2007 JEEP GRAND CHEROKEE air condition

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.
Your air conditioning system is also equipped with an
automatic recirculation system. When the system senses
a heavy load or high heat conditions, it may use partial
Recirculation A/C mode to provide additional comfort.Winter Operation
When operating the system during the winter months,
make sure the air intake, located directly in front of the
windshield, is free of ice, slush, snow, or other obstruc-
tions.
Vacation Storage
Anytime you store your vehicle, or keep it out of service
(i.e. vacation) for two weeks or more, run the air condi-
tioning system at idle for about five minutes in the fresh
air and high blower setting. This will insure adequate
system lubrication to minimize the possibility of com-
pressor damage when the system is started again.
UNDERSTANDING YOUR INSTRUMENT PANEL 243
4

If the engine shows no sign of starting after two 15
second periods of cranking with the accelerator pedal
held to the floor, the normal starting procedure should be
repeated.
WARNING!
Never pour fuel or other flammable liquids into the
throttle body air inlet opening in an attempt to start
the vehicle. This could result in a flash fire causing
serious personal injury.
Normal Starting — Diesel Engines
1. Turn the ignition key to the ON position.
2. Watch for the “Glow Plug Indicator Light” in the
instrument cluster. Refer to “Instrument Cluster” in
Section 4. It will glow for two to ten seconds or more,depending on engine temperature. When the “Glow Plug
Indicator Light” goes out, the engine is ready to start.
3.Do notpress the accelerator. Turn the ignition key
briefly to START position, and release it. The starter
motor will continue to run, but will automatically disen-
gage itself when the engine is running.
NOTE:The starter motor may run up to 30 seconds in
very cold conditions until the engine is started. The
starter can be disengaged by turning the ignition key to
the OFF position, if required.
4. After the engine starts, allow it to idle for approxi-
mately 30 seconds before driving. This allows oil to
circulate and lubricate the turbocharger.
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operation is similar. Follow the Quadra-Trac IItransfer
case shifting information, preceding this section, for
shifting this system.
ON-ROAD DRIVING TIPS
Utility vehicles have higher ground clearance and a
narrower track to make them capable of performing in a
wide variety of off-road applications. Specific design
characteristics give them a higher center of gravity than
ordinary cars.
An advantage of the higher ground clearance is a better
view of the road, allowing you to anticipate problems.
They are not designed for cornering at the same speeds as
conventional 2-wheel drive vehicles any more than low-
slung sports cars are designed to perform satisfactorily in
off-road conditions. If at all possible, avoid sharp turns or
abrupt maneuvers. As with other vehicles of this type,
failure to operate this vehicle correctly may result in loss
of control or vehicle rollover.
OFF-ROAD DRIVING TIPS
NOTE:Prior to off-road driving, remove the front air
dam to prevent damage. The front air dam is attached to
the lower front fascia with quarter turn fasteners, and can
be removed by hand.
When To Use 4WD LOW Range — If Equipped
When off-road driving, shift to 4WD LOW for additional
traction. This range should be limited to extreme situa-
tions such as deep snow, mud, or sand where additional
low speed pulling power is needed. Vehicle speeds in
excess of 25 mph (40 km/h) should be avoided when in
4WD LOW range.
Driving Through Water
Although your vehicle is capable of driving through
water, there are a number of precautions that must be
considered before entering the water:
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check tire pressure. Do not make a visual judgement
when determining proper inflation. Radial tires may look
properly inflated even when they are under inflated.
CAUTION!
After inspecting or adjusting the tire pressure al-
ways reinstall the valve stem cap–if equipped. This
will prevent moisture and dirt from entering the
valve stem, which could damage the valve stem.
Inflation pressures specified on the placard are always
“cold tire inflation pressure”. Cold tire inflation pressure
is defined as the tire pressure after the vehicle has not
been driven for at least 3 hours, or driven less than 1 mile
(1 km) after a 3 hour period. The cold tire inflation
pressure must not exceed the maximum inflation pres-
sure molded into the tire side wall.Check tire pressures more often if subject to a wide range
of outdoor temperatures, as tire pressures vary with
temperature changes.
Tire pressures change by approximately 1 psi (7 kPa) per
12° F (7° C) of air temperature change. Keep this in mind
when checking tire pressure inside a garage especially in
the winter.
Example: If garage temperature = 68° F (20° C) and the
outside temperature = 32° F (0° C) then the cold tire
inflation pressure should be increased by 3 psi (21 kPa),
which equals 1 psi (7 kPa) for every 12° F (7° C) for this
outside temperature condition.
Tire pressure may increase from 2 to 6 psi (13 to 40 kPa)
during operation. DO NOT reduce this normal pressure
build up or your tire pressure will be too low.
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5

