check engine JEEP GRAND CHEROKEE 2008 WK / 3.G User Guide

of reasons, including the installation of replacement or
alternate tires or wheels on the vehicle that prevent the
TPMS from functioning properly. Always check the
TPMS malfunction telltale after replacing one or more
tires or wheels on your vehicle to ensure that the replace-
ment or alternate tires and wheels allow the TPMS to
continue to function properly.CAUTION!
The TPMS has been optimized for the original
equipment tires and wheels. TPMS pressures and
warning have been established for the tire size
equipped on your vehicle. Undesirable system opera-
tion or sensor damage may result when using re-
placement equipment that is not of the same size,
type, and/or style. After-market wheels can cause
sensor damage. Do not use aftermarket tire sealants
or balance beads if your vehicle is equipped with a
TPMS, as damage to the sensors may result.
13. Temperature Gauge
The temperature gauge shows engine coolant tempera-
ture. Any reading within the normal range indicates that
the engine cooling system is operating satisfactorily.
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16. Electronic Stability Program (ESP) Warning
Light/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 ªONº 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.
17. 4WD LOW Mode Indicator Light Ð If Equipped
This light alerts the driver that the vehicle is in
the 4WD LOW mode. The front and rear drive-
shafts are mechanically locked together forcing
the front and rear wheels to rotate at the same
speed.18. Seat Belt Reminder Light
When the ignition switch is first turned ON, this
light will turn on for 5 to 8 seconds as a bulb check.
During the bulb check, if the driver's seat belt is
unbuckled, a chime will sound. After the bulb check or
when driving, if the driver or front passenger seat belt
remains unbuckled, the Seat Belt Warning Light will flash
or remain on continuously. Refer to9Enhanced Driver
Seat Belt Reminder System (BeltAlert)9in the Occupant
Restraints section for more information.
19. Cruise Indicator Light
This indicator lights when the speed control
system is turned ON.
20. Odometer
The odometer shows the total distance the vehicle has
been driven.
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U.S. federal regulations require that upon transfer of
vehicle ownership, the seller certify to the purchaser the
correct mileage that the vehicle has been driven. There-
fore, if the odometer reading is changed during repair or
replacement, be sure to keep a record of the reading
before and after the service so that the correct mileage can
be determined.
21. Transmission Range Indicator
This display indicator shows the automatic transmission
gear selection.
22. Fuel Gauge
The pointer shows the level of fuel in the fuel tank when
the ignition switch is in the ON position.
23. Electronic Throttle Control (ETC) Warning Light
This light informs you of a problem with the
Electronic Throttle Control system. If a problem
is detected the light will come on while the
engine is running. Cycle the ignition key whenthe vehicle has completely stopped and the gear selector
is placed in the P (Park) position. The light should turn
off. If the light remains lit with the engine running your
vehicle will usually be drivable, however, see your dealer
for service as soon as possible. If the light is flashing
when the engine is running, immediate service is re-
quired and you may experience reduced performance, an
elevated/rough idle or engine stall and your vehicle may
require towing. The light will come on when the ignition
is first turned on and remain on briefly as a bulb check.
If the light does not come on during starting, have the
system checked by an authorized dealer.
24. Front Fog Light Indicator LightÐ If Equipped
This light shows the front fog lights are ON.
25. Voltage Warning Light
This light monitors the electrical system voltage.
The light should turn on momentarily as the
UNDERSTANDING YOUR INSTRUMENT PANEL 195
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Transmission Limp Home Mode
Transmission function is monitored for abnormal condi-
tions. If a condition is detected that could result in
transmission damage, the transmission limp home mode
will be engaged. In this mode, the transmission will
remain in the current gear (3.7L engine) or in direct gear
(4.7L and 5.7L engines) until the vehicle is brought to a
stop.
To reset the transmission, use the following procedure:
1. Stop the vehicle.
2. Move the shift lever to the P (Park) position.
3. Turn off the engine, be sure to turn the key to the
LOCK position.
4. Wait approximately 10 seconds, then restart the en-
gine.
5. Move the shift lever to the desired gear range.If the problem is no longer detected, the transmission will
return to normal operation. If the problem persists, P
(Park), R (Reverse), and N (Neutral) will continue to
operate. Only 2nd gear (3.7L engine) or 3rd gear (4.7L
and 5.7L engines) will be available in the D (Drive)
position. Have the transmission checked at your autho-
rized dealer as soon as possible.
Torque Converter Clutch
A feature, designed to improve fuel economy, has been
included in the automatic transmission on your vehicle.
A clutch within the torque converter engages automati-
cally at a calibrated speed at light throttle. It engages at
higher speeds under heavier acceleration. This may re-
sult in a slightly different feeling or response during
normal operation in high gear. When the vehicle speed
drops below a calibrated speed, or during acceleration,
the clutch automatically and smoothly disengages. The
feature is operational in Overdrive and in Drive.
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Shifting Procedures
4HIto4LOW
With the vehicle at speeds of 0 to 3 mph (0 to 5 km/h),
key ON or engine running, shift the transmission into N
(Neutral), and raise the transfer case T-handle. ªThe 4WD
LOW Indicator Lampº in the instrument cluster will
begin to flash and remain on solid when the shift is
complete. Release the T-handle.
NOTE:If shift conditions/interlocks are not met, or a
transfer case motor temperature protection condition
exists, a ªCHECK SHIFT PROCEDURESº message will
flash from the EVIC (Electronic Vehicle Information Cen-
ter). Refer to ªElectronic Vehicle Information Center
(EVIC)º in Section 4 of this manual.
Shifter T-Handle
296 STARTING AND OPERATING

