2008 JEEP WRANGLER UNLIMITED spark plugs

Drive Belts — Check Condition and Tension
Belt tension is controlled by means of an automatic
tensioner. No belt tension adjustments are required.
However, belt and belt tensioner condition should be
inspected at the specified intervals, and replaced if re-
quired. See your authorized dealer for service
At the mileage indicated in the Maintenance Schedule,
the condition of all the belts and tensioner should be
checked. Refer to Section 8 of this manual. Improper belt
tension can cause belt slippage and failure.
Belts should be inspected for evidence of cuts, cracks,
glazing, or frayed cords and replaced if there is indication
of damage, which could result in belt failure. Low
generator belt tension can cause battery failure.
Also, check belt routing to make sure there is no inter-
ference 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 Maintenance Sched-
ule. Refer to Section 8 of this manual. The entire set
should be replaced if there is any malfunction due to a
faulty spark plug. Refer to Fluids, Lubricants, and Genu-
ine Parts in this section 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.
386 MAINTAINING YOUR VEHICLE

INTRODUCTION INTRODUCTION ROLLOVER WARNING HOW TO USE THIS MANUAL WARNINGS AND CAUTIONS VEHICLE IDENTIFICATION NUMBER VEHICLE MODIFICATIONS/ALTERATIONS THINGS TO KNOW BEFORE STARTING YOUR VEHICLE A WORD
ABOUT YOUR KEYS Ignition Key RemovalKey-In-Ignition ReminderSTEERING WHEEL LOCK To Manually Lock the Steering WheelTo Release the Steering Wheel LockSENTRY KEY Replacement KeysCustomer Key ProgrammingGeneral InformationSECURITY ALARM
SYSTEM - IF EQUIPPED To Set the AlarmTo Disarm the SystemILLUMINATED ENTRY REMOTE KEYLESS ENTRY - IF EQUIPPED To Unlock the Doors and Swing GateTo Lock the Doors and Swing GateUsing The Panic AlarmTo Turn Off Flash Lights With Lock
Programming Additional TransmittersGeneral InformationBattery ReplacementREMOTE STARTING SYSTEM - IF EQUIPPED DOORS Upper Half Door Window Removal (If Equipped)Upper Half Door Window Installation (If Equipped)Front Door RemovalRear Door Removal
(Four-Door Models)DOOR LOCKS Manual Door LocksPower Door Locks - If EquippedAutomatic Unlock Doors On ExitAutomatic Door LocksWINDOWS Power Windows - If EquippedRear Power Windows (Four-Door Models Only)Wind BuffetingREAR SWING GATE
OCCUPANT RESTRAINTS Lap/Shoulder BeltsRear Center Lap/Shoulder Belt Retractor Lock-Out (Four-Door Models Only)Adjustable Upper Shoulder Belt AnchorageSeat Belt PretensionersEnhanced Seat Belt Use Reminder System (BeltAlert)Seat Belts And Pregnant
WomenSeat Belt ExtenderDriver And Front Passenger Supplemental Restraint Systems (SRS) Child RestraintENGINE BREAK-IN RECOMMENDATIONS SAFETY TIPS Exhaust GasSafety Checks You Should Make Inside The VehicleSafety Checks You Should Make
Outside The VehicleUNDERSTANDING THE FEATURES OF YOUR VEHICLE MIRRORS Inside Day/Night MirrorOutside MirrorsHANDS-FREE COMMUNICATION (UConnect) SEATS Front Seat AdjustmentManual Seat Height Adjustment - If EquippedFront Seatback
ReclineFront Easy Entry Seats (Two-Door Models)Head RestraintsFold And Tumble Rear Seat (Two-Door Models)Removing the Rear Seat (Two-Door Models)Replacing the Rear Seat (Two-Door Models)60/40 Split Folding Rear Seat (Four-Door Models)To Raise the Rear
SeatTO OPEN AND CLOSE THE HOOD LIGHTS Interior LightsMultifunction Control LeverParking Lights, Instrument Panel Lights, and HeadlightsLights-On ReminderHeadlight Dimmer SwitchPassing LightFront Fog Lights - If EquippedTurn SignalsDaytime Running Lights
