2006 JEEP GRAND CHEROKEE check engine light

CAUTION!
Damage to the fuel system or emission control
system could result from using an improper fuel cap
(gas cap). A poorly fitting cap could let impurities
into the fuel system. Also, a poorly fitting after-
market cap can cause the MIL (Malfunction Indica-
tor Light) to illuminate, due to fuel vapors escaping
from the system.
•Turn the engine off.
•Rotate the fuel cap to the left to remove.
•To replace the cap, insert it into the filler neck and
tighten the cap about 1/4 turn until you hear one click.
This is an indication that the cap is properly tightened.
•Make sure that the fuel cap tether strap is not caught
under the fuel cap.
CAUTION!
To avoid fuel spillage and overfilling, do not“top
off”the fuel tank after filling.
NOTE:When the fuel nozzle“clicks”or shuts off, the
fuel tank is full.
Loose Fuel Filler Cap Message
If the vehicle diagnostic system determines that the fuel
filler cap is loose, improperly installed, or damaged, a
“CHECK GAS CAP”message will be displayed in the
EVIC (Electronic Vehicle Information Center). Refer to
“Electronic Vehicle Information Center”in Section 4 of this
manual. Tighten the fuel filler cap properly and press the
odometer reset button to turn the message off. If the
problem continues, the message will appear the next time
the vehicle is started. Refer to“Onboard Diagnostic System
—OBDII”in Section 7 of this manual for more information.
STARTING AND OPERATING 307
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If using a manual transmission vehicle for trailer towing,
all starts must be in FIRST gear to avoid excessive clutch
slippage.
Towing Tips—Automatic Transmission
The“D”range can be selected when towing. However, if
frequent shifting occurs while in this range, the”Tow/
Haul”mode (if equipped) or the“3”range should be
selected. Shift the transmission to Drive position 2 on
more severe grades.
NOTE:Using the”Tow/Haul”mode (if equipped) or
the“3”range while operating the vehicle under heavy
operating conditions will improve performance and ex-
tend transmission life by reducing excessive 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. See Schedule“B”in
section 8 of this manual for transmission fluid change
intervals.
NOTE:Check the automatic transmission fluid level
before towing.
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.
STARTING AND OPERATING 319
5

cap until aclickingsound 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 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.
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.
348 MAINTAINING YOUR VEHICLE

•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 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.
398 MAINTENANCE SCHEDULES
8
M
A
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T
E
N
A
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C
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S
C
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E
D
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L
E
S

ABS (Anti-Lock Brake System)............181,269
Adding Washer Fluid..................... 171
Adjustable Pedals....................... 146
Air Cleaner, Engine (Engine Air Cleaner Filter) . . . 358
Air Conditioner Maintenance............... 359
Air Conditioning........................ 233
Air Conditioning, Operating Tips............ 237
Air Conditioning Refrigerant............... 360
Air Conditioning System.................. 233
Air Filter.............................. 358
Air Pressure, Tires....................... 288
Airbag................................ 41
Airbag Deployment....................... 53
Airbag Light.......................56,70,181
Airbag Maintenance....................... 55
Alarm (Security Alarm).................24,182
Alarm System (Security Alarm)............... 24
Alignment and Balance................... 293
Alterations/Modifications, Vehicle............. 8Antenna, Satellite Radio................... 230
Antifreeze (Engine Coolant)................ 392
Anti-Lock Brake System (ABS)............131,269
Anti-Lock Warning Light.................. 181
Anti-Theft System.....................24,182
Appearance Care........................ 376
Auto Down Power Windows................ 29
Automatic Dimming Mirror................. 79
Automatic Door Locks..................... 19
Automatic Headlights.................... 122
Automatic Temperature Control (ATC)......... 238
Automatic Transmission................254,371
Adding Fluid......................... 373
Fluid and Filter Changes................. 371
Fluid Level Check...................... 372
Fluid Type........................... 371
Special Additives...................... 374
Torque Converter...................... 260
Autostick............................. 256
424 INDEX

