check engine light JEEP GRAND CHEROKEE 2007 WK / 3.G User Guide

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.
Loose Fuel Filler Cap Message
After fuel is added, the vehicle diagnostic system can
determine if the fuel filler cap is loose, improperly
installed, or damaged. A “CHECK GASCAP” message
will be displayed in the EVIC (Refer to Section 4 of this
358 MAINTAINING YOUR VEHICLE

manual). Tighten the gas cap until aclickingsound is
heard. This is an indication that the gas cap is properly
tightened.
This message may be temporarily overridden by pressing
either the C/T, STEP, or MENU buttons. However, after
one minute of no customer interaction, the EVIC will
display again the “CHECK GASCAP” message. The
message will remain displayed until the vehicle diagnos-
tic system can retest the fuel system. The test will
perform the next time the vehicle is started, if the vehicle
was keyed off above 40°F (4°C) outside temperature and
the following vehicle start is above 40°F (4°C) outside
temperature. It may be possible to have a message that
will not clear due to the test being disabled due to low
outside temperatures. If the test is performed and the
problem is gone, the message will disappear.
If the problem persists, the message will appear the next
time the vehicle is started. This might indicate a damagedcap. If the problem is detected twice in a row, the system
will turn on the Malfunction Indicator Light (MIL).
Resolving the problem will turn the MIL light off. See
your authorized dealer for service.
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
MAINTAINING YOUR VEHICLE 359
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Once a Month
•Check the 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 the coolant reservoir, brake
master cylinder, and transmission, and add as needed.
•Check all lights and all other electrical items for correct
operation.At Each Oil Change
•Change the engine oil filter.
•Inspect the exhaust system.
•Inspect brake hoses.
•Check the engine coolant/anti-freeze level, hoses, and
clamps.
•After completion of off-road operation, the underside
of the vehicle should be thoroughly inspected. Exam-
ine threaded fasteners for looseness.
414 MAINTENANCE SCHEDULES
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NOTE:Most vehicles are operated under the conditions
listed for Schedule “B.”
Second is Schedule“A”. It is for vehicles that are not
operated under any of the conditions listed under Sched-
ule “B.”
Use the schedule that best describes your driving condi-
tions. Where time and mileage are listed, follow the
interval that occurs first.
CAUTION!
Failure to perform the required maintenance items
may result in damage to the vehicle.
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 whilethe 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, add as required.
Once a Month
•Check the tire pressure and look for unusual wear or
damage.
•Inspect the battery, clean and tighten the terminals as
required.
•Check the fluid levels of engine coolant/anti-freeze
deaeration bottle, brake master cylinder, and transmis-
sion, and add as needed.
•Check all lights and all other electrical items for correct
operation.
434 SCHEDULE “A”
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ABS (Anti-Lock Brake System)............176,274
Adding Fuel........................... 313
Adding Washer Fluid..................... 165
Adjustable Pedals....................... 124
Air Cleaner, Engine (Engine Air Cleaner Filter) . . . 367
Air Conditioner Maintenance............... 371
Air Conditioning........................ 235
Air Conditioning, Operating Tips............ 242
Air Conditioning Refrigerant............... 372
Air Conditioning System.................. 235
AirFilter .............................. 367
Air Pressure, Tires....................... 288
Airbag................................ 43
Airbag Deployment....................... 50
Airbag Light....................... 52,66,176
Airbag Maintenance....................... 51
Alarm (Security Alarm)................. 18,177
Alarm System (Security Alarm)............... 18
Alignment and Balance................... 293Alterations/Modifications, Vehicle............. 9
Antenna, Satellite Radio................... 230
Antifreeze (Engine Coolant)................ 407
Anti-Lock Brake System (ABS)............129,274
Anti-Lock Warning Light.................. 176
Anti-Theft System..................... 18,177
Appearance Care........................ 389
Auto Down Power Windows................ 30
AutomaticDimmingMirror ................. 72
Automatic Door Locks..................... 27
Automatic Headlights..................... 114
Automatic Temperature Control (ATC)......... 236
Automatic Transmission................254,386
Adding Fluid......................... 387
Fluid and Filter Changes................. 386
Fluid Level Check...................... 386
FluidType ........................... 386
Special Additives...................... 388
Torque Converter...................... 260
452 INDEX

