2006 JEEP GRAND CHEROKEE fuel

•Guard against carbon monoxide with proper mainte-
nance. Have the exhaust system inspected every time
the vehicle is raised. Have any abnormal 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 ex-
haust gases from entering the vehicle.
FUEL TANK FILLER CAP (GAS CAP)
The fuel cap is located on the left side of the vehicle. If the
fuel cap is lost or damaged, be sure the replacement cap
is for use with this vehicle.
Fuel Filler Cap Location
306 STARTING AND OPERATING

CAUTION!
Damage to the fuel system or emission control
system 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 Indica-
tor Light) to illuminate, due to fuel vapors escaping
from the system.
•Turn the engine off.
•Rotate the fuel cap to the left to remove.
•To replace the cap, insert it into the filler neck and
tighten the cap about 1/4 turn until you hear one click.
This is an indication that the cap is properly tightened.
•Make sure that the fuel cap tether strap is not caught
under the fuel cap.
CAUTION!
To avoid fuel spillage and overfilling, do not“top
off”the fuel tank after filling.
NOTE:When the fuel nozzle“clicks”or shuts off, the
fuel tank is full.
Loose Fuel Filler Cap Message
If the vehicle diagnostic system determines that the fuel
filler cap is loose, improperly installed, or damaged, a
“CHECK GAS CAP”message will be displayed in the
EVIC (Electronic Vehicle Information Center). Refer to
“Electronic Vehicle Information Center”in Section 4 of this
manual. Tighten the fuel filler cap properly and press the
odometer reset button to turn the message off. If the
problem continues, the message will appear the next time
the vehicle is started. Refer to“Onboard Diagnostic System
—OBDII”in Section 7 of this manual for more information.
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WARNING!
•Remove the fuel cap (gas cap) slowly to prevent
fuel spray from the filler neck which may cause
injury.
•The volatility of some gasoline may cause a
buildup of pressure in the fuel tank that may
increase while you drive. This pressure can result
in a spray of gasoline and/or vapors when the cap
is removed from a hot vehicle. Removing the cap
slowly allows the pressure to vent and prevents
fuel spray.
•Never have any smoking materials lit in or near
the vehicle when the fuel cap is removed or the
tank filled.
•Never add fuel to the vehicle when the engine is
running.
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.
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.
308 STARTING AND OPERATING

If using a manual transmission vehicle for trailer towing,
all starts must be in FIRST gear to avoid excessive clutch
slippage.
Towing Tips—Automatic Transmission
The“D”range can be selected when towing. However, if
frequent shifting occurs while in this range, the”Tow/
Haul”mode (if equipped) or the“3”range should be
selected. Shift the transmission to Drive position 2 on
more severe grades.
NOTE:Using the”Tow/Haul”mode (if equipped) or
the“3”range while operating the vehicle under heavy
operating conditions will improve performance and ex-
tend transmission life by reducing excessive 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. See Schedule“B”in
section 8 of this manual for transmission fluid change
intervals.
NOTE:Check the automatic transmission fluid level
before towing.
Towing Tips—Electronic Speed Control (If
Equipped)

Don’t 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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5

•Be sure your vehicle is not touching the jump start
vehicle.
•Observe all Battery Warnings in Section 7 of this
manual, while jump starting your vehicle.
WARNING!
Do not attempt to push or tow your vehicle to get it
started. Unburned fuel could enter the catalytic
converter and, once the engine has started, ignite and
damage the converter and vehicle.
EMERGENCY TOW HOOKS—IF EQUIPPED
If your vehicle is equipped with tow hooks, there will be
one in the rear and two mounted on the front of the
vehicle. The rear hook will be located on the driver’s side
of the vehicle.
NOTE:For off-road recovery, it is recommended to use
both of the front tow hooks to minimize the risk of
damage to the vehicle.
CAUTION!
Tow hooks are for emergency use only, to rescue a
vehicle stranded off road. Do not use tow hooks for
tow truck hookup or highway towing. You could
damage your vehicle.
338 WHAT TO DO IN EMERGENCIES

MAINTAINING YOUR VEHICLE
CONTENTS

3.7L Engine...........................344

4.7L Engine...........................345

5.7L Engine...........................346

Onboard Diagnostic System—OBDII........347
▫Loose Fuel Filler Cap Message............347

Emissions Inspection And Maintenance
Programs............................348

Replacement Parts......................349

Dealer Service.........................350
Maintenance Procedures..................350
▫Engine Oil..........................351
▫Drive Belts—Check Condition And
Tensioner...........................354
▫Spark Plugs.........................355
▫Catalytic Converter....................355
▫Crankcase Emission Control System........357
▫Air Cleaner Filter.....................358
▫Maintenance-Free Battery................358
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 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 driveability. 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 loose fuel filler cap message will
be displayed in the instrument cluster. Tighten the gas
MAINTAINING YOUR VEHICLE 347
7

could adversely affect the engine or vehicle performance.
These items should be inspected if a malfunction is
observed or suspected.
Engine Oil
Checking Oil Level
To assure proper engine lubrication, the engine oil must
be maintained at the correct level. Check the oil level at
regular intervals, such as every fuel stop.
The best time to check the engine oil level is about 5
minutes after a fully warmed engine is shut off or before
starting the engine after it has sat overnight.
Checking the oil while the vehicle is on level ground will
improve the accuracy of the oil level readings. Maintain
the oil level in the SAFE level range. Adding 1 U.S. Quart
(0.95L) of oil when the level is at the bottom of the SAFE
range will result in the level being at the top of the SAFE
range.
CAUTION!
Overfilling or underfilling the crankcase will cause
aeration or loss of oil pressure. This could damage
your engine.
Change Engine Oil
Road conditions as well as your kind of driving affect the
interval at which your oil should be changed. Check the
following to determine if any apply to you:
•Day or night temperatures are below 32°F(0°C)
•Stop and go driving
•Extensive engine idling
•Driving in dusty conditions
•Short trips of less than 10 miles (16.2 km)
MAINTAINING YOUR VEHICLE 351
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