ECU JEEP WRANGLER UNLIMITED 2013 Workshop Manual

The Basics Of Off-Road Driving
You will encounter many types of terrain driving off-
road. You should be familiar with the terrain and area
before proceeding. There are many types of surface
conditions: hard-packed dirt, gravel, rocks, grass, sand,
mud, snow and ice. Every surface has a different effect on
your vehicle’s steering, handling and traction. Control-
ling your vehicle is one of the keys to successful off-road
driving, so always keep a firm grip on the steering wheel
and maintain a good driving posture. Avoid sudden
accelerations, turns or braking. In most cases, there are no
road signs, posted speed limits or signal lights. Therefore,
you will need to use your own good judgment on what is
safe and what is not. When on a trail, you should always
be looking ahead for surface obstacles and changes in
terrain. The key is to plan your future driving route while
remembering what you are currently driving over. CAUTION!Never park your vehicle over dry grass or other
combustible materials. The heat from your vehicle
exhaust system could cause a fire.
WARNING!Always wear your seat belt and firmly tie down
cargo. Unsecured cargo can become projectiles in an
off-road situation.
When To Use 4L (Low) Range
When off-road driving, shift into 4L (Low) for additional
traction and control on slippery or difficult terrain,
ascending or descending steep hills, and to increase low
speed pulling power. This range should be limited to438 STARTING AND OPERATING

items down low and be sure that the weight is distributed
equally. Stow all loose items securely before driving.
Improper weight distributions can have an adverse effect
on the way your vehicle steers and handles and the way
the brakes operate.
CAUTION!Do not load your vehicle any heavier than the GVWR
or the maximum front and rear GAWR. If you do,
parts on your vehicle can break, or it can change the
way your vehicle handles. This could cause you to
lose control. Also overloading can shorten the life of
your vehicle. 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
review 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
5 STARTING AND OPERATING 515

WARNING!Improper towing can lead to a collision. Follow these
guidelines to make your trailer towing as safe as
possible:
• Make certain that the load is secured in the trailer
and will not shift during travel. When trailering
cargo that is not fully secured, dynamic load shifts
can occur that may be difficult for the driver to
control. You could lose control of your vehicle and
have a collision.
• When hauling cargo or towing a trailer, do not
overload your vehicle or trailer. Overloading can
cause a loss of control, poor performance or dam-
age to the brakes, axle, engine, transmission, steer-
ing, suspension, chassis structure or tires. (Continued) WARNING! (Continued)• Safety chains must always be used between your
vehicle and trailer. Always connect the chains to
the frame or hook retainers of the vehicle hitch.
Cross the chains under the trailer tongue and allow
enough slack for turning corners.
• Vehicles with trailers should not be parked on a
grade. When parking, apply the parking brake on
the tow vehicle. Put the tow vehicle automatic
transmission in PARK. With a manual transmis-
sion, shift the transmission into first gear. And
with four-wheel-drive vehicles, make sure the
transfer case is not in N (Neutral). Always, block or
 chock  the trailer wheels.
• GCWR must not be exceeded. (Continued)526 STARTING AND OPERATING

Jacking Instructions
WARNING!Carefully follow these tire changing warnings to
help prevent personal injury or damage to your
vehicle:
• Always park on a firm, level surface as far from the
edge of the roadway as possible before raising the
vehicle.
• Turn on the Hazard Warning flasher.
• Block the wheel diagonally opposite the wheel to
be raised.
• Set the parking brake firmly and set an automatic
transmission in PARK; a manual transmission in
REVERSE.
• Never start or run the engine with the vehicle on a
jack. (Continued) WARNING! (Continued)• Do not let anyone sit in the vehicle when it is on a
jack.
• Do not get under the vehicle when it 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.
• Only use the jack in the positions indicated and for
lifting this vehicle during a tire change.
• If working on or near a roadway, be extremely
careful of motor traffic.
• To assure that spare tires, flat or inflated, are
securely stowed, spares must be stowed with the
valve stem facing the ground.
6 WHAT TO DO IN EMERGENCIES 543

