service JEEP WRANGLER 2005 TJ / 2.G Owner's Manual

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.
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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.
For states which have an I/M (Inspection and
Maintenance) requirement, this check verifies the
following: the MIL (Malfunction Indicator Lamp)
is functioning and is not on when the engine is running,
and that the OBD (On Board Diagnostic) system is ready
for testing.
Normally, the OBD system will be ready. The OBD
system maynotbe ready if your vehicle was recently
serviced, if you recently had a dead battery, or a battery
replacement. If the OBD system should be determined
not ready for the I/M test, your vehicle may fail the test.Your vehicle has a simple ignition key actuated test
which you can use prior to going to the test station. To
check if your vehicle’s OBD system is ready, you must do
the following:
1. Insert your ignition key into the ignition switch.
2. Turn the ignition to the ON position, but do not crank
or start the engine.
3. If you crank or start the engine, you will have to start
this test over.
4. As soon as you turn your key to the ON position, you
will see your MIL symbol come on as part of a normal
bulb check.
5. Approximately 15 seconds later, one of two things will
happen:
a. The MIL will flash for about 10 seconds and then
return to being fully illuminated until you turn off the
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ignition key or start the engine. This means that your
vehicle’s OBD system isnot readyand you shouldnot
proceed to the I/M station.
b. The MIL will not flash at all and will remain fully
illuminated until you turn off the ignition key or start
the engine. This means that your vehicle’s OBD system
isreadyand you can proceed to the I/M station.
If your OBD system isnot ready,you should see your
authorized dealer or repair facility. If your vehicle was
recently serviced or had a battery failure or replacement,
you may need to do nothing more than drive your
vehicle as you normally would in order for your OBD
system to update. A recheck with the above test routine
may then indicate that the system is now ready.
Regardless of whether your vehicle’s OBD system is
ready or not ready, if the MIL symbol is illuminated
during normal vehicle operation, you should have yourvehicle serviced before going to the I/M station. The I/M
station can fail your vehicle because the MIL symbol is on
with the engine running.
REPLACEMENT PARTS
Use of genuine Moparparts for normal/scheduled
maintenance and repairs is highly recommended to in-
sure the designed performance. Damage or failures
caused by the use of non-Moparparts for maintenance
and repairs will not be covered by the manufacturer’s
warranty.
DEALER SERVICE
Your dealer has the qualified service personnel, special
tools and equipment to perform all service operations in
an expert manner. Service Manuals are available which
include detailed service information for your vehicle.
Refer to these manuals before attempting any procedure
yourself.
252 MAINTAINING YOUR VEHICLE

NOTE:Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
WARNING!
You can be badly injured working on or around a
motor vehicle. Do only that service work for which
you have the knowledge and the proper equipment.
If you have any doubt about your ability to perform
a service job, take your vehicle to a competent
mechanic.
MAINTENANCE PROCEDURES
The pages that follow contain therequiredmaintenance
services determined by the engineers who designed your
vehicle.
Besides the maintenance items for which there are fixed
maintenance intervals, there are other items that should
operate satisfactorily without periodic maintenance.
However, if a malfunction of these items does occur, it
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 lubrication of your vehicle’s engine, the
engine oil must be maintained at the correct level. Check
the oil level at regular intervals, such as every fuel stop.
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•More than 50% of your driving is at sustained high
speeds during hot weather, above 90°F (32°C)
•Taxi, Police, or delivery service (commercial service)
•Trailer towing
•Off-road or desert driving
•If equipped for and operating with E–85 (ethanol) fuel
IfANYof these apply to you, then change your engine oil
at every interval shown in schedule “B” of the “Mainte-
nance Schedules” section of this manual.
If none of these apply to you, then change your engine oil
at every interval shown on schedule “A” of the “Main-
tenance Schedules” section of this manual
NOTE:Under no circumstances should oil change in-
tervals exceed 6,000 miles (10 000 km) or 6 months
whichever comes first.
Engine Oil Selection
For best performance and maximum protection for all
engines under all types of operating conditions, the
manufacturer recommends engine oils that are API Cer-
tified and meet the requirements of DaimlerChrysler
Material Standard MS-6395.
American Petroleum Institute (API) Engine Oil
Identification Symbol
This symbol means that the oil has
been certified by the American
Petroleum Institute (API). The
manufacturer only recommends
API Certified engine oils.
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Materials Added To Engine Oils
The manufacturerstrongly recommendsagainst the ad-
dition of any additives (other than leak detection dyes) to
engine oil. Engine oil is an engineered product and it’s
performance may be impaired by supplemental addi-
tives.
Disposing of Used Engine Oil
Care should be taken in disposing of used engine oil from
your vehicle. Used oil, indiscriminately discarded, can
present a problem to the environment. Contact your
authorized dealer, service station, or governmental
agency for advice on how and where used oil can be
safely discarded in your area.
Engine Oil Filter
The engine oil filter should be replaced at every engine
oil change.
Engine Oil Filter Selection
All of the manufacturer’s engines have a full-flow type
disposable oil filter. Use a filter of this type for replace-
ment. The quality of replacement filters varies consider-
ably. Only high quality filters should be used to assure
most efficient service. Moparengine oil filters are high
quality oil filters and are recommended.
Drive Belts — Check Condition and Tension
At the mileage shown in the appropriate “Maintenance
Schedule,” check all drive belts for condition and proper
tension. Improper belt tension can cause belt slippage
and failure.
Inspect the drive belt for evidence of cuts, cracks, or
glazing and replace them if there is any sign of damage
which could result in belt failure. If adjustment is re-
quired, adjust the belts according to the specifications
and procedures shown in the Service Manual.
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Special tools are required to properly measure tension
and to restore belt tension to factory specifications. Also,
check belt routing to make sure there is no interference
between the belts and other engine components.
Spark Plugs
Spark plugs must fire properly to assure engine perfor-
mance and emission control. New plugs should be in-
stalled at the mileage specified in the appropriate main-
tenance chart. The entire set should be replaced if there is
any malfunction due to a faulty spark plug.
Refer to the “Vehicle Emission Control Information” label
in the engine compartment for spark plug information.
Catalytic Converter
The catalytic converter requires the use of unleaded fuel
only. Leaded gasoline will destroy the effectiveness of the
converter 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
vehicle.
258 MAINTAINING YOUR VEHICLE

