2012 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.
4
UNDERSTANDING YOUR INSTRUMENT PANEL 293

vehicle is experiencing a problem with the charging
system. Obtain SERVICE IMMEDIATELY. See an autho-
rized dealer.
If jump starting is required, refer to “Jump Starting
Procedures” in “What To Do In Emergencies”.
•Electronic Throttle Control (ETC) Light
This light informs you of a problem with the
Electronic Throttle Control (ETC) system. The
light will come on when the ignition is first
turned ON and remain on briefly as a bulb
check. If the light does not come on during starting, have
the system checked by an authorized dealer.
If a problem is detected, the light will come on while the
engine is running. Cycle the ignition key when the
vehicle has completely stopped and the shift lever is
placed in the PARK position. The light should turn off.If the light remains lit with the engine running, your
vehicle will usually be drivable. However, see an autho-
rized dealer for service as soon as possible. If the light is
flashing when the engine is running, immediate service is
required. You may experience reduced performance, an
elevated/rough idle or engine stall and your vehicle may
require towing.
•Engine Temperature Warning Light
This light warns of an overheated engine condi-
tion. As temperatures rise and the gauge ap-
proachesH,this indicator will illuminate and a
single chime will sound after reaching a set threshold.
Further overheating will cause the temperature gauge to
passH,the indicator will continuously flash and a
continuous chime will occur until the engine is allowed
to cool.
306 UNDERSTANDING YOUR INSTRUMENT PANEL

If the light turns on while driving, safely pull over and
stop the vehicle. If the A/C system is on, turn it off. Also,
shift the transmission into NEUTRAL and idle the ve-
hicle. If the temperature reading does not return to
normal, turn the engine off immediately and call for
service. Refer to “If Your Engine Overheats” in “What To
Do In Emergencies” for more information.
•Transmission Temperature Warning Light
This light indicates that there is excessive trans-
mission fluid temperature that might occur
with severe usage such as trailer towing. It may
also occur when operating the vehicle in a high
torque converter slip condition, such as 4-wheel-drive
operation (e.g., snow plowing, off- road operation). If this
light comes on, stop the vehicle and run the engine at idle
or faster, with the transmission in NEUTRAL until the
light goes off.
CAUTION!
Continuous driving with the Transmission Tempera-
ture Warning Light illuminated will eventually cause
severe transmission damage or transmission failure.
WARNING!
If the Transmission Temperature Warning Light is
illuminated and you continue operating the vehicle,
in some circumstances you could cause the fluid to
boil over, come in contact with hot engine or exhaust
components and cause a fire.
4
UNDERSTANDING YOUR INSTRUMENT PANEL 307

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
NOTE:In some cases during high temperature trailer
tow operation the Air Conditioning system performance
may be reduced. This is to help protect the engine from
overheating during the high load condition.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
obstructions.
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 ensure adequate
system lubrication to minimize the possibility of com-
pressor damage when the system is started again.
368 UNDERSTANDING YOUR INSTRUMENT PANEL

can be used at levels higher than those allowed in the
United States. MMT is prohibited in Federal and Califor-
nia reformulated 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 they 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 emissions 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 authorized dealer for service
assistance.
(Continued)
438 STARTING AND OPERATING

WHAT TO DO IN EMERGENCIES
CONTENTS
Hazard Warning Flashers................ 460
If Your Engine Overheats................ 460
Jacking And Tire Changing............... 461
▫RunFlatTires ....................... 461
Jump-Starting........................ 462▫Preparations For Jump-Start............. 462
▫Jump-Starting Procedure............... 464
Emergency Tow Hooks — If Equipped...... 466
Shift Lever Override................... 467
Towing A Disabled Vehicle............... 468
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 flashers.
This is an emergency warning system and it should not
be used when the vehicle is in motion. Use it when your
vehicle is disabled and it is creating a safety hazard for
other motorists.
When you must leave the vehicle to seek assistance, the
Hazard Warning flashers will continue to operate even
though the ignition is placed in the OFF position.
NOTE:With extended use the Hazard Warning flashers
may wear 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, place the transmission
in NEUTRAL, but do not increase the engine idle
speed.
NOTE:There are steps that you can take to slow down
an impending overheat condition:
•If your air conditioner (A/C) is on, turn it off. The A/C
system adds heat to the engine cooling system and
turning the A/C off can help remove this heat.
•You can also turn the temperature control to maximum
heat, the mode control to floor and the blower control
460 WHAT TO DO IN EMERGENCIES

CAUTION!
The catalytic converter requires the use of unleaded
fuel only. Leaded gasoline will destroy the effective-
ness of the catalyst as an emissions control device
and may seriously reduce engine performance and
cause serious damage to the engine.
Under normal operating conditions, the catalytic con-
verter will not require maintenance. However, it is im-
portant to keep the engine properly tuned to assure
proper catalyst operation and prevent possible catalyst
damage.
CAUTION!
Damage to the catalytic converter can result if your
vehicle is not kept in proper operating condition. In
the event of engine malfunction, particularly involv-
ing engine misfire or other apparent loss of perfor-
mance, have your vehicle serviced promptly. Contin-
ued operation of your vehicle with a severe
malfunction could cause the converter to overheat,
resulting in possible damage to the converter and the
vehicle.
NOTE:Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
7
MAINTAINING YOUR VEHICLE 487