- If EquippedWINDSHIELD WIPERS AND WASHERS Intermittent Wiper SystemWindshield Wiper OperationWindshield WashersMist FeatureTILT STEERING COLUMN ELECTRONIC SPEED CONTROL - IF EQUIPPED To ActivateTo Set At A Desired SpeedTo Deactivate
To Resume SpeedTo Vary The Speed SettingManual TransmissionTo Accelerate For PassingELECTRONIC BRAKE CONTROL SYSTEM ABS (Anti-Lock Brake System)TCS (Traction Control System)BAS (Brake Assist System)ERM (Electronic Roll Mitigation)ESP (Electronic
Stability Program)ESP/BAS Warning LightELECTRICAL POWER OUTLET Electrical Outlet Use With Engine OffCUPHOLDERS Front CupholdersRear CupholdersSTORAGE Console Storage CompartmentRear Storage CompartmentDUAL TOP - IF EQUIPPED Removing
The Soft TopInstalling the Soft TopFREEDOM TOP THREE-PIECE MODULAR HARD TOP Front Panel(s) RemovalFront Panel(s) InstallationFront Panel(s) Installation Only (With Rear Hard Top Removed)Rear Hard Top RemovalRear Hard Top InstallationDOOR FRAME
Door Frame Removal (Two-Door Models)Door Frame Installation (Two-Door Models)Door Frame Removal (Four-Door Models)Door Frame Installation (Four-Door Models)SOFT TOP (TWO-DOOR MODELS) Folding Down The Soft Top Putting Up The Soft Top SUNRIDER
(TWO-DOOR MODELS) - IF EQUIPPED SUNRIDER (FOUR-DOOR MODELS) - IF EQUIPPED SOFT TOP (FOUR-DOOR MODELS) Folding Down The Soft Top Putting Up The Soft Top FOLDING WINDSHIELD Lowering The Windshield And Removing Side BarsRaising
The Windshield And Replacing Side BarsREAR WINDOW FEATURES - HARD TOP ONLY Rear Window Wiper/Washer - If EquippedRear Window Defroster - If EquippedUNDERSTANDING YOUR INSTRUMENT PANEL INSTRUMENT PANEL AND CONTROLS
INSTRUMENT CLUSTER INSTRUMENT CLUSTER DESCRIPTION COMPASS AND TRIP COMPUTER - IF EQUIPPED Control ButtonsTrip ConditionsCompass Temperature DisplayRADIO GENERAL INFORMATION Radio Broadcast SignalsTwo Types of SignalsElectrical
DisturbancesAM ReceptionFM ReceptionSALES CODE RES - AM/FM STEREO RADIO WITH CD PLAYER (MP3 AUX JACK) Operating Instructions - Radio ModeOperation Instructions - CD MODE for CD and MP3 Audio PlayNotes On Playing MP3 FilesLIST Button (CD
Mode for MP3 Play)INFO Button (CD Mode for MP3 Play)SALES CODE REQ - AM/FM STEREO RADIO AND 6-DISC CD/DVD CHANGER (MP3/WMA AUX JACK) Operating Instructions - Radio ModeOperation Instructions - (DISC MODE for CD and MP3/WMA Audio
Play, DVD-VIDEO)Notes On Playing MP3/WMA FilesLIST Button (DISC Mode for MP3/WMA Play)INFO Button (DISC Mode for MP3/WMA Play)SALES CODE RER - MULTIMEDIA SYSTEM - IF EQUIPPED Operating Instructions - Satellite RadioOperating Instructions -
Hands-Free Communication (UConnect) (If Equipped)Clock Setting ProcedureSATELLITE RADIO - IF EQUIPPED (REN/REQ/RER/RES RADIOS ONLY) System Act ivationElectronic Serial Number/Sirius Identification Number (ESN/SID)Selecting Satellite ModeSatellite
AntennaReception QualityOperating Instructions - Satellite ModeOperating Instructions - Hands-Free Phone (If Equipped)Operating Instruction s - Video Entertainment System (VES) (If Equipped)CD/DVD DISC MAINTENANCE RADIO OPERATION AND CELLULAR
PHONES CLIMATE CONTROLS Manual Heater OnlyManual Air Conditioning and Heating System - If EquippedAir ConditioningOperating TipsSTARTING AND OPERATING STARTING PROCEDURES Manual TransmissionAutomatic TransmissionNormal StartingExtreme
Cold Weather (below -20 degrees F or -29 degrees C)If Engine Fails to StartAfter StartingENGINE BLOCK HEATER - IF EQUIPPED MANUAL TRANSMISSION ShiftingDownshiftingReverse ShiftingAUTOMATIC TRANSMISSION Shift Lock Manual Override
Brake/Transmission Interlock SystemAutomatic Transmission with OverdriveFOUR-WHEEL DRIVE OPERATION (COMMAND-TRAC OR ROCK-TRAC) - IF EQUIPPED Operating Instructions/PrecautionsShift PositionsShifting ProcedureTRAC-LOK REAR AXLE - IF
