light JEEP WRANGLER 2008 JK / 3.G Manual Online

NOTE:If your vehicle is not equipped with a matching
full-size spare wheel and tire assembly, it does not have a
tire pressure monitoring sensor in the spare tire. The
TPMS will not be able to monitor the tire pressure. If you
install the spare tire in place of a road tire that has a
pressure below the low-pressure warning limit, upon the
next ignition key cycle, a chime will sound and the Tire
Pressure Monitoring Telltale Light will turn ON. After
driving the vehicle for up to 10 minutes above 15 mph (25
km/h), the Tire Pressure Monitoring Telltale Light will
flash on and off for 75 seconds and then remain on solid.
For each subsequent ignition key cycle, a chime will
sound and the Tire Pressure Monitoring Telltale Light
will flash on and off for 75 seconds and then remain on
solid. Once you repair or replace the original road tire,
and reinstall it on the vehicle in place of the spare tire, the
TPMS will update automatically and the Tire Pressure
Monitoring Telltale Light will turn OFF, as long as no tire
pressure is below the low-pressure warning limit in any of the four active road tires. The vehicle may need to be
driven for up to 10 minutes above 15 mph (25 km/h) in
order for the TPMS to receive this information.
General Information
This device complies with part 15 of the FCC rules and
RSS 210 of Industry Canada. Operation is subject to the
following conditions:
•This device may not cause harmful interference.
•This device must accept any interference received,
including interference that may cause undesired op-
eration.
The tire pressure sensors are covered under one of the
following licenses:
United States ..................... KR5S120123
Canada ........................ 2671-S120123
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5

FUEL REQUIREMENTS
All engines (except 5.7L engines) are de-
signed to meet all emissions regulations
and provide excellent fuel economy and
performance when using high quality un-
leaded “regular” gasoline having an oc-
tane rating of 87. The use of premium
gasoline is not recommended. Under normal conditions,
the use of premium gasoline will not provide a benefit
over high quality regular gasoline, and in some circum-
stances may result in poorer performance.
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.
336 STARTING AND OPERATING

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-
reformulated 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 are not needed under
normal conditions 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 gasoline is prohibited by Federal
law. Using leaded gasoline can impair engine perfor-
mance, 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.
338 STARTING AND OPERATING

ADDING FUEL
Fuel Filler Cap (Gas Cap)
The gas cap is located on the driver’s side of the vehicle.
If the gas cap is lost or damaged, be sure the replacement
cap is the correct one for this vehicle.
Loose Fuel Filler Cap Message (gASCAP)
After fuel has been added, the vehicle diagnostic system
can determine if the fuel filler cap is possibly loose,
improperly installed, or damaged. If the system detects a
malfunction, the “gASCAP” message will display in the
odometer display. Tighten the gas cap until aclicking
sound is heard. This is an indication that the gas cap is
properly tightened. Press the odometer reset button to
turn the message off. 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. Resolving the problem will turn the MIL
light off.
Fuel Filler Cap
340 STARTING AND OPERATING

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 Malfunction Indicator Light
to illuminate, due to fuel vapors escaping from the
system.
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.
WARNING!
•Never have any smoking materials lit in or near
the vehicle when the gas cap is removed or the
tank filled.
•Never 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.
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 tightened properly, the Malfunction
Indicator Light will come on. Be sure the gas cap is
tightened every time the vehicle is refueled.
STARTING AND OPERATING 341
5

Trailer Hitch Classification
The following chart provides the industry standard for
the maximum trailer weight a given trailer hitch class can
tow and should be used to assist you in selecting the
correct trailer hitch for your intended towing condition.Refer to the Trailer Towing Weights (Maximum Trailer
Weight Ratings) chart for the Max. GTW towable for your
given drivetrain.
Trailer Hitch Classification
Class Max. GTW (Gross Trailer Wt.)
Class I - Light Duty 2,000 lbs (907 kg)
Class II - Medium
Duty 3,500 lbs (1 587 kg)
All trailer hitches should be professionally installed on
your vehicle.
Trailer Towing Weights (Maximum Trailer Weight
Ratings)
The following chart provides the maximum trailer
weight ratings towable for your given drivetrain.
Improper Adjustment of Weight-Distributing System
348 STARTING AND OPERATING

