service JEEP GRAND CHEROKEE 2009 WK / 3.G Service Manual

If the ignition key is cycled, this sequence will repeat,
providing the system fault still exists. If the system fault
no longer exists, the Tire Pressure Monitoring Telltale
Light will no longer flash, theCHECK TPM SYSTEM
message will not be present, and a pressure value will be
displayed instead of dashes. A system fault can occur by
any of the following:
1. Jamming due to electronic devices or driving next to
facilities emitting the same Radio Frequencies as the TPM
sensors.
2. Installing some form of aftermarket window tinting
that affects radio wave signals.
3. Lots of snow or ice around the wheels or wheel
housings.
4. Using tire chains on the vehicle.
5. Using wheels/tires not equipped with TPM sensors.The EVIC will also display aCHECK TPM SYSTEM
message for three seconds when a system fault is de-
tected possibly related to the trigger component. In this
case, theCHECK TPM SYSTEMmessage is then fol-
lowed by a graphic display, with pressure values still
shown. This indicates the pressure values are still being
received from the TPM Sensors. However, the system still
needs to be serviced as long as theCHECK TPM
SYSTEMmessage exists.
NOTE:
•If your vehicle is equipped with a matching full-size
spare wheel and tire assembly, it has a tire pressure
monitoring sensor, and can be monitored by the Tire
Pressure Monitoring System (TPMS). In the event that
the matching full-size spare tire is swapped with a low
pressure road tire, the next ignition key cycle will still
show the Tire Pressure Monitoring Telltale Light to be
ON, a chime to sound, a Low Pressure message to
appear in the EVIC, and the graphic display will still
STARTING AND OPERATING 353
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for optimum performance. The use of premium gasoline
is not recommended, as it will not provide any benefit
over regular gasoline in these engines.
Light spark knock at low engine speeds is not harmful to
your engine. However, continued heavy spark knock at
high speeds can cause damage and immediate service is
required.
Poor quality gasoline can cause problems such as hard
starting, stalling and hesitations. If you experience these
symptoms, try another brand of gasoline before consid-
ering service for the vehicle.
Over 40 auto manufacturer’s worldwide have issued and
endorsed consistent gasoline specifications (the World-
wide Fuel Charter, WWFC) to define fuel properties
necessary to deliver enhanced emissions, performance,
and durability for your vehicle. The manufacturer recom-
mends the use of gasoline that meets the WWFC speci-
fications, if they are available.Reformulated Gasoline
Many areas of the country require the use of cleaner
burning gasoline referred to as “Reformulated Gasoline.”
Reformulated gasoline contains oxygenates, and are spe-
cifically blended to reduce vehicle emissions and im-
prove air quality.
The manufacturer supports the use of reformulated gaso-
line. Properly blended reformulated gasoline will pro-
vide excellent performance and durability of engine and
fuel system components.
Gasoline/Oxygenate Blends
Some fuel suppliers blend unleaded gasoline with oxy-
genates such as 10% ethanol, MTBE, and ETBE. Oxygen-
ates are required in some areas of the country during the
winter months to reduce carbon monoxide emissions.
Fuels blended with these oxygenates may be used in
your vehicle.
356 STARTING AND OPERATING

blended with MMT provides no performance advantage
beyond gasoline of the same octane number without
MMT. Gasoline blended with MMT reduces spark plug
life and reduces emission system performance in some
vehicles. The manufacturer recommends that gasoline
without MMT be used in your vehicle. The MMT content
of gasoline may not be indicated on the gasoline pump,
therefore, you should ask your gasoline retailer if the
gasoline contains MMT.
It is even more important to look for gasoline without
MMT in Canada, because MMT can be used at levels
higher than those allowed in the United States.
MMT is prohibited in Federal and California reformu-
lated 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 normalconditions 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 performance
and damage the emission 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.
358 STARTING AND OPERATING

FUEL REQUIREMENTS (DIESEL ENGINES)
NOTE: Federal law requires that you must fuel this
vehicle with Ultra Low Sulfur Highway Diesel fuel (15
ppm Sulfur maximum) and prohibits the use of Low
Sulfur Highway Diesel fuel (500 ppm Sulfur maxi-
mum) to avoid damage to the emissions control system.Use good quality diesel fuel from a reputable supplier.
For most year-round service, No. 2 diesel fuel, meeting
ASTM specification D-975 Grade S15, will provide good
performance. If the vehicle is exposed to extreme cold
(below 20° F or -7° C), or is required to operate at
colder-than-normal conditions for prolonged periods,
use climatized No. 2 diesel fuel or dilute the No. 2 diesel
fuel with 50% No. 1 diesel fuel. This will provide better
protection from fuel gelling or wax-plugging of the fuel
filters.
This vehicle is fully-compatible with biodiesel blends
up to 5% biodiesel, meeting ASTM specification D-975.
WARNING!
Do not use alcohol or gasoline as a fuel-blending
agent. They can be unstable under certain conditions
and hazardous or explosive when mixed with diesel
fuel.
Ultra-Low Sulfur Diesel Fuel Label
360 STARTING AND OPERATING

