2006 JEEP GRAND CHEROKEE fuel

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.
Towing Tips — Cooling System
To reduce potential for engine and transmission over-
heating, take the following actions:
City Driving
When stopped for short periods of time, put transmission
in neutral and increase engine idle speed.
Highway Driving
Reduce speed.
Air Conditioning
Turn off temporarily.
refer 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.
STARTING AND OPERATING 285
5

WARNING!
Jump starting can be dangerous. To avoid personal
injury or damage to electrical components in vehicle,
observe the following warnings:
•Battery fluid is a corrosive acid solution and can burn
or even blind you. Don’t allow battery fluid to contact
your eyes, skin, or clothing. Don’t lean over a battery
when attaching clamps. If acid splashes in eyes or on
skin, flush the area immediately with large amounts of
water.
•Do not use a booster battery or any other booster
source that has a greater than 12–volt system, i.e., do
not use a 24–volt power source.
•Never attempt to jump start a discharged battery that
is frozen, because it could rupture or explode during
jump starting.
•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.
WHAT TO DO IN EMERGENCIES 291
6

MAINTAINING YOUR VEHICLE
CONTENTS

6.1L Engine...........................296

Onboard Diagnostic System — OBD II........297
▫Loose Fuel Filler Cap Message............297

Emissions Inspection And Maintenance
Programs............................298

Replacement Parts......................299

Dealer Service.........................300

Maintenance Procedures..................300
▫Engine Oil..........................301▫Engine Oil Filter......................304
▫Drive Belts — Check Condition And
Tensioner...........................304
▫Spark Plugs.........................305
▫Engine Air Cleaner Filter................305
▫Fuel Filter..........................305
▫Catalytic Converter....................306
▫Maintenance-Free Battery................307
▫Air Conditioner Maintenance.............309
7

▫Power Steering Fluid Check..............310
▫Body Lubrication.....................311
▫Windshield Wiper Blades................312
▫Windshield Washers — Front And Rear.....312
▫Exhaust System......................313
▫Cooling System.......................314
▫Hoses And Vacuum/Vapor Harnesses.......319
▫Brake System........................319
▫Brake Fluid Level Check................321
▫Fuel System Hoses....................322
▫Automatic Transmission................323
▫Front And Rear Wheel Bearings...........324▫Appearance Care And Protection From
Corrosion...........................324

Fuse Panel...........................328
▫Interior Fuses........................328
▫Underhood Fuses (Power Distribution Center) . 330
▫Underhood Fuses (Integrated Power Module) . 332

Vehicle Storage........................334

Replacement Bulbs......................334

Bulb Replacement......................335
▫Head Light..........................335
▫Front Turn Signal.....................337
▫Front Fog Light......................338
▫Rear Tail, Stop, Turn Signal, And Back-Up
Lights.............................339
294 MAINTAINING YOUR VEHICLE

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 297
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” range. Adding one quart of oil
when the reading is at the bottom of the “SAFE” range
will result in an oil level at the top of the “SAFE” range
on these engines.NOTE:Fill engine oil one quart at a time.
Engine Oil Dipstick
MAINTAINING YOUR VEHICLE 301
7

Spark Plugs
Spark plugs must fire properly to assure engine perfor-
mance and emission control. New plugs should be in-
stalled at the specified mileage. The entire set should be
replaced if there is any malfunction due to a faulty spark
plug. Malfunctioning spark plugs can damage the cata-
lytic converter. For proper type of replacement spark
plugs, refer to the “Vehicle Emission Control Informa-
tion” label in the engine compartment.
Engine Air Cleaner Filter
Under normal driving conditions, replace the air filter at
the intervals shown on “Maintenance Schedule A.” If,
however, you drive the vehicle frequently under dusty or
severe conditions, the filter element should be inspected
periodically and replaced if necessary at the intervals
shown on “Maintenance Schedule B.”
WARNING!
The air cleaner can provide a measure of protection
in the case of engine backfire. Do not remove the air
cleaner unless such removal is necessary for repair or
maintenance. Make sure that no one is near the
engine compartment before starting the vehicle with
the air cleaner removed. Failure to do so can result in
serious personal injury.
Fuel Filter
A plugged fuel filter can cause stalling, limit the speed at
which a vehicle can be driven or cause hard starting.
Should an excessive amount of dirt accumulate in the
fuel tank, filter replacement may be necessary. See your
local dealer for service.
MAINTAINING YOUR VEHICLE 305
7

Catalytic Converter
The catalytic converter requires the use of unleaded fuel
only. Leaded gasoline will destroy the effectiveness of the
catalyst as an emission control device.
Under normal operating conditions, the catalytic con-
verter will not require maintenance. However, it is im-
portant to keep the engine properly tuned to assure
proper catalyst operation and prevent possible catalyst
damage.CAUTION!
Damage to the catalytic converter can result if your
vehicle is not kept in proper operating condition. In
the event of engine malfunction, particularly involv-
ing engine misfire or other apparent loss of perfor-
mance, have your vehicle serviced promptly. Contin-
ued operation of your vehicle with a severe
malfunction could cause the converter to overheat,
resulting in possible damage to the converter and the
vehicle.
NOTE:Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
306 MAINTAINING YOUR VEHICLE