2005 JEEP GRAND CHEROKEE engine overheat

12. Tire Pressure Monitor Warning Light
This light will turn on continuously when there
is a low tire pressure condition. The light will
also turn on if a problem exists with any tire
sensor. When a system fault is detected, the
indicator lamp will flash repetitively for ten seconds. The
flash cycle will repeat every ten minutes or until the fault
condition is removed and reset. The light will remain on
or flashing until the tire pressure is properly set or the
problem with the sensor is corrected.
This light will turn on momentarily as a bulb check when
the engine is started.
When the tire pressure monitoring system warning light
is lit, one or more of your tires is significantly underin-
flated. You should stop and check your tires as soon as
possible, and inflate them to the proper pressure as
indicated on the tire and loading information placard.
Driving on a significantly underinflated tire causes thetire to overheat and can lead to tire failure. Underinfla-
tion also reduces fuel efficiency and tire tread life, and
may affect the vehicle’s handling and stopping ability.
Each tire, including the spare, should be checked
monthly when cold and set to the recommended inflation
pressure as specified in the tire and loading information
placard. (See page 269 for more information.)
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.
UNDERSTANDING YOUR INSTRUMENT PANEL 167
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NOTE:Extended use of recirculation may cause the
windows to fog. If the interior of the windows begins to
fog, press the “Recirculate” icon button to return to
outside air. Some temp./humidity conditions will cause
captured interior air to condense on windows and ham-
per visibility. For this reason, the system will not allow
“Recirculate” to be selected while in the defrost or
defrost/floor modes. Attempting to use the recirculation
while in these modes will cause the LED in the button to
blink and then turn off.
Summer Operation
The engine cooling system in air conditioned vehicles
must be protected with a high-quality antifreeze coolant
to provide proper corrosion protection and to protect
against engine overheating. A 50% solution of ethylene
glycol antifreeze coolant in water is recommended. Refer
to “Maintenance Procedures” in Section 7 of this manual
for proper coolant selection.
Winter Operation
Use of the air Recirculation mode during winter months
is not recommended because it may cause window
fogging.
NOTE:Refer to the “Operating Tips” chart (for Manual
A/C Control) in this section for suggested control set-
tings in different weather conditions.
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.
224 UNDERSTANDING YOUR INSTRUMENT PANEL

a downshift may occur. This is a normal part of the
overheat protection strategy when operating in the
“Tow/Haul” mode.
The transmission will downshift from Overdrive to the
most desirable gear if the accelerator pedal is fully
depressed at vehicle speeds above approximately 35 mph
(56 km/h).
When To Use “TOW/HAUL” Mode — If Equipped
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent transmission shifting oc-
curs, press the “TOW/HAUL” button. This will improve
performance and reduce the potential for transmission
overheating or failure due to excessive shifting. When
operating in “TOW/HAUL” mode, the transmission will
shift to 3rd gear and 4th will be enabled under steady
cruise conditions.The “TOW/HAUL” light will illuminate in the instru-
ment cluster to indicate when the switch has been
activated. Pressing the switch a second time restores
normal operation. If the “TOW/HAUL” mode is desired,
the switch must be pressed each time the engine is
started.
Tow/Haul Button
STARTING AND OPERATING 237
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NOTE:The Electronic Stability Program (ESP) and
Traction Control (if equipped) should be turned OFF
before attempting to rock the vehicle. Refer to Section 3 of
this manual.
The least amount of accelerator pedal pressure to main-
tain the rocking motion without spinning the wheels or
racing the engine is most effective. Racing the engine or
spinning the wheels, due to the frustration of not freeing
the vehicle, may lead to transmission overheating and
failure. Allow the engine to idle with the transmission
selector in N (Neutral) for at least one minute after every
five rocking-motion cycles. This will minimize overheat-
ing and reduce the risk of transmission failure during
prolonged efforts to free a stuck vehicle.CAUTION!
When “rocking” a stuck vehicle by moving between
“First” and R (Reverse), do not spin the wheels faster
than 15 mph (24 km/h), or drivetrain damage may
result.
FOUR-WHEEL DRIVE OPERATION
Quadra-Trac IOperating
Instructions/Precautions — If Equipped
The Quadra-Trac Iis a single speed (HI range only)
transfer case which provides convenient full-time
4–wheel drive. No driver interaction is required. This
transfer case divides engine torque almost evenly with 48
percent of engine torque to the front axle and 52 percent
of engine torque to the rear axle. The Brake Traction
Control System (BTC), which combines standard ABS
STARTING AND OPERATING 239
5

CAUTION!
The Anti-Lock Brake System is subject to possible
detrimental effects of electronic interference caused
by improperly installed after-market radios or tele-
phones.
NOTE:During severe braking conditions, a pulsing
sensation may occur and a clicking noise will be heard.
This is normal, indicating that the Anti-Lock Brake
System is functioning.
WARNING!
To use your brakes and accelerator more safely,
follow these tips:
•Do not “ride” the brakes by resting your foot on the
pedal. This could overheat the brakes and result in
unpredictable braking action, longer stopping dis-
tances, or brake damage.
•When descending mountains or hills, repeated brak-
ing can cause brake fade with loss of braking control.
Avoid repeated heavy braking by downshifting the
transmission or locking out overdrive whenever pos-
sible.
•Engines may idle at higher speeds during warm-up,
which could cause rear wheels to spin and result in
loss of vehicle control. Be especially careful while
driving on slippery roads, in close-quarter maneuver-
ing, parking or stopping.
•Do not drive too fast for road conditions, especially
when roads are wet or slushy. A wedge of water can
248 STARTING AND OPERATING

•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.
Carbon Monoxide Warnings
WARNING!
Carbon monoxide (CO) in exhaust gases is deadly.
Follow the precautions below to prevent carbon
monoxide poisoning:
•Do not inhale exhaust gases. They contain carbon
monoxide, a colorless and odorless gas which can kill.
Never run the engine in a closed area, such as a
garage, and never sit in a parked vehicle with the
engine running for an extended period. If the vehicle is
stopped in an open area with the engine running for
more than a short period, adjust the ventilation system
to force fresh, outside air into the vehicle.
280 STARTING AND OPERATING

Cooling System Tips—Trailer Towing
To reduce potential for engine and transmission over-
heating in high ambient conditions, take the following
actions:
•City Traffic
When stopped, put transmission in N (Neutral) and
increase engine idle speed.
•Highway Driving
Reduce speed.
•Air Conditioning
Turn off temporarily.
To reduce the potential for transmission overheating,
turn the “TOW/HAUL” feature on when driving in hilly
areas or downshift the transmission to the next lower
gear range to eliminate excessive transmission shifting.
This action will also reduce the possibility of transmis-
sion overheating and provide better engine braking.
7–Pin Connector
STARTING AND OPERATING 287
5

WHAT TO DO IN EMERGENCIES
CONTENTS

Hazard Warning Flashers.................296

If Your Engine Overheats.................297

Jacking And Tire Changing................298
▫Jack Location........................298
▫Spare Tire Stowage....................299
▫Spare Tire Removal....................299
▫Preparations For Jacking................300▫Jacking Instructions....................300

Jump Starting Procedure..................303

Emergency Tow Hooks — If Equipped........305

Towing A Disabled Vehicle................306
▫2WD Models Only....................306
▫4WD Models Only....................306
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