check engine light JEEP GRAND CHEROKEE 2008 WK / 3.G Owners Manual

CAUTION!
An unlocked car is an invitation to thieves. Always
remove key from the ignition and lock all doors
when leaving the vehicle unattended.
Key-In-Ignition Reminder
If you open the driver's door and the key is in the
ignition, a chime will sound to remind you to remove the
key.
NOTE:The Key-In-Ignition reminder only sounds
when the ignition key is placed in the LOCK or ACC
position.
SENTRY KEY
The Sentry Key Immobilizer System prevents unautho-
rized vehicle operation by disabling the engine. The
system does not need to be armed or activated. Operation
is automatic, regardless of whether the vehicle is locked
or unlocked.
The system uses the factory-mated Fob with Integrated
Key and Wireless Ignition Node (WIN) to prevent unau-
thorized vehicle operation. Therefore, only Fobs that are
programmed to the vehicle can be used to start and
operate the vehicle. The system will shut the engine off in
two (2) seconds if someone uses an invalid Fob to start
the engine.
After turning the ignition switch to the ON position, the
Vehicle Security Alarm Indicator Light will turn on for
three (3) seconds for a bulb check. If the light remains on
after the bulb check, it indicates that there is a problem
with the electronics. In addition, if the light begins to
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flash after the bulb check, it indicates that someone used
an invalid Fob to start the engine. Either of these condi-
tions will result in the engine being shut off after two (2)
seconds.
If the Vehicle Security Alarm Indicator Light turns on
during normal vehicle operation (vehicle running for
longer than 10 seconds), it indicates that there is a fault in
the electronics. Should this occur, have the vehicle ser-
viced as soon as possible.
NOTE:
²The Sentry Key Immobilizer System is not compatible
with aftermarket remote starting systems. Use of these
systems may result in vehicle starting problems and
loss of security protection.
²Exxon/Mobil Speed Pass,Ÿ additional Fobs, or any
other transponder-equipped components on the same
key chain willnotcause a fault unless the additional
part isphysically held against the Fobbeing used tostart the vehicle. Cell phones, pagers, or other RF
electronics will not cause interference with this system.
All of the Fobs provided with your new vehicle have
been programmed to the vehicle electronics.
Replacement Keys
NOTE:Only Fobs that are programmed to the vehicle
electronics can be used to start and operate the vehicle.
Once a Fob is programmed to a vehicle, it cannot be
programmed to any other vehicle.
CAUTION!
Always remove Sentry Keys from the vehicle and
lock all doors when leaving the vehicle unattended.
At the time of purchase, the original owner is provided
with a four-digit PIN number. Keep the PIN in a secure
18 THINGS TO KNOW BEFORE STARTING YOUR VEHICLE

Maintaining Your Airbag System
WARNING!
²Modifications to any part of the airbag system could
cause it to fail when you need it. You could be
injured if the airbag system is not there to protect
you. Do not modify the components or wiring,
including adding any kind of badges or stickers to
the steering wheel hub trim cover or the upper right
side of the instrument panel. Do not modify the
front bumper or vehicle body structure.
²You need proper knee impact protection in a
collision. Do not mount or locate any aftermarket
equipment on or behind the knee bolsters.
²It is dangerous to try to repair any part of the
airbag system yourself. Be sure to tell anyone who
works on your vehicle that it has an airbag system.NOTE:
Perchlorate Material ± special handling may ap-
ply, See www.dtsc.ca.gov/hazardouswaste/perchlorate
Airbag Warning Light
You will want to have the airbag system ready to inflate
for your protection in an impact. The airbag system is
designed to be maintenance free. If any of the following
occurs, have an authorized dealer service the system
promptly:
²Does not come on during the 2.5 to 8 seconds after the
ignition switch is first turned on.
²Remains on after the 2.5 to 8 second interval.
²Flickers, or comes on and remains on for any period of
time while driving.
NOTE:If the speedometer, tachometer, or any engine
related gauges are not working, the airbag control mod-
ule may also be disabled. The airbags may not be ready
to inflate for your protection. Promptly check the fuse
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SAFETY TIPS
Exhaust Gas
WARNING!
Exhaust gases can injure or kill. They contain carbon
monoxide (CO) which is colorless and odorless.
Breathing it can make you unconscious and can
eventually poison you. To avoid breathing (CO)
follow the safety tips below.
²Do 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 a extended period. If the vehicle is
stopped in an open area with engine running for more
than a short period, adjust the ventilation system to
force fresh, outside air into the vehicle.
²Guard 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.
²Always 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 ve-
hicle. Otherwise poisonous gases could be drawn into
the vehicle.
Safety Checks You Should Make Inside The
Vehicle
Seat Belts
Inspect the belt system periodically, checking for cuts,
frays and loose parts. Damaged parts must be replaced
immediately. Do not disassemble or modify the system.
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INSTRUMENT CLUSTER DESCRIPTION
1. Speedometer
Indicates vehicle speed.
2. Brake Warning Light
The BRAKE warning light will come on when
the ignition is first turned on, and stay on
briefly as a bulb check. If the bulb does not
come on during starting, have the bulb re-
paired promptly. If the light stays on longer, it may be an
indication that the parking brake has not been released.
If the light remains on when the parking brake is off, it
indicates a possible brake hydraulic system malfunction
or low fluid level. In this case, the light