10. Remove the jack assembly and wheel blocks.
11 . Secure the tire, jack, and tools in their proper locations.
12. Remove blocks from wheels.
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.
Road Tire Installation
1. Mount the road tire on the axle.
2. Install the remaining lug nuts with the cone shaped
end of the nut toward the wheel. Lightly tighten the
lug nuts. WARNING!To avoid the risk of forcing the vehicle off the jack,
do not tighten the lug nuts fully until the vehicle has
been lowered. Failure to follow this warning may
result in personal injury.
3. Lower the vehicle to the ground by turning the jack
handle counterclockwise.
4. Finish tightening the lug nuts. Push down on the
wrench while at the end of the handle for increased
leverage. Tighten the lug nuts in a star pattern until each
nut has been tightened twice. The correct tightness of
each lug nut 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 service station.
5. After 25 miles (40 km) check the lug nut torque with a
torque wrench to ensure that all lug nuts are properly
seated against the wheel.
6 WHAT TO DO IN EMERGENCIES 547

Proper towing or lifting equipment is required to prevent
damage to your vehicle. Use only tow bars and other
equipment designed for this purpose, following equip-
ment manufacturer ’s instructions. Use of safety chains is
mandatory. Attach a tow bar or other towing device to
main structural members of the vehicle, not to bumpers
or associated brackets. State and local laws regarding
vehicles under tow must be observed.
If you must use the accessories (wipers, defrosters, etc.)
while being towed, the ignition must be in the ON/RUN
position, not the ACC position.
If the vehicle’s battery is discharged, refer to “Shift Lever
Override” in “What To Do In Emergencies” for instruc-
tions on shifting the automatic transmission out of PARK
for towing. CAUTION!Do not use sling type equipment when towing. When
securing the vehicle to a flatbed truck, do not attach to
front or rear suspension components. Damage to your
vehicle may result from improper towing.
Without The Ignition Key
Special care must be taken when the vehicle is towed
with the ignition in the OFF position. The only approved
method of towing without the key fob is with a flatbed
truck. Proper towing equipment is necessary to prevent
damage to the vehicle.
6 WHAT TO DO IN EMERGENCIES 557

WARNING!• Use only manufacturer’s recommended brake
fluid. Refer to “Fluids, Lubricants, and Genuine
Parts” in “Maintaining Your Vehicle” for further
information. Using the wrong type of brake fluid
can severely damage your brake system and/or
impair its performance. The proper type of brake
fluid for your vehicle is also identified on the
original factory installed hydraulic master cylinder
reservoir.
• To avoid contamination from foreign matter or
moisture, use only new brake fluid or fluid that has
been in a tightly closed container. Keep the master
cylinder reservoir cap secured at all times. Brake
fluid in a open container absorbs moisture from the
air resulting in a lower boiling point. This may (Continued) WARNING! (Continued)cause it to boil unexpectedly during hard or pro-
longed braking, resulting in sudden brake failure.
This could result in a collision.
• Overfilling the brake fluid reservoir can result in
spilling brake fluid on hot engine parts, causing
the brake fluid to catch fire. Brake fluid can also
damage painted and vinyl surfaces, care should be
taken to avoid its contact with these surfaces.
• Do not allow petroleum based fluid to contaminate
the brake fluid. Brake seal components could be
damaged, causing partial or complete brake failure.
This could result in a collision.584 MAINTAINING YOUR VEHICLE