Fluid Capacities......................... 392
Fluid Leaks............................. 71
Fluid Level Checks
Automatic Transmission...............371,372
Engine Oil........................... 351
Power Steering........................ 360
Fluids, Lubricants and Genuine Parts.......... 393
Fog Light Service........................ 389
Fog Lights.......................125,186,389
Folding Rear Seat........................ 111
Four Wheel Drive....................... 262
Operation........................... 262
Systems............................. 262
Four Wheel Drive Operation................ 262
Four-Way Hazard Flasher.................. 328
Freeing A Stuck Vehicle................... 261
Front Axle (Differential)................... 375
Fuel................................. 302
Filler Cap (Gas Cap).................... 306Filler Door (Gas Cap)................... 306
Gasoline............................ 302
Gauge.............................. 186
Materials Added....................... 304
Octane Rating........................ 302
Requirements......................... 392
Tank Capacity........................ 392
Fuel System Caution...................304,307
Fuses................................ 380
Garage Door Opener (HomeLink) ........... 152
Gas Cap (Fuel Filler Cap)...............306,347
Gasoline (Fuel)......................... 302
Gasoline, Reformulated................... 303
Gasoline/Oxygenate Blends................ 303
Gauges
Coolant Temperature.................... 184
Fuel................................ 186
Speedometer......................... 180
INDEX 429
10

Cargo .............................. 165
Center Mounted Stop................... 391
Cruise.............................. 185
Daytime Running...................... 125
Dimmer Switch, Headlight.............121,126
Electronic Stability Program (ESP)
Indicator.......................140,182,185
Electronic Throttle Control Warning......... 186
Fog ..........................125,186,389
Four-Wheel Drive Indicator............... 185
Fuses............................... 380
Hazard Warning Flasher................. 328
Headlight Switch...................... 122
Headlights........................... 387
Headlights On With Wipers............... 123
High Beam Indicator.................... 180
Illuminated Entry....................... 16
Instrument Cluster..................122,124
Interior..........................120,124Lights On Reminder.................... 125
Low Fuel............................ 187
LowTire ............................ 183
Malfunction Indicator (Check Engine)........ 180
Map Reading......................... 120
Oil Pressure.......................... 182
Passing............................. 126
Reading..........................120,152
Rear Servicing........................ 390
Rear Tail............................ 390
Seat Belt Reminder..................... 185
Security Alarm (Theft Alarm).............. 182
Service.............................. 387
Service Engine Soon (Malfunction Indicator) . . . 180
Side Marker.......................... 390
SmartBeams.......................... 123
Tire Pressure Monitoring (TPMS)........... 183
Tow/Haul Indicator.................... 184
Traction Control....................140,182
432 INDEX

Turn Signal..................121,126,388,390
Vanity Mirror.......................... 82
Voltage............................. 187
Load Floor, Cargo....................... 169
Loading Vehicle
Tires ............................... 283
Locks................................. 16
Automatic Door........................ 19
Child Protection........................ 17
Door................................ 16
Liftgate, Tailgate........................ 16
Power Door........................... 19
Lower Anchors and Tether for CHildren
(LATCH)............................62,64
Lubrication, Body....................... 362
Luggage Rack (Roof Rack)................. 171
Lumbar Support........................ 108
Maintenance Free Battery.................. 358Maintenance Procedures................... 350
Maintenance Schedule.................... 396
Schedule“A”......................... 409
Schedule“B”......................... 399
Maintenance Schedules.................... 396
Malfunction Indicator Light (Check Engine) . . 180,348
Manual, Service......................... 420
Master Cylinder (Brakes).................. 370
Memory Feature (Memory Seat)............. 114
Memory Seat........................... 114
Memory Seats and Radio.................. 114
Mini-Trip Computer...................... 197
Mirrors................................ 78
Automatic Dimming..................... 79
Electric Powered....................... 81
Electric Remote........................ 81
Exterior Folding........................ 80
Heated.............................. 80
Outside.............................. 80
INDEX 433
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