2008 JEEP GRAND CHEROKEE fuel

CAUTION!
Damage to the fuel system or emission control sys-
tem could result from using an improper fuel cap
(gas cap). A poorly fitting cap could let impurities
into the fuel system. Also, a poorly fitting after-
market cap can cause the MIL (Malfunction Indicator
Light) to illuminate, due to fuel vapors escaping from
the system.
CAUTION!
A poorly fitting gas cap may cause the Malfunction
Indicator Light to turn on.
CAUTION!
To avoid fuel spillage and overfilling, do not ªtop
offº the fuel tank after filling.
NOTE:When the fuel nozzle ªclicksº or shuts off, the
fuel tank is full.
WARNING!
²Never have any smoking materials lit in or near
the vehicle when the gas cap is removed or the
tank filled.
²Never add fuel when the engine is running. This is
in violation of most state and federal fire regula-
tions and will cause the malfunction indicator
light to turn on.
STARTING AND OPERATING 283
5

NOTE:Tighten the gas cap about 1/4 turn until you
hear one click. This is an indication that cap is properly
tightened.
If the gas cap is not tighten properly, the Malfunction
Indicator Light will come on. Be sure the gas cap is
tightened every time the vehicle is refueled.
WARNING!
A fire may result if gasoline is pumped into a
portable container that is inside of a vehicle. You
could be burned. Always place gas containers on the
ground while filling.
Loose Fuel Filler Cap Message
If the vehicle diagnostic system determines that the fuel
filler cap is loose, improperly installed, or damaged, a
ªCHECK GASCAPº message will be displayed in the
EVIC (Electronic Vehicle Information Center). Refer to
ªElectronic Vehicle Information Centerº in Section 4 of
this manual. Tighten the fuel filler cap until a ªclickingº
sound is heard. This is an indication that the fuel filler
cap is properly tightened. Refer to ªOnboard Diagnostic
System Ð OBDIIº in Section 7 of this manual for more
information.
CAUTION!
Damage to the fuel system or emission control sys-
tem could result from using an improper fuel tank
filler cap (gas cap). A poorly fitting cap could let
impurities into the fuel system.
284 STARTING AND OPERATING

WARNING!
²Never add fuel when the engine is running.
²Never have any smoking materials lit in or near
the vehicle when the fuel cap is removed or the
tank filled.
TRAILER TOWING
In this section you will find safety tips and information
on limits to the type of towing you can reasonably do
with your vehicle. Before towing a trailer carefully re-
view this information to tow your load as efficiently and
safely as possible.
To maintain warranty coverage, follow the requirements
and recommendations in this manual concerning ve-
hicles used for trailer towing.
Common Towing Definitions
The following trailer towing related definitions will assist
you in understanding the following information:
Gross Vehicle Weight Rating (GVWR)
The GVWR is the total allowable weight of your vehicle.
This includes driver, passengers, cargo and tongue
weight. The total load must be limited so that you do not
exceed the GVWR.
Gross Trailer Weight (GTW)
The gross trailer weight (GTW) is the weight of the trailer
plus the weight of all cargo, consumables and equipment
(permanent or temporary) loaded in or on the trailer in its
9loaded and ready for operation9condition. The recom-
mended way to measure GTW is to put your fully loaded
trailer on a vehicle scale. The entire weight of the trailer
must be supported by the scale.
STARTING AND OPERATING 285
5

Towing Tips Ð Electronic Speed Control (If
Equipped)
þ
Don't use in hilly terrain or with heavy loads.
þWhen 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.
þUse speed control in flat terrain and with light loads to
maximize fuel efficiency.
Towing Tips Ð Cooling System
To reduce potential for engine and transmission over-
heating, take the following actions:
þCity Driving
When stopped for short periods of time, put transmission
in neutral and increase engine idle speed.
þHighway Driving
Reduce speed.
þAir Conditioning
Turn off temporarily.
þrefer to Cooling System Operating information in the
Maintenance section of this manual for more informa-
tion.
RECREATIONAL TOWING (BEHIND
MOTORHOME, ETC.)
Recreational towing is not allowed.
296 STARTING AND OPERATING