EQUIPPED AXLE LOCK (TRU-LOK) - RUBICON MODELS REAR AXLE LOCK - 4WD NON-RUBICON MODELS (IF EQUIPPED) ELECTRONIC SWAY BAR DISCONNECT - IF EQUIPPED ON-ROAD DRIVING TIPS OFF-ROAD DRIVING TIPS Side Step Removal - If
EquippedThe Basics of Off-Road DrivingWhen To Use 4L (Low) RangeSimultaneous Brake And Throttle OperationDriving In Snow, Mud and SandCrossing Obstacles (Rocks And Other High Points)Hill ClimbingDriving Through WaterAfter Driving Off-RoadPARKING BRAKE
ANTI-LOCK BRAKE SYSTEM POWER STEERING TIRE SAFETY INFORMATION Tire Markings Tire Identification Number (TIN)Tire Loading and Tire PressureTIRES - GENERAL INFORMATION Tire PressureTire Inflation Pressures Tire Pressures for High-Speed Operation
Radial-Ply TiresTire SpinningTread Wear IndicatorsLife of TireReplacement TiresAlignment and BalanceTIRE CHAINS TIRE ROTATION RECOMMENDATIONS TIRE PRESSURE MONITOR SYSTEM (TPMS) Base SystemGeneral InformationFUEL REQUIREMENTS
Reformulated GasolineGasoline/Oxygenate BlendsMMT In GasolineMaterials Added To FuelFuel System CautionsCarbon Monoxide WarningsADDING FUEL Fuel Filler Cap (Gas Cap)VEHICLE LOADING Certification LabelTRAILER TOWING Common Towing Definitions
Trailer Hitch ClassificationTrailer Towing Weights (Maximum Trailer Weight Ratings)Trailer and Trailer Tongue WeightTowing RequirementsTowing TipsRECREATIONAL TOWING (BEHIND MOTORHOME, ETC.) Towing - 2WD ModelsTowing - 4WD ModelsWHAT TO DO
IN EMERGENCIES HAZARD WARNING FLASHERS IF YOUR ENGINE OVERHEATS JACKING AND TIRE CHANGING Jack LocationSpare Tire StowagePreparations For JackingJacking Instructions JUMP STARTING EMERGENCY TOW HOOKS - IF EQUIPPED TOWING
A DISABLED VEHICLE MAINTAINING YOUR VEHICLE ENGINE COMPARTMENT - 3.8L ONBOARD DIAGNOSTIC SYSTEM - OBD II Loose Fuel Filler Cap MessageEMISSIONS INSPECTION AND MAINTENANCE PROGRAMS REPLACEMENT PARTS AUTHORIZED
DEALER SERVICE MAINTENANCE PROCEDURES Engine OilDrive Belts - Check Condition and TensionSpark PlugsCatalytic ConverterCrankcase Emission Control SystemFuel FilterEngine Air Cleaner FilterMaintenance-Free BatteryAir Conditioner MaintenancePower
Steering Fluid CheckDriveline And Steering Component LubricationBody LubricationWindshield Wiper BladesWindshield And Rear Window WashersExhaust SystemCooling SystemHoses and Vacuum/Vapor HarnessesBrake SystemAutomatic TransmissionHydraulic Clutch
Fluid - Manual TransmissionManual TransmissionTransfer CaseFront/Rear Axle FluidMaintenance After Off-Road DrivingAppearance Care And Protection From CorrosionFUSES (TOTALLY INTEGRATED POWER MODULE) VEHICLE STORAGE REPLACEMENT BULBS
- IF EQUIPPED BULB REPLACEMENT Head LightFront Park/Turn SignalFront Side MarkerFront Fog LightRear Tail, Stop, Turn Signal, and Backup LightsCenter High-Mounted Stop Light (CHMSL)FLUID CAPACITIES FLUIDS, LUBRICANTS AND GENUINE PARTS Engine
ChassisMAINTENANCE SCHEDULES EMISSIONS CONTROL SYSTEM MAINTENANCE MAINTENANCE SCHEDULE Required Maintenance IntervalsIF YOU NEED CONSUMER ASSISTANCE SUGGESTIONS FOR OBTAINING SERVICE FOR YOUR VEHICLE Prepare
For The AppointmentPrepare A ListBe Reasonable With RequestsIF YOU NEED ASSISTANCE DaimlerChrysler Motors Corporation Customer CenterDaimlerChrysler Canada Inc. Customer CenterIn Mexico contactCustomer Assistance For The Hearing Or Speech Impaired
(TDD/TTY)Service ContractWARRANTY INFORMATION (U.S. Vehicles Only) MOPAR PARTS REPORTING SAFETY DEFECTS In The 50 United States And Washington, D.CIn CanadaPUBLICATION ORDER FORMS DEPARTMENT OF TRANSPORTATION UNIFORM
TIRE QUALITY GRADES TreadwearTraction GradesTemperature GradesINDEX