2012 JEEP GRAND CHEROKEE heating

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

NOTE:Even if the transmission can be reset, we recom-
mend that you visit your authorized dealer at your
earliest possible convenience. Your authorized dealer has
diagnostic equipment to determine if the problem could
recur.
If the transmission cannot be reset, authorized dealer
service is required.
Overdrive Operation
The automatic transmission includes an electronically
controlled Overdrive (fifth gear). The transmission will
automatically shift into the Overdrive gear if the follow-
ing conditions are present:
•the shift lever is in the DRIVE position,
•vehicle speed is sufficiently high, and
•the driver is not heavily pressing the accelerator.
When to Use TOW Mode
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent transmission shifting oc-
curs, select TOW mode, using the rotary switch on the
center console. Selecting TOW mode will improve per-
formance and reduce the potential for transmission over-
heating or failure due to excessive shifting. Refer to
“Selec-Terrain” in “Starting And Operating” for further
information.
AUTOSTICK
AutoStickis a driver-interactive transmission feature
that offers manual gear shifting to provide you with more
control of the vehicle. AutoStickallows you to maximize
engine braking, eliminate undesirable upshifts and
downshifts, and improve overall vehicle performance.
5
STARTING AND OPERATING 389

WARNING!
Overloading of your tires is dangerous. Overloading
can cause tire failure, affect vehicle handling, and
increase your stopping distance. Use tires of the
recommended load capacity for your vehicle. Never
overload them.
TIRES — GENERAL INFORMATION
Tire Pressure
Proper tire inflation pressure is essential to the safe and
satisfactory operation of your vehicle. Three primary
areas are affected by improper tire pressure:
Safety
WARNING!
•Improperly inflated tires are dangerous and can
cause collisions.
•Under-inflation increases tire flexing and can re-
sult in over-heating and tire failure.
•Over-inflation reduces a tire’s ability to cushion
shock. Objects on the road and chuckholes can
cause damage that result in tire failure.
•Over-inflated or under-inflated tires can affect
vehicle handling and can fail suddenly, resulting
in loss of vehicle control.
•Unequal tire pressures can cause steering prob-
lems. You could lose control of your vehicle.
(Continued)
418 STARTING AND OPERATING

Automatic Transmission
The DRIVE range can be selected when towing. How-
ever, if frequent shifting occurs while in this range, use
the AutoStickfeature to select a lower gear.
NOTE:Using a lower gear while operating the vehicle
under heavy operating conditions will improve perfor-
mance and extend transmission life by reducing exces-
sive shifting and heat build up. This action will also
provide better engine braking.
The automatic transmission fluid and filter should be
changed if you REGULARLY tow a trailer for more than
45 minutes of continuous operation. Refer to the “Main-
tenance Schedule” for the proper maintenance intervals.
Electronic Speed Control – If Equipped

Do not use in hilly terrain or with heavy loads.
When using the speed control, if you experience speed
drops greater than 10 mph (16 km/h), disengage until
you can get back to cruising speed.
Use speed control in flat terrain and with light loads to
maximize fuel efficiency.
Cooling System
To reduce potential for engine and transmission over-
heating, take the following actions:
City Driving
When stopped for short periods of time, shift the trans-
mission into NEUTRAL and increase engine idle speed.
Highway Driving
Reduce speed.
Air Conditioning
Turn off temporarily.
456 STARTING AND OPERATING

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

WARNING!
A hot exhaust system can start a fire if you park over
materials that can burn. Such materials might be
grass or leaves coming into contact with your exhaust
system. Do not park or operate your vehicle in areas
where your exhaust system can contact anything that
can burn.
In unusual situations involving grossly malfunctioning
engine operation, a scorching odor may indicate severe
and abnormal catalyst overheating. If this occurs, the
vehicle should be stopped, the engine shut off and the
vehicle allowed to cool. Thereafter, service, including a
tune-up to manufacturer’s specifications, should be ob-
tained immediately.To minimize the possibility of catalyst damage:•Do not shut off the engine or interrupt the ignition
when the transmission is in gear and the vehicle is in
motion.
•Do not try to start engine by pushing or towing the
vehicle.
•Do not idle the engine with any spark plug wires
disconnected or removed, such as when diagnostic
testing, or for prolonged periods during very rough
idling or malfunctioning operating conditions.
488 MAINTAINING YOUR VEHICLE

Cavity Cartridge
FuseMini
FuseDescription
M2 20 Amp
YellowElectronic Limit
Slip Differential/
Air Suspension
M3 20 Amp
YellowLiftgate/Headrest
M5 25 Amp
Natural115V AC Power
Inverter
M6 20 Amp
YellowCigar Lighter
M7 20 Amp
YellowPower Outlet #2
(Switchable)
M8 20 Amp
YellowFront Heated Seat
& Steering Wheel
M9 20 Amp
YellowRear Heated SeatsCavity Cartridge
FuseMini
FuseDescription
M10 15 Amp
BlueVideo/Universal
Garage Door
Opener
M11 10 Amp
RedHeating, Ventilation
& Air Conditioning
(Climate Control
System)
M12 30 Amp
GreenRadio/Amplifier
M13 20 Amp
YellowInstrument Cluster
M14 20 Amp
YellowBack Up Camera –
If Equipped
7
MAINTAINING YOUR VEHICLE 507

Jump Starting....................... 462
Tow Hooks......................... 466
Emission Control System Maintenance......... 473
Engine............................... 471
Air Cleaner Filter.................... 479
Break-In Recommendations.............. 94
Checking Oil Level................... 476
Compartment....................... 471
Coolant (Antifreeze).................. 489
Cooling ........................... 489
Exhaust Gas Caution.............. 47,96,439
Fails to Start........................ 379
Flooded, Starting..................... 379
Fuel Requirements.................435,517
Jump Starting....................... 462
Oil ............................476,517
Oil Change Interval................... 477
Oil Selection.....................477,517
Overheating........................ 460Starting........................... 375
Temperature Gauge................... 292
Engine Oil Viscosity...................... 478
Engine Oil Viscosity Chart................. 478
Enhanced Accident Response Feature.......... 77
Entry System, Illuminated.................. 21
Ethanol............................... 436
Event Data Recorder...................... 81
Exhaust Gas Caution.............. 47,96,439,486
Exhaust System....................... 96,486
Exterior Finish Care...................... 500
Exterior Lights.......................... 99
Filters
Air Cleaner......................... 479
Engine Oil......................... 479
Engine Oil Disposal................... 479
FinishCare ............................ 500
Flashers.............................. 460
552 INDEX