2010 JEEP GRAND CHEROKEE engine overheat

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.
CAUTION!
Driving with a hot engine cooling system could
damage your vehicle. If the temperature gauge reads
“H” pull over and stop the vehicle. Idle the vehicle
with the air conditioner turned off until the pointer
drops back into the normal range. If the pointer
remains on the “H” and you hear continuous chimes,
turn the engine off immediately, and call an autho-
rized dealership for service.
WARNING!
A hot engine cooling system is dangerous. You or
others could be badly burned by steam or boiling
coolant. You may want to call an authorized dealer-
ship for service if your vehicle overheats. If you
decide to look under the hood yourself, see “Main-
taining Your Vehicle”. Follow the warnings under the
Cooling System Pressure Cap paragraph.
14. Electronic Vehicle Information Center (EVIC)
Display
When the appropriate conditions exist, this display
shows the Electronic Vehicle Information Center (EVIC)
messages. Refer to “Electronic Vehicle Information Cen-
ter”.
164 UNDERSTANDING YOUR INSTRUMENT PANEL

defrost/floor modes. Attempting to use Recirculation
while in these modes will cause the LED in the button to
blink and then turn off.
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 the air conditioning (pressing the snowflake
button) on 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 (cigarette
smoke, 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 the 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 Fluids, Lubri-
cants, and Genuine Parts in “Maintaining Your Vehicle”
for the proper coolant type.
When using the air conditioner in extremely heavy
traffic, in hot weather, especially when towing a trailer,
additional engine cooling may be required. If this situa-
tion is encountered, operate the transmission in a lower
gear to increase engine RPM, coolant flow and fan speed.4
UNDERSTANDING YOUR INSTRUMENT PANEL 231

•transmission has reached normal operating
temperature.
NOTE: If the vehicle is started in extremely cold tem-
peratures, the transmission may not shift into Overdrive
and will automatically select the most desirable gear for
operation at this temperature. Normal operation will
resume when the transmission fluid temperature has
risen to a suitable level. Refer to the “Note” under
“Torque Converter Clutch” in this section.
During cold temperature operation you may notice de-
layed upshifts, depending on engine and transmission
temperature. This feature improves the warmup time of
the engine and transmission.
If the transmission temperature gets extremely hot, the
transmission will automatically select the most desirable
gear for operation at this temperature. If the transmission
temperature becomes hot enough, the “TRANSMISSION OVER TEMP” message may display, and the transmis-
sion may downshift out of Overdrive until the transmis-
sion cools down. After cool down, the transmission will
resume normal operation.
In high ambient temperatures with sustained high engine
speed and load, an upshift, followed shortly thereafter by
a downshift, may occur. The “TOW/HAUL Indicator
Light” will turn off. 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
pressed 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 switch. This will improve
5
STARTING AND OPERATING 249

performance and reduce the potential for transmission
overheating or failure due to excessive shifting. When
operating in TOW/HAUL mode, the transmission will
shift into direct gear and Overdrive will be enabled
under steady cruise conditions.The “TOW/HAUL Indicator Light” will illuminate in the
instrument 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.
Transmission Limp Home Mode
Transmission function is monitored for abnormal condi-
tions. If a condition is detected that could result in
transmission damage, the Transmission Limp Home
Mode will be engaged. In this mode, the transmission
will remain in the current gear (3.7L engine) or in direct
gear (5.7L engine) until the vehicle is brought to a stop.
To reset the transmission, use the following procedure:
1. Stop the vehicle.
2. Move the shift lever into the PARK position.
TOW/HAUL Switch
250 STARTING AND OPERATING

the transmission may not shift into the top Overdrive
gear (normal fifth gear) until the transmission fluid
and engine coolant are warm.
•If the vehicle has not been driven in several days, the
first few seconds of operation after shifting the trans-
mission into gear may seem sluggish. This is due to the
fluid partially draining from the torque converter into
the transmission. This condition is normal and will not
cause damage to the transmission. The torque con-
verter will refill within five seconds of shifting from
PARK into any other gear position.
Rocking the Vehicle
If the vehicle becomes stuck in snow, sand, or mud, it can
often be moved by a rocking motion. Move the shift lever
between DRIVE and REVERSE, while applying slight
pressure to the accelerator.NOTE:
The Electronic Stability Program (ESP) and
Traction Control System (TCS) (if equipped) should be
turned OFF before attempting to rock the vehicle. Refer
to “Electronic Brake Control System” in “Starting and
Operating” for further information.
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 shift lever in
NEUTRAL for at least one minute after every five
rocking-motion cycles. This will minimize overheating
and reduce the risk of transmission failure during pro-
longed efforts to free a stuck vehicle.
252 STARTING AND OPERATING

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 perfor-
mance and damage the emission control system.(Continued)
CAUTION! (Continued)
•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 authorized 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 concentra-
tions 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.
318 STARTING AND OPERATING

WHAT TO DO IN EMERGENCIES
CONTENTS
Hazard Warning Flashers ................ 346
 If Your Engine Overheats ................ 346
 Jacking And Tire Changing ............... 348
▫ Jack Location ....................... 348
▫ Spare Tire Stowage ................... 349
▫ Spare Tire Removal ................... 349
▫ Preparations For Jacking ............... 350
▫ Jacking Instructions ................... 351 
Jump-Starting Procedures ................ 355
▫ Preparations For Jump-Start ............. 356
▫ Jump-Starting Procedure ............... 357
 Emergency Tow Hooks — If Equipped ...... 359
 Towing A Disabled Vehicle ............... 359
▫ Two-Wheel Drive Models Only .......... 359
▫ Four-Wheel Drive Models Only .......... 360
6

HAZARD WARNING FLASHERS
The Hazard Warning flasher switch is located on the
switch bank just above the climate controls.Press the switch to turn on the Hazard Warning
flasher. When the switch is activated, all directional
turn signals will flash on and off to warn oncoming
traffic of an emergency. Press the switch a second time to
turn off the Hazard Warning flasher.
This is an emergency warning system and should not be
used when the vehicle is in motion. Use it when your
vehicle is disabled and is creating a safety hazard for
other motorists.
If it is necessary to leave the vehicle to go for service, the
Hazard Warning flasher will continue to operate with the
ignition key removed and the vehicle locked.
NOTE: With extended use, the Hazard Warning flasher
may run down your battery.
IF YOUR ENGINE OVERHEATS
In any of the following situations, you can reduce the
potential for overheating by taking the appropriate ac-
tion.
•On the highways — Slow down.
•In city traffic — While stopped, shift the transmission
to NEUTRAL, but do not increase the engine idle
speed.
346 WHAT TO DO IN EMERGENCIES