4 LOW to 4 HI
With the vehicle at speeds of 0 to 3 mph (0 to 5 km/h),
key ON or engine running, shift the transmission into N
(Neutral), and raise the transfer case T-handle. The ª4WD
LOW Indicator Lampº in the instrument cluster will flash
and go out when the shift is complete. Release the
T-handle.
NOTE:If shift conditions/interlocks are not met, or a
transfer case motor temperature protection condition
exists, a ªCHECK SHIFT PROCEDURESº message will
flash from the EVIC (Electronic Vehicle Information Cen-
ter). Refer to ªElectronic Vehicle Information Center
(EVIC)º in Section 4 of this manual.NOTE:Shifting into or out of 4WD LOW is possible
with the vehicle completely stopped, however difficulty
may occur due to the mating clutch teeth not being
properly aligned. Several attempts may be required for
clutch teeth alignment and shift completion to occur. The
preferred method is with the vehicle rolling 0 to 3 mph (0
to 5 km/h). If the vehicle is moving faster than 3 mph (5
km/h), the transfer case will not allow the shift.
Neutral (N) Shift Procedure
1. Key ON, engine off.
2. Vehicle stopped, with foot on brake.
3. Place transmission in N (Neutral).
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Towing Tips Ð Automatic Transmission
The ªDº range can be selected when towing. However, if
frequent shifting occurs while in this range, the ºTow/
Haulº mode (if equipped) or a lower gear range should
be selected.
NOTE:Using the ºTow/Haulº mode (if equipped) or a
lower gear range while operating the vehicle under
heavy operating conditions will improve performance
and extend transmission life by reducing excessive shift-
ing 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 ªMain-
tenance Scheduleº in Section 8 of this manual for trans-
mission fluid change intervals.
NOTE:Check the automatic transmission fluid level
before towing.
Towing Tips Ð Electronic Speed Control (If
Equipped)
þ
Don't use in hilly terrain or with heavy loads.
þWhen 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.
þUse speed control in flat terrain and with light loads to
maximize fuel efficiency.
Towing Tips Ð Cooling System
To reduce potential for engine and transmission over-
heating, take the following actions:
þCity Driving
When stopped for short periods of time, put transmission
in N (Neutral) and increase engine idle speed.
þHighway Driving
Reduce speed.
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MAINTAINING YOUR VEHICLE
CONTENTS
mEngine Compartment ± 3.7L...............386
mEngine Compartment ± 4.7L...............387
mEngine Compartment ± 5.7L...............388
mEngine Compartment ± 3.0L Diesel..........389
mOnboard Diagnostic System Ð OBD II........390
NLoose Fuel Filler Cap Message............391
mEmissions Inspection And Maintenance
Programs............................391
mReplacement Parts......................393mDealer Service.........................393
mMaintenance Procedures..................394
NEngine Oil..........................394
NDrive Belts Ð Check Condition And Tension . . 398
NSpark Plugs.........................398
NSpark Plug Wires.....................398
NEngine Air Cleaner Filter................398
NCatalytic Converter....................399
NCrankcase Emission Control System........400
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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.4. As soon as you turn your key to the ON position, you
will see your MIL symbol come on as part of a normal
bulb check.
5. Approximately 15 seconds later, one of two things will
happen:
a. The MIL will flash for about 10 seconds and then
return to being fully illuminated until you turn off the
ignition key or start the engine. This means that your
vehicle's OBD system isnot readyand you shouldnot
proceed to the I/M station.
b. The MIL will not flash at all and will remain fully
illuminated until you turn off the ignition key or start
the engine. This means that your vehicle's OBD system
isreadyand you can proceed to the I/M station.
If your OBD system isnot ready,you should see your
authorized dealer or repair facility. If your vehicle was
recently serviced or had a battery failure or replacement,
392 MAINTAINING YOUR VEHICLE

you may need to do nothing more than drive your
vehicle as you normally would in order for your OBD
system to update. A recheck with the above test routine
may then indicate that the system is now ready.
Regardless of whether your vehicle's OBD system is
ready or not ready, if the MIL symbol is illuminated
during normal vehicle operation, you should have your
vehicle serviced before going to the I/M station. The I/M
station can fail your vehicle because the MIL symbol is on
with the engine running.
REPLACEMENT PARTS
Use of genuine Mopartparts for normal/scheduled
maintenance and repairs is highly recommended to in-
sure the designed performance. Damage or failures
caused by the use of non-Mopartparts for maintenance
and repairs will not be covered by the manufacturer's
warranty.
DEALER SERVICE
Your dealer has the qualified service personnel, special
tools and equipment to perform all service operations in
an expert manner. Service Manuals are available which
include detailed service information for your vehicle.
Refer to these manuals before attempting any procedure
yourself.
NOTE:Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
WARNING!
You can be badly injured working on or around a
motor vehicle. Do only that service work for which you
have the knowledge and the proper equipment. If you
have any doubt about your ability to perform a service
job, take your vehicle to a competent mechanic.
MAINTAINING YOUR VEHICLE 393
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