check engine light JEEP WRANGLER UNLIMITED 2008 Owners Manual

•Do not inhale exhaust gases. They contain carbon
monoxide, a colorless and odorless gas which can kill.
Never run the engine in a closed area, such as a
garage, and never sit in a parked vehicle with the
engine running for an extended period. If the vehicle is
stopped in an open area with the engine running for
more than a short time, adjust the ventilation system
to force fresh, outside air into the vehicle.
•Guard against carbon monoxide with proper mainte-
nance. Have the exhaust system inspected every time
the vehicle is raised. Have any abnormal conditions
repaired promptly. Until repaired, drive with all side
windows fully open.
•Always run the climate control in panel or floor mode
when driving with any windows open, even if only
slightly, to help keep fresh air circulating inside the
vehicle. Otherwise poisonous gases could be drawn
into the vehicle.
•On hardtop models, keep the tailgate window closed
when driving your vehicle. On fabric top models, do
not drive with the rear window curtain up unless the
side curtains are also open. This will prevent carbon
monoxide and other poisonous exhaust gases from
entering the vehicle.
Safety Checks You Should Make Inside The
Vehicle
Seat Belts
Inspect the seat belt system periodically, checking for
cuts, frays and loose parts. Damaged parts must be
replaced immediately. Do not disassemble or modify the
system.
Seat belt assemblies must be replaced after an accident if
they have been damaged (bent retractor, torn webbing,
etc.). If there is any question regarding seat belt or
retractor condition, replace the seat belt.
76 THINGS TO KNOW BEFORE STARTING YOUR VEHICLE

If the rear wiper is operating when the ignition is turned
OFF, the wiper will automatically return to the “Park”
position. When the vehicle is restarted, the wiper will
resume function at whichever position the switch is set
at.
Adding Washer Fluid
The fluid reservoir for the windshield washers and the
rear window washer is shared. It is located in the front of
the engine compartment, and should be checked for fluid
level at regular intervals. Fill the reservoir with wind-
shield washer solvent (not radiator antifreeze) and oper-
ate the system for a few seconds to flush out the residual
water.
Rear Window Defroster — If Equipped
The pushbutton is located on
the bottom right side of the
blower control knob. Press
this button to turn on the rear
window defroster. An amber
light shows that the defroster
is on.

will flash anytime the ESP or TCS is active and helping to
improve vehicle stability. If the ESP/TCS Indicator Light
is on solid, the ESP system has been turned off by the
driver or a temporary condition exists that will not allow
full ESP function.
27. O/D (Overdrive) Off Indicator LightThis light will illuminate when the O/D OFF
button has been selected. The O/D OFF button is
located on the center console.
28. Sway Bar Indicator Light — If Equipped This light will illuminate when the front sway
bar is disconnected.
29. Electronic Stability Program (ESP)/Brake Assist
System (BAS) Warning Light The ESP/BAS Warning Light in the instrument
cluster comes on when the ignition switch is
turned to the ON position. The light should go out with the engine running. If the ESP/BAS Warning
Light comes on continuously with the engine running, a
malfunction has been detected in either the ESP or the
BAS system. If this light stays illuminated, have the ESP
and BAS checked at your authorized dealer as soon as
possible. Refer to “Electronic Brake Control System” in
Section 3 for more information.
30. Electronic Throttle Control (ETC) Warning Light —
If Equipped
This light informs you of a problem with the
Electronic Throttle Control System. If a prob-
lem is detected while the engine is running, the
light will either stay on or flash depending on
the nature of the problem. Cycle the ignition key when
the vehicle is safely and completely stopped and the shift
lever is placed in the PARK position. The light should
turn off. If the light remains on with the engine running,
your vehicle will usually be drivable, however, see your
authorized dealer for service as soon as possible.

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

Loose Fuel Filler Cap Message
After fuel is added, the vehicle diagnostic system can
determine if the fuel filler cap is possibly loose, improp-
erly installed, or damaged. A “gASCAP” message will be
displayed in the odometer. Tighten the gas cap until a
clickingsound 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 prob-
lem is detected twice in a row, the system will turn on the
“Malfunction Indicator Light.” Resolving the problem
will turn the “Malfunction Indicator Light.” off.
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 that require an Inspection and Mainte-
nance (I/M), this check verifies the Malfunction
Indicator Light (MIL) is functioning and is not on
when the engine is running, and that the OBD II system
is ready for testing.
Normally, the OBD II system will be ready. The OBD II
system may notbe ready if your vehicle was recently
serviced, recently had a dead battery, or a battery replace-
ment. If the OBD II system should be determined not
ready for the I/M test, your vehicle may fail the test.