Filters
Air Cleaner.......................... 367
Engine Oil........................... 366
Engine Oil Disposal.................... 365
FinishCare ............................ 390
Flashers.............................. 338
Hazard Warning....................... 338
Turn Signal.....................175,403,404
Flexible Fuel Vehicles
Cruising Range........................ 311
Engine Oil........................... 311
Fuel Requirements..................309,310
Maintenance.......................... 312
Replacement Parts..................... 311
Starting............................. 311
Flipper Glass, Liftgate..................... 33
Flooded Engine Starting................... 249
Fluid Capacities......................... 407
Fluid Leaks............................. 66Fluid Level Checks
Automatic Transmission................. 386
Brake............................... 384
Engine Oil........................... 362
Power Steering........................ 372
Fluids, Lubricants and Genuine Parts.......... 408
Fog Light Service........................ 404
Fog Lights....................... 117,182,404
Folding Rear Seat........................ 104
Four Wheel Drive....................... 262
Operation........................... 262
Systems............................. 262
Four Wheel Drive Operation................ 262
Four-Way Hazard Flasher.................. 338
Freeing A Stuck Vehicle................... 261
FrontAxle(Differential) ................... 385
Fuel................................. 305
Filler Cap (Gas Cap).................... 313
Gasoline............................ 305
INDEX 457
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Headlight Switch...................... 114
Headlights........................... 402
Headlights On With Wipers............... 114
High Beam Indicator.................... 175
Illuminated Entry....................... 19
Instrument Cluster................... 114,116
Interior........................... 116,118
Lights On Reminder.................... 117
Low Fuel............................ 182
LowTire ............................ 178
Malfunction Indicator (Check Engine)........ 175
Map Reading......................... 119
Oil Pressure.......................... 177
Passing............................. 118
Reading.......................... 119,145
Rear Servicing........................ 404
Rear Tail............................ 404
Seat Belt Reminder..................... 181
Security Alarm (Theft Alarm).............. 177Service.............................. 402
Service Engine Soon (Malfunction Indicator) . . . 175
Side Marker.......................... 404
SmartBeams.......................... 115
Tire Pressure Monitoring (TPMS)........... 178
Tow/Haul Indicator.................... 180
Traction Control....................137,177
Turn Signal.................. 113,117,403,404
VanityMirror .......................... 76
Voltage............................. 182
Load Floor, Cargo....................... 163
Loading Vehicle......................... 316
Tires ............................... 283
Locks................................. 26
Automatic Door........................ 27
Child Protection........................ 28
Door................................ 26
Power Door........................... 26
INDEX 461
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Lower Anchors and Tether for CHildren
(LATCH)............................ 58,60
Lubrication, Body....................... 374
Luggage Rack (Roof Rack)................. 166
Lumbar Support........................ 101
Maintenance Free Battery.................. 370
Maintenance Procedures................... 362
Maintenance Schedule.................412,433
Diesel.............................. 433
Light Duty Schedule “A”................ 441
Light Duty Schedule “B”................. 436
Schedule “A”......................427,441
Schedule “B”......................415,436
Maintenance Schedules.................... 412
Malfunction Indicator Light (Check Engine) . . 175,359
Manual, Service......................... 448
Memory Feature (Memory Seat)............. 106
Memory Seat........................... 106Memory Seats and Radio.................. 106
Mini-Trip Computer...................... 193
Mirrors ................................ 72
Automatic Dimming..................... 72
Electric Powered....................... 75
Electric Remote........................ 75
Exterior Folding........................ 74
Heated.............................. 76
Outside.............................. 73
Rearview............................. 72
Vanity ............................... 76
Modifications/Alterations, Vehicle............. 9
Monitor, Tire Pressure System............... 295
Mopar Parts.........................361,447
Multi-Displacement Engine System........... 278
Multi-Function Control Lever............... 113
Navigation Radio........................ 220
Navigation System....................... 220
462 INDEX