2012 JEEP GRAND CHEROKEE maintenance

and/or the flow rate is reduced. If you must cross
flowing water avoid depths in excess of 9 inches (23 cm).
The flowing water can erode the streambed, causing your
vehicle to sink into deeper water. Determine exit point(s)
that are downstream of your entry point to allow for
drifting.
Standing Water
Avoid driving in standing water deeper than 20 inches
(51 cm), and reduce speed appropriately to minimize
wave effects. Maximum speed in 20 inches (51 cm) of
water is less than 5 mph (8 km/h).
Maintenance
After driving through deep water, inspect your vehicle
fluids and lubricants (engine oil, transmission oil, axle,
transfer case) to assure the fluids have not been contami-
nated. Contaminated fluid (milky, foamy in appearance)
should be flushed/changed as soon as possible to pre-
vent component damage.Driving In Snow, Mud And Sand
In heavy snow, when pulling a load, or for additional
control at slower speeds, shift the transmission to a low
gear and shift the transfer case to 4WD LOW if necessary.
Refer to “Four-Wheel Drive Operation” in “Starting and
Operating” for further information. Do not shift to a
lower gear than necessary to maintain forward motion.
Over-revving the engine can spin the wheels and traction
will be lost.
Avoid abrupt downshifts on icy or slippery roads, because
engine braking may cause skidding and loss of control.
Hill Climbing
NOTE:Before attempting to climb a hill, determine the
conditions at the crest and/or on the other side.
Before climbing a steep hill, shift the transmission to a
lower gear and shift the transfer case to 4WD LOW. Use
first gear and 4WD LOW for very steep hills.
456 STARTING AND OPERATING

These effects can be reduced by timely rotation of tires.
The benefits of rotation are especially worthwhile with
aggressive tread designs such as those on On/Off-Road
type tires. Rotation will increase tread life, help to main-
tain mud, snow, and wet traction levels, and contribute to
a smooth, quiet ride.
Refer to the “Maintenance Schedule” for the proper
maintenance intervals. More frequent rotation is permis-
sible if desired. The reasons for any rapid or unusual
wear should be corrected prior to rotation being per-
formed.
NOTE:The premium Tire Pressure Monitor System will
automatically locate the pressure values displayed in the
correct vehicle position following a tire rotation.
The suggested rotation method is the “forward-cross”
shown in the following diagram.
TIRE PRESSURE MONITOR SYSTEM (TPMS)
The Tire Pressure Monitoring System (TPMS) will warn
the driver of a low tire pressure based on the vehicle
recommended cold tire placard pressure.
The tire pressure will vary with temperature by about
1 psi (7 kPa) for every 12°F (6.5°C). This means that when
Tire Rotation
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Light will still be ON. In this situation, the Tire Pressure
Monitoring Telltale Light will turn OFF only after the
tires have been inflated to the vehicle’s recommended
cold tire pressure value.
CAUTION!
•The TPMS has been optimized for the original
equipment tires and wheels. TPMS pressures have
been established for the tire size equipped on your
vehicle. Undesirable system operation or sensor
damage may result when using replacement
equipment that is not of the same size, type, and/or
style. Aftermarket wheels can cause sensor dam-
age. Do not use aftermarket tire sealants or balance
beads if your vehicle is equipped with a TPMS, as
damage to the sensors may result.(Continued)
CAUTION! (Continued)
•After inspecting or adjusting the tire pressure
always reinstall the valve stem cap. This will
prevent moisture and dirt from entering the valve
stem, which could damage the Tire Pressure Moni-
toring Sensor.
NOTE:
•The TPMS is not intended to replace normal tire care
and maintenance, or to provide warning of a tire
failure or condition.
•The TPMS should not be used as a tire pressure gauge
while adjusting your tire pressure.
•Driving on a significantly under-inflated tire causes
the tire to overheat and can lead to tire failure.
Under-inflation also reduces fuel efficiency and tire
tread life, and may affect the vehicle’s handling and
stopping ability.
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STARTING AND OPERATING 501

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.(Continued)
WARNING! (Continued)
•Guard against carbon monoxide with proper
maintenance. Have the exhaust system inspected
every time the vehicle is raised. Have any abnor-
mal conditions repaired promptly. Until repaired,
drive with all side windows fully open.
•Keep the liftgate closed when driving your vehicle
to prevent carbon monoxide and other poisonous
exhaust gases from entering the vehicle.
FLEXIBLE FUEL (3.6L ENGINE ONLY) — IF
EQUIPPED
E-85 General Information
The information in this section is for Flexible Fuel ve-
hicles only. These vehicles can be identified by a unique
fuel filler door label that statesEthanol (E-85) or Un-
leaded Gasoline Only. This section only covers those
subjects that are unique to these vehicles. Please refer to
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STARTING AND OPERATING 513