ABS (Anti-Lock Brake System)............208,309
Adding Fuel ........................... 340
Adding Washer Fluid ..................... 198
Air Cleaner, Engine (Engine Air Cleaner Filter) . . . 389
Air Conditioner Maintenance ............... 390
Air Conditioning ..................... 261,264
Air Conditioning Controls ................. 264
Air Conditioning, Operating Tips ............ 265
Air Conditioning Refrigerant ............... 391
Air Conditioning System .................. 264
Air Filter .............................. 389
Air Pressure, Tires ....................... 322
Airbag ................................ 51
Airbag Deployment ....................... 57
Airbag Light ......................... 60,208
Airbag Maintenance ....................... 59
Airbag, Side ............................ 57
Alarm (Security Alarm) .................... 18
Alignment and Balance ................... 328 Alterations/Modifications, Vehicle
............. 8
Antenna, Satellite Radio ................... 255
Antifreeze (Engine Coolant) ................ 424
Anti-Lock Brake System (ABS) ............105,309
Anti-Lock Warning Light .................. 208
Appearance Care ........................ 406
Arming Theft System (Security Alarm) ......... 18
Audio Systems (Radio) .................... 250
Auto Down Power Windows ................ 37
Automatic Transmission ................... 401
Fluid and Filter Changes ................. 401
Fluid Level Check ...................... 401
Fluid Type ........................... 401
Gear Ranges .......................... 281
Shifting ............................. 281
Special Additives ...................... 403
Torque Converter ...................... 285
Auxiliary Electrical Outlet (Power Outlet) ....... 116
Auxiliary Power Outlet .................... 116
446 INDEX

Charging System Light.................... 206
Chart, Tire Sizing ........................ 314
Check Engine Light
(Malfunction Indicator Light) .............213,380
Child Restraint .................... 62,63,69,72
Child Restraint Tether Anchors .............68,69
Child Seat .............................. 67
Climate Control ......................... 259
Clock ........................... 224,236,251
Compact Disc (CD) Maintenance ............. 258
Compass .............................. 215
Compass Calibration ..................... 217
Computer, Trip/Travel .................... 215
Console ............................... 118
Console, Floor .......................... 118
Contract, Service ........................ 439
Converter, Catalytic ...................... 386
Cooling System ......................... 394
Adding Coolant (Antifreeze) .............. 396Coolant Capacity
...................... 424
Coolant Level ......................... 397
Disposal of Used Coolant ................ 397
Drain, Flush, and Refill .................. 395
Inspection ........................... 394
Points to Remember .................... 398
Pressure Cap ......................... 396
Selection of Coolant (Antifreeze) .........395,424
Temperature Gauge ..................... 209
Corrosion Protection ..................... 406
Crankcase Emission Control System .......... 388
Cruise Light ........................... 209
Cup Holder ............................ 117
Customer Assistance ..................... 437
Data Recorder, Event ...................... 60
Daytime Running Lights ................... 99
Dealer Service .......................... 382
Defroster, Rear Window ................... 198
448 INDEX

Back-Up............................. 422
Brake Assist Warning ................. 1 15,214
Brake Warning ........................ 207
Bulb Replacement ...................... 420
Cargo ............................... 95
Center Mounted Stop ................... 423
Check Engine (Malfunction Indicator) ........ 213
Cruise .............................. 209
Daytime Running ....................... 99
Dimmer Switch, Headlight ................ 98
Electronic Stability Program (ESP)
Indicator ....................... 1 15,213,214
Electronic Throttle Control Warning ......... 214
Engine Temperature Warning .............. 209
Fog .............................. 99,422
Hazard Warning Flasher ................. 364
Headlight Switch ....................... 97
Headlights ........................... 420
High Beam ........................... 207 High Beam Indicator
.................... 207
Instrument Cluster ...................... 97
Interior .............................. 95
Lights On Reminder ..................... 98
Low Fuel ............................ 206
LowTire ............................ 210
Oil Pressure .......................... 207
Passing .............................. 99
Rear Servicing ........................ 422
Rear Tail ............................ 422
Seat Belt Reminder ..................... 207
Sentry Key ........................... 209
Service .............................. 420
Side Marker .......................... 422
Tire Pressure Monitoring (TPMS) ........... 210
Traction Control ....................... 213
Turn Signal ................... 99,207,421,422
Warning (Instrument Cluster Description) ..... 206
Loading Vehicle ......................... 342
454 INDEX

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