2008 JEEP WRANGLER check engine light

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.
380 MAINTAINING YOUR VEHICLE

CAUTION!
Be aware that if the fluid temperature is below 50° F
(10° C), it may not register on the dipstick. Do not add
fluid until the temperature is elevated enough to
produce an accurate reading.
7. Check for leaks. Release the parking brake.
NOTE: To prevent dirt and water from entering the
transmission after checking or replenishing fluid, make
certain that the dipstick cap is properly reseated. It is
normal for the dipstick cap to spring back slightly from
its fully seated positions, as long as its seal remains
engaged in the dipstick tube.
Special Additives
Automatic Transmission Fluid (ATF) is an engineered
product and its performance may be impaired by supple-
mental additives. Therefore, do not add any fluid addi-
tives to the transmission. The only exception to this
policy is the use of special dyes to aid in detecting fluid
leaks. In addition, avoid using transmission sealers as
they may adversely affect seals.
Hydraulic Clutch Fluid — Manual Transmission
The clutch hydraulic system is a sealed maintenance free
system. In the event of leakage or other malfunction, the
system must be replaced.
Manual Transmission
Selection of Lubricant
Use only manufacturer’s recommended manual trans-
mission fluid. Refer to Fluids, Lubricants, and Genuine
Parts in this section for the correct fluid type.
MAINTAINING YOUR VEHICLE 403
7

•Change your engine oil more often if you drive your
vehicle off-road for an extended period of time.
•Under no circumstances should oil change intervals
exceed 6,000 mi (10,000 km) or 6 months, whichever
comes first.
Your dealer will reset the oil change indicator message
after completing the scheduled oil change. If this sched-
uled oil change is performed by someone other than your
dealer the message can be reset by referring to the steps
described under “Odometer/Trip Odometer” in the “In-
strument Cluster Description” section of this manual.
At Each Stop for Fuel
•Check the engine oil level about 5 minutes after a fully
warmed engine is shut off. Checking the oil level while
the vehicle is on level ground will improve the accu-
racy of the oil level reading. Add oil only when the
level is at or below the ADD or MIN mark.
•Check the windshield washer solvent and add if
required.
Once a Month
•Check tire pressure and look for unusual wear or
damage.
•Inspect the battery and clean and tighten the terminals
as required.
•Check the fluid levels of coolant reservoir, brake
master cylinder, power steering and transmission and
add as needed.
•Check all lights and other electrical items for correct
operation.
MAINTENANCE SCHEDULES 429
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M A I
N T
E
N A
N CE
S
C
H E
D
U L
E
S

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

Engine Oil........................... 385
Finish Care ............................ 407
Flashers Hazard Warning ....................... 364
Turn Signal ..................... 207,421,422
Flooded Engine Starting ................... 273
Fluid Capacities ......................... 424
Fluid Level Checks ...................... 405
Automatic Transmission ................. 401
Engine Oil ........................... 383
Manual Transmission ................... 404
Power Steering ........................ 391
Fluids, Lubricants and Genuine Parts .......... 425
Fog Light Service ........................ 422
Fog Lights ........................... 99,422
Fold and Tumble Rear Seat .................. 89
Folding Rear Seat ........................ 92
Folding Windshield ...................... 191
Four Wheel Drive ....................... 285 Shifting
............................. 287
Four Wheel Drive Operation ................ 285
Four-Way Hazard Flasher .................. 364
Front Axle (Differential) ................... 405
Fuel ................................. 336
Filler Cap (Gas Cap) .................... 340
Filter ............................... 388
Gasoline ............................ 336
Gauge .............................. 206
Materials Added ....................... 338
Octane Rating ........................ 336
Requirements ......................... 424
Tank Capacity ........................ 424
Fuel System Caution ................... 338,341
Fuses ................................ 413
Gas Cap (Fuel Filler Cap) ...............340,380
Gasoline (Fuel) ......................... 336
Gasoline, Reformulated ................... 336
INDEX 451
10

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

Tires ............................... 317
Locking Axle ........................ 290,291
Locks Door .............................. 31,32
Power Door ........................... 33
Steering Wheel ......................... 14
Lower Anchors and Tether for CHildren
(LATCH) ............................ 68,69
Lubrication, Body ....................... 392
Maintenance Free Battery .................. 389
Maintenance Procedures ................... 383
Maintenance Schedule .................... 428
Malfunction Indicator Light (Check Engine) . . 213,380
Manual, Service ......................... 441
Manual Transmission .................. 275,403
Fluid Level Check ...................... 404
Lubricant Selection ..................... 403
Shift Speeds .......................... 276 Master Cylinder (Brakes)
.................. 400
Mini-Trip Computer ...................... 215
Mirrors ................................ 83
Outside .............................. 84
Rearview ............................. 83
Modifications/Alterations, Vehicle ............. 8
Modular Hard Top ....................... 125
Monitor, Tire Pressure System ............... 330
Mopar Parts ......................... 382,440
MP3 Player ............................ 250
Multi-Function Control Lever ................ 97
Navigation Radio ........................ 250
Navigation System ....................... 250
New Vehicle Break-In Period ................ 75
Occupant Restraints ....................... 40
Octane Rating, Gasoline (Fuel) .............. 336
Odometer ............................. 211
INDEX 455
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