MAINTAINING YOUR VEHICLE
CONTENTS
mEngine Compartment ± 6.1L...............306
mOnboard Diagnostic System Ð OBD II........307
NLoose Fuel Filler Cap Message............308
mEmissions Inspection And Maintenance
Programs............................308
mReplacement Parts......................310
mDealer Service.........................310
mMaintenance Procedures..................311
NEngine Oil..........................311NEngine Oil Filter......................315
NDrive Belts Ð Check Condition And
Tensioner...........................315
NSpark Plugs.........................316
NEngine Air Cleaner Filter................316
NFuel Filter..........................317
NCatalytic Converter....................317
NMaintenance-Free Battery................318
NAir Conditioner Maintenance.............319
7

NPower Steering Fluid Check..............320
NBody Lubrication.....................321
NWindshield Wiper Blades................322
NWindshield Washers Ð Front And Rear.....322
NExhaust System......................323
NCooling System.......................324
NHoses And Vacuum/Vapor Harnesses.......329
NBrake System........................329
NBrake Fluid Level Check................331
NFuel System Hoses....................332
NAutomatic Transmission................333
NFront And Rear Wheel Bearings...........333NAppearance Care And Protection From
Corrosion...........................333
mFuse Panel...........................338
NInterior Fuses........................338
NUnderhood Fuses (Power Distribution
Center)............................341
NUnderhood Fuses (Integrated Power
Module)............................344
mVehicle Storage........................345
mReplacement Bulbs......................346
mBulb Replacement......................347
NHigh Intensity Discharge Headlights (HID) Ð
If Equipped.........................347
NHead Light..........................347
304 MAINTAINING YOUR VEHICLE

ONBOARD DIAGNOSTIC SYSTEM Ð 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 ªMalfunction Indicator Light.º 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 dealer for service as soon as
possible.CAUTION!
²Prolonged driving with the ªMalfunction Indica-
tor Lightº on could cause further damage to the
emission control system. It could also affect fuel
economy and driveability. The vehicle must be
serviced before any emissions tests can be per-
formed.
²If the ªMalfunction Indicator Lightº is flashing
while the engine is running, severe catalytic con-
verter damage and power loss will soon occur.
Immediate service is required.
MAINTAINING YOUR VEHICLE 307
7

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 ªCHECK GASCAPº message
will be displayed in the EVIC (Refer to Section 4 of this
manual). Tighten the gas cap until a9clicking9sound is
heard. This is an indication that the gas cap is properly
tightened.
This message may be temporarily overridden by pressing
either the C/T, STEP, or MENU buttons. However, after
one minute of no customer interaction, the EVIC will
display again the ªCHECK GASCAPº message. The
message will remain displayed until the vehicle diagnos-
tic system can retest the fuel system. The test will
perform the next time the vehicle is started, if the vehicle
was keyed off above 40ÉF (4ÉC) outside temperature and
the following vehicle start is above 40ÉF (4ÉC) outsidetemperature. It may be possible to have a message that
will not clear due to the test being disabled due to low
outside temperatures. If the test is performed and the
problem is gone, the message will disappear.
If the problem persists, the message will appear the next
time the vehicle is started. This might indicate a damaged
cap. If the problem is detected twice in a row, the system
will turn on the Malfunction Indicator Light (MIL).
Resolving the problem will turn the MIL light off. See
your authorized dealer for service.
EMISSIONS INSPECTION AND MAINTENANCE
PROGRAMS
In some localities, it may be a legal requirement to pass
an inspection of your vehicle's emissions control system.
Failure to pass could prevent vehicle registration.
308 MAINTAINING YOUR VEHICLE