer
Wt.)
Class I - Light Duty 2,000 lbs (907 kg)
Class II - Medium
Duty3,500 lbs (1 587 kg)
Class III - Heavy Duty 5,000 lbs (2 268 kg)
Class IV - Extra
Heavy Duty10,000 lbs (4 540 kg)
All trailer hitches should be professionally installed on
your vehicle.
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