Tire Pressures for High Speed Operation
The manufacturer advocates driving at safe speeds
within posted speed limits. Where speed limits or condi-
tions are such that the vehicle can be driven at high
speeds, maintaining correct tire inflation pressure is very
important. Increased tire pressure and reduced vehicle
loading may be required for high speed vehicle opera-
tion. Refer to original equipment or an authorized tire
dealer for recommended safe operating speeds, loading
and cold tire inflation pressures.
WARNING!
High speed driving with your vehicle under maximum
load is dangerous. The added strain on your tires could
cause them to fail. You could have a serious accident.
Don’t drive a vehicle loaded to the maximum capacity
at continuous speeds above 75 mph (120 km/h).
Radial-Ply Tires
WARNING!
Combining radial ply tires with other types of tires
on your vehicle will cause your vehicle to handle
poorly. The instability could cause an accident. Al-
ways use radial tires in sets of four. Never combine
them with other types of tires.
Cuts and punctures in radial tires are repairable only in
the tread area because of sidewall flexing. Consult your
dealer for radial tire repairs.
Tire Spinning
When stuck in mud, sand, snow, or ice conditions, do not
spin your vehicle’s wheels above 35 mph (55 km/h).
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will automatically update and the “Tire Pressure Moni-
toring Light” will extinguish once the updated tire pres-
sures have been received. The vehicle may need to be
driven for up to 10 minutes above 15 mph (24 km/h) to
receive this information. A low spare tire will not cause
the “Tire Pressure Monitoring Telltale Light” to illumi-
nate or the chime to sound.
The “Tire Pressure Monitoring Telltale Light” will flash
on and off for 60 seconds, and an audible chime will
sound when a system fault is detected. The flash cycle
will repeat every ten minutes, without an audible chime,
until the fault condition no longer exists. If the ignition
key is cycled, this sequence will repeat, providing the
system fault still exists.
NOTE:If your vehicle is equipped with a matching full
size spare tire, it has a tire pressure monitoring sensor,
and can be monitored by the Tire Pressure Monitoring
System (TPMS). In the event that the matching full sizespare tire is swapped with a low pressure road tire, the
next ignition key cycle will still show the “Tire Pressure
Monitoring Telltale Light” to be ON, and a chime to
sound. Driving the vehicle for up to 10 minutes above 15
mph (24 km/h) will turn OFF the “Tire Pressure Moni-
toring Telltale Light” as long as the spare tire or any other
road tire(s) are not below the low pressure warning
threshold.
NOTE:If your vehicle is equipped with a non-matching
full size spare tire, it does not have a tire pressure
monitoring sensor. Therefore, it will not be monitored by
the Tire Pressure Monitor System (TPMS). In the event
that the non-matching full size spare tire is swapped with
a low pressure road tire, each ignition key cycle will still
show the “Tire Pressure Monitoring Telltale Light” to be
ON, and a chime to sound. After the original road tire has
been properly repaired, and put back onto the vehicle in
place of the non-matching full size spare tire, the TPMS
298 STARTING AND OPERATING

5.7L Engines (If Equipped)
The 5.7L engine is designed to meet all
emissions regulations and provide satisfac-
tory fuel economy and performance when
using high quality unleaded gasoline hav-
ing an octane range of 87 to 89. The manu-
facturer recommends the use of 89 octane
for optimum performance. The use of premium gasoline
is not recommended. Under normal conditions, the use of
premium gasoline will not provide a benefit over high
quality regular and mid-grade gasolines, and in some
circumstances may result in poorer performance.
Light spark knock at low engine speeds is not harmful to
your engine. However, continued heavy spark knock at
high speeds can cause damage and immediate service is
required.Poor quality gasoline can cause problems such as hard
starting, stalling and hesitations. If you experience these
symptoms, try another brand of gasoline before consid-
ering service for the vehicle.
Over 40 auto manufacturer’s world wide have issued and
endorsed consistent gasoline specifications (the World-
wide Fuel Charter, WWFC) to define fuel properties
necessary to deliver enhanced emissions, performance,
and durability for your vehicle. The manufacturer recom-
mends the use of gasoline that meets the WWFC speci-
fications if they are available.
Reformulated Gasoline
Many areas of the country require the use of cleaner
burning gasoline referred to as “Reformulated Gasoline”.
Reformulated gasolines contain oxygenates, and are spe-
cifically blended to reduce vehicle emissions and im-
prove air quality.
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It is even more important to look for gasolines without
MMT in Canada, because MMT can be used at levels
higher than those allowed in the United States.
MMT is prohibited in Federal and California reformu-
lated gasoline.
Materials Added To Fuel
All gasoline sold in the United States is required to
contain effective detergent additives. Use of additional
detergents or other additives is not needed under normal
conditions and would result in additional cost. Therefore
you should not have to add anything to the fuel.
Fuel System Cautions
CAUTION!
Follow these guidelines to maintain your vehicle’s
performance:
•The use of leaded gas is prohibited by Federal law.
Using leaded gasoline can impair engine performance,
damage the emission control system.
•An out-of-tune engine, or certain fuel or ignition
malfunctions, can cause the catalytic converter to
overheat. If you notice a pungent burning odor or
some light smoke, your engine may be out of tune or
malfunctioning and may require immediate service.
Contact your dealer for service assistance.
•The use of fuel additives which are now being sold as
octane enhancers is not recommended. Most of these
products contain high concentrations of methanol.
Fuel system damage or vehicle performance problems
resulting from the use of such fuels or additives is not
the responsibility of the manufacturer.
NOTE:Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
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