ABS (Anti-Lock Brake System) ............... .303
Adding Engine Coolant (Antifreeze) ........... .579
Adding Fuel ............................ .510
Additives, Fuel .......................... .509
Airbag ..................................62
Airbag Deployment ........................71
Airbag Light .............................74
Airbag Maintenance ........................73
Airbag, Side ..............................70
Air Cleaner, Engine (Engine Air Cleaner Filter) . . . .569
Air Conditioner Maintenance ................ .571
Air Conditioning ......................... .392
Air Conditioning Controls .................. .392
Air Conditioning Filter .................... .402
Air Conditioning, Operating Tips ............. .403
Air Conditioning Refrigerant ................ .571
Air Conditioning System ................... .392
Air Pressure, Tires ........................ .483
Alarm Light ............................ .305 Alarm (Security Alarm) ......................19
Alterations/Modifications, Vehicle ...............9
Antenna, Satellite Radio .................... .352
Antifreeze (Engine Coolant) ................. .578
Disposal ............................ .581
Anti-Lock Brake System (ABS) ............... .455
Anti-Lock Warning Light ................... .303
Appearance Care ........................ .591
Arming Theft System (Security Alarm) ...........20
Assistance Towing ........................ .130
Auto Down Power Windows ..................42
Automatic Door Locks ......................39
Automatic Headlights ..................... .168
Automatic Oil Change Indicator .............. .325
Automatic Temperature Control (ATC) ......... .396
Automatic Transmission ................... .420
Adding Fluid ........................ .588
Fluid and Filter Changes ................ .588
Fluid Change ........................ .588634 INDEX

Illuminated Entry .......................21
Instrument Cluster ..................... .167
Interior ............................. .171
Lights On Reminder .................... .170
Low Fuel ........................... .300
Oil Pressure ......................... .301
Passing ............................. .170
Rear Servicing ........................ .609
Rear Tail ............................ .609
Seat Belt Reminder ..................... .301
Security Alarm (Theft Alarm) ............. .305
Service ............................. .607
Side Marker ......................... .609
Theft Alarm (Security Alarm) ............. .305
Tire Pressure Monitoring (TPMS) ........... .306
Traction Control ....................... .468
Turn Signal .......................... .103
Voltage ............................. .300
Warning (Instrument Cluster Description) .... .300 Loading Vehicle ......................... .513
Tires ............................... .477
Locking Axle ........................... .433
Locks ..................................36
Automatic Door ........................39
Child Protection ........................40
Door ................................36
Power Door ...........................38
Lubrication, Body ........................ .572
Maintenance Free Battery ................... .570
Maintenance Procedures ................... .565
Maintenance Schedule ..................... .614
Malfunction Indicator Light (Check Engine) .......311
Manual, Service ......................... .630
Manual Transmission ..................... .414
Fluid Level Check ..................... .589
Lubricant Selection ..................... .588
Shift Speeds ......................... .415
10 INDEX 643

Adjustable Upper Shoulder Anchorage ........55
And Pregnant Women ....................61
Child Restraint .........................76
Extender ..............................61
Front Seat .............................48
Inspection ........................... .101
Pretensioners ..........................59
Reminder ........................... .301
Untwisting Procedure ....................55
Seats ................................. .152
Adjustment .......................... .152
Easy Entry .......................... .155
Fold and Tumble Rear .................. .161
Heated ............................. .159
Height Adjustment ..................... .154
Rear Folding ......................... .164
Removal ............................ .163
Seatback Release ...................... .154
Tilting .............................. .154 Security Against Theft .......................19
Security Alarm (Theft Alarm) ..................19
Sentry Key (Immobilizer) ....................16
Sentry Key Programming ....................18
Sentry Key Replacement .....................17
Service Assistance ........................ .625
Service Contract ......................... .627
Service Manuals ......................... .630
Settings, Personal ........................ .331
Setting the Clock ......................... .337
Shifting ............................... .418
Automatic Transmission ................. .418
Manual Transmission ................... .414
Transfer Case, Shifting into Transfer Case
Neutral (N) .......................... .534
Transfer Case, Shifting out of Transfer Case
Neutral (N) .......................... .536
Shift Lever Override ...................... .554
Shoulder Belts ............................48
10 INDEX 647