Cruising Range
Because E-85 fuel contains less energy per gallon/liter
than gasoline, you will experience an increase in fuel
consumption. You can expect your miles per gallon
(mpg)/miles per liter and your driving range to decrease
by about 30%, compared to gasoline operation.
Replacement Parts
Many components in your Flexible Fuel Vehicle (FFV) are
designed to be compatible with ethanol. Always be sure
that your vehicle is serviced with correct ethanol com-
patible parts.
CAUTION!
Replacing fuel system components with non-ethanol
compatible components can damage your vehicle.
Maintenance
CAUTION!
Do not use ethanol mixture greater than 85% in your
vehicle. It will cause difficulty in cold starting and
may affect driveability.
ADDING FUEL
Fuel Filler Cap (Gas Cap)
The gas cap is located behind the locking fuel filler door,
on the driver’s side of the vehicle. If the gas cap is lost or
damaged, be sure the replacement cap is for use with this
vehicle.
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STARTING AND OPERATING 517

NOTE:Remember that everything put into or on the
trailer adds to the load on your vehicle. Also, additional
factory-installed options, or authorized dealer-installed
options, must be considered as part of the total load on
your vehicle. Refer to “Tire Safety Information/Tire and
Loading Information Placard” in “Starting and Operat-
ing” for further information.
Towing Requirements
To promote proper break-in of your new vehicle drive-
train components, the following guidelines are recom-
mended.
CAUTION!
•Do not tow a trailer at all during the first 500 miles
(805 km) the new vehicle is driven. The engine,
axle or other parts could be damaged.
(Continued)
CAUTION! (Continued)
•Then, during the first 500 miles (805 km) that a
trailer is towed, do not drive over 50 mph
(80 km/h) and do not make starts at full throttle.
This helps the engine and other parts of the
vehicle wear in at the heavier loads.
Perform the maintenance listed in the “Maintenance
Schedule.” Refer to “Maintenance Schedule” for the
proper maintenance intervals. When towing a trailer,
never exceed the GAWR or GCWR ratings.
WARNING!
Improper towing can lead to a collision. Follow these
guidelines to make your trailer towing as safe as
possible: (Continued)
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STARTING AND OPERATING 531

Towing Tips
Before setting out on a trip, practice turning, stopping
and backing the trailer in an area away from heavy
traffic.
Automatic Transmission
The DRIVE range can be selected when towing. How-
ever, if frequent shifting occurs while in this range, the
TOW/HAUL mode (if equipped), or a lower gear range,
should be selected.
NOTE:Using the TOW/HAUL mode (if equipped) or
selecting a lower gear range (using the Electronic Range
Select (ERS) feature) while operating the vehicle under
heavy operating conditions, will improve performance
and extend transmission life by reducing excessive shift-
ing and heat buildup. This action will also provide better
engine braking. The transmission fluid and filter should be changed if
you REGULARLY tow a trailer for more than 45 minutes
of continuous operation. Refer to “Maintenance Sched-
ule” for the proper maintenance intervals.
NOTE:
Check the transmission fluid level before towing
(5.7L engine).
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.
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MAINTAINING YOUR VEHICLE
CONTENTS
Engine Compartment — 3.6L ............. 573
 Engine Compartment — 5.7L ............. 574
 Onboard Diagnostic System – OBD II ....... 575
▫ Loose Fuel Filler Cap Message ........... 575
 Emissions Inspection And Maintenance
Programs ............................ 576
 Replacement Parts ..................... 577
 Dealer Service ........................ 578
 Maintenance Procedures ................. 578
▫ Engine Oil ......................... 579 ▫
Engine Oil Filter ..................... 582
▫ Engine Air Cleaner Filter ............... 582
▫ Maintenance-Free Battery .............. 583
▫ Air Conditioner Maintenance ............ 585
▫ Body Lubrication .................... 586
▫ Windshield Wiper Blades ............... 586
▫ Adding Washer Fluid ................. 588
▫ Exhaust System ..................... 589
▫ Cooling System ..................... 592
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