An electronically-actuated trailer brake controller is
required when towing a trailer with electronically
actuated brakes. When towing a trailer equipped with
a hydraulic surge-actuated brake system, an electronic
brake controller is not required.
Trailer brakes are recommended for trailers over 1,000
lbs (454 kg) and required for trailers in excess of 2,000
lbs (907 kg).
CAUTION!
If the trailer weighs more than 1,000 lbs (454 kg)
loaded, it should have its own brakes and they
should be of adequate capacity. Failure to do this
could lead to accelerated brake lining wear, higher
brake pedal effort, and longer stopping distances.
WARNING!
Do not connect trailer brakes to your vehicle’s hy-
draulic brake lines. It can overload your brake sys-
tem and cause it to fail. You might not have brakes
when you need them and could have an accident.
Towing any trailer will increase your stopping dis-
tance. When towing you should allow for additional
space between your vehicle and the vehicle in front
of you. Failure to do so could result in an accident.
Towing Requirements — Trailer Lights & Wiring
Whenever you pull a trailer, regardless of the trailer size,
stop lights and turn signals on the trailer are required for
motoring safety.
356 STARTING AND OPERATING

If using a manual transmission vehicle for trailer towing,
all starts must be in 1st gear to avoid excessive clutch
slippage.
Towing Tips — Automatic Transmission
The DRIVE range can be selected when towing. How-
ever, if frequent shifting occurs while in this range, the
OVERDRIVE range should be selected.
NOTE:Using “O/D OFF” while operating the vehicle
under heavy operating conditions will improve perfor-
mance and extend transmission life by reducing exces-
sive 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. Refer to the “Main-
tenance Schedule” in Section 8 of this manual for trans-
mission fluid change intervals. NOTE:
Check the automatic transmission fluid level
before towing.
Towing Tips — O/D Off
To reduce potential for automatic transmission overheat-
ing, select the “O/D OFF” feature when driving in hilly
areas or shift the transmission to DRIVE position 2 on
more severe grades. Refer to “Transmission Shifting” in
this section.
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.
358 STARTING AND OPERATING

WARNING!
Raising the vehicle higher than necessary can make
the vehicle less stable and cause an accident. It could
slip off the jack and hurt someone near it. Raise the
vehicle only enough to remove the tire.
6. Remove the lug nuts and wheel.
7. Position spare wheel/tire on vehicle and install lug
nuts with cone-shaped end toward wheel. Lightly tighten
nuts clockwise. To avoid the risk of forcing the vehicle off
the jack, do not tighten the nuts fully until the vehicle has
been lowered.
8. Lower the vehicle by turning the jack screw to the left,
and remove the jack and wheel blocks. 9. Finish tightening the lug nuts. Push down on the
wrench while tightening for increased leverage. Alternate
nuts until each nut has been tightened twice. Correct
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. Remove jack assembly and wheel blocks.
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.
370 WHAT TO DO IN EMERGENCIES

▫Driveline And Steering Component
Lubrication ..........................392
▫ Body Lubrication .....................392
▫ Windshield Wiper Blades ................392
▫ Windshield And Rear Window Washers .....393
▫ Exhaust System ......................393
▫ Cooling System .......................394
▫ Hoses And Vacuum/Vapor Harnesses .......399
▫ Brake System ........................399
▫ Automatic Transmission ................401
▫ Hydraulic Clutch Fluid — Manual
Transmission ........................403
▫ Manual Transmission ..................403
▫ Transfer Case ........................404 ▫
Front/Rear Axle Fluid ..................405
▫ Maintenance After Off-Road Driving ........405
▫ Appearance Care And Protection From
Corrosion ...........................406
 Fuses (Totally Integrated Power Module) ......413
 Vehicle Storage ........................419
 Replacement Bulbs — If Equipped ...........420
 Bulb Replacement ......................420
▫ Head Light ..........................420
▫ Front Park/Turn Signal .................421
▫ Front Side Marker .....................422
▫ Front Fog Light ......................422
▫ Rear Tail, Stop, Turn Signal, And Backup
Lights .............................422
376 MAINTAINING YOUR VEHICLE