WARNING!
A hot exhaust system can start a fire if you park over
materials that can burn. Such materials might be
grass or leaves coming into contact with your ex-
haust system. Do not park or operate your vehicle in
areas where your exhaust system can contact any-
thing that can burn.
In unusual situations involving grossly malfunctioning
engine operation, a scorching odor may suggest severe
and abnormal catalyst overheating. If this occurs, stop
the vehicle, turn off the engine and allow it to cool.
Service, including a tune up to manufacturer’s specifica-
tions, should be obtained immediately.
To minimize the possibility of catalytic converter dam-
age:
•Do not shut off the engine or interrupt the ignition
when the transmission is in gear and the vehicle is in
motion.
•Do not try to start the engine by pushing or towing the
vehicle.
•Do not idle the engine with any spark plug wires
disconnected or removed, such as when diagnostic
testing.
•Do not idle the engine for prolonged periods during
very rough idle or malfunctioning operating condi-
tions.
•Do not allow vehicle to run out of fuel.
NOTE:Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
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To determine the battery charge, check the battery test
indicator (if equipped) on top of the battery. Refer to the
illustration.
CAUTION!
It is essential when replacing the cables on the
battery that the positive cable is attached to the
positive post and the negative cable is attached to the
negative post. Battery posts are marked (+) positive
and negative (-) and identified on the battery case.
Also, if a “fast charger” is used while battery is in the
vehicle, disconnect both vehicle battery cables be-
fore connecting the charger to battery. Do not use a
“fast charger” to provide starting voltage.
Air Conditioner Maintenance
For best possible performance, your air conditioner
should be checked and serviced by an Authorized Dealer
at the start of each warm season. This service should
include cleaning of the condenser fins and a performance
test. Drive belt tension should also be checked at this
time.
262 MAINTAINING YOUR VEHICLE

WARNING!
•Use only refrigerants and compressor lubricants
approved by the manufacturer for your air condi-
tioning system. Some unapproved refrigerants are
flammable and can explode, injuring you. Other
unapproved refrigerants or lubricants can cause
the system to fail, requiring costly repairs. Refer
to Section 3 of the Warranty Information Book for
additional warranty information.
•The air conditioning system contains refrigerant
under high pressure. To avoid risk of personal
injury or damage to the system, adding refrigerant
or any repair requiring lines to be disconnected
should be done by an experienced repairman.
Refrigerant Recovery and Recycling
R-134a Air Conditioning Refrigerant is a hydrofluorocar-
bon (HFC) that is endorsed by the Environmental Pro-
tection Agency and is an ozone-saving product. How-
ever, the manufacturer recommends that air conditioning
service be performed by dealers or other service facilities
using recovery and recycling equipment.
Power Steering Fluid Check
Checking the power steering fluid level at a defined
service interval is not required. The fluid should only be
checked if a leak is suspected, abnormal noises are
apparent, and/or the system is not functioning as antici-
pated. Coordinate inspection efforts through a certified
DaimlerChrysler Dealership.
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