consumption. You can expect your MPG and your driv-
ing range to decrease by about 30% compared to gasoline
operation.
Replacement Parts
All 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.
•Do not use ethanol mixture greater than 85% in
your vehicle. It will cause difficulty in cold start-
ing and may affect drivability.
ADDING FUEL
CAUTION!
DO NOT put gasoline in your diesel vehicle (if
equipped). If you accidentally put gasoline in your
vehicle, DO NOT start the engine. This will cause
damage to the fuel system. Have the fuel system
flushed.
Fuel Filler Cap (Gas Cap)
The gas cap is located behind the 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.
364 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
flashers. When the Hazard Warning flasher 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 flashers.
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, put 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
is on, turn it off. The air conditioning system adds heat to
the engine cooling system and turning off the A/C
removes this heat. You can also turn the temperature
control to maximum heat, the mode control to floor, and
the fan control to high. This allows the heater core to act
as a supplement to the radiator and aids in removing heat
from the engine cooling system.
390 WHAT TO DO IN EMERGENCIES

CAUTION!
Driving with a hot cooling system could damage
your vehicle. If the temperature gauge reads HOT
(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 HOT (H), and you hear continuous
chimes, turn the engine off immediately, and call for
service.
JACKING AND TIRE CHANGING
WARNING!
•Getting under a jacked-up vehicle is dangerous.
The vehicle could slip off the jack and fall on you.
You could be crushed. Never get any part of your
body under a vehicle that is on a jack. If you need
to get under a raised vehicle, take it to a service
center where it can be raised on a lift.
•The jack is designed to be used as a tool for
changing tires only. The jack should not be used to
lift the vehicle for service purposes. The vehicle
should be jacked on a firm, level surface only.
Avoid ice or slippery areas.
WHAT TO DO IN EMERGENCIES 391
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wheel nut tightness is 95 ft lbs (130 N·m). If in doubt
about the correct tightness, have them checked with a
torque wrench by your authorized dealer or at a service
station.
10. Lower the jack to its fully closed position.
WARNING!
A loose tire or jack, thrown forward in a collision or
hard stop could endanger the occupants of the ve-
hicle. Always stow the jack parts and the spare tire in
the places provided.
11. Secure the tire, jack, and tools in their proper loca-
tions.
NOTE:A tire should be stowed with the “beauty” side
up. Storing the tire upside down may result in scratching
or damage to the wheel face. Continue winching up the
tire until you hear the winch “ratchet” three times.Double check to ensure the tire is snug against the
underbody of the vehicle. Damage to the winch cable
may result if the vehicle is driven with the tire loose.
WARNING!
Do not use power tools to winch the tire up or down.
Impact-type tools may damage the winch mecha-
nism.
12. Reinstall the plastic plug into the floor of the cargo
area.
JUMP-STARTING
If the vehicle has a discharged battery, booster cables may
be used to obtain a start from a booster battery or the
battery in another vehicle. This type of start can be
dangerous if done improperly, so follow this procedure
carefully.
398 WHAT TO DO IN EMERGENCIES

MAINTAINING YOUR VEHICLE
CONTENTS
Engine Compartment – 3.7L.............. 406
Engine Compartment – 4.7L.............. 407
Engine Compartment – 5.7L.............. 408
Engine Compartment – 3.0L Diesel......... 409
Onboard Diagnostic System — OBD II...... 410
▫Loose Fuel Filler Cap Message........... 410
Emissions Inspection And Maintenance
Programs............................ 411
Replacement Parts..................... 413Dealer Service........................ 413
Maintenance Procedures................. 413
▫Engine Oil......................... 414
▫Engine Air Cleaner Filter............... 417
▫Maintenance-Free Battery.............. 418
▫Air Conditioner Maintenance............ 419
▫Body Lubrication.................... 420
▫Windshield Wiper Blades............... 421
▫Adding Washer Fluid................. 421
7

ONBOARD DIAGNOSTIC SYSTEM — OBD II
Your vehicle is equipped with a sophisticated onboard
diagnostic system called OBD II. This system monitors
the performance of the emissions, engine, and automatic
transmission control systems. When these systems are
operating properly, your vehicle will provide excellent
performance and fuel economy, as well as engine emis-
sions well within current government regulations.
If any of these systems require service, the OBD II system
will turn on the “Malfunction Indicator Light.” It will
also store diagnostic codes and other information to
assist your service technician in making repairs. Al-
though your vehicle will usually be drivable and not
need towing, see your authorized dealer for service as
soon as possible.CAUTION!
•Prolonged driving with the “Malfunction Indica-
tor Light” on could cause further damage to the
emission control system. It could also affect fuel
economy and drivability. The vehicle must be
serviced before any emissions tests can be per-
formed.
•If the “Malfunction Indicator Light” is flashing
while the engine is running, severe catalytic con-
verter damage and power loss will soon occur.
Immediate service is required.
Loose Fuel Filler Cap Message
After fuel is added, the vehicle diagnostic system can
determine if the fuel filler cap is loose, improperly
installed, or damaged. A “CHECK GASCAP” message
will be displayed in the EVIC (Refer to Section 4 of this
410 MAINTAINING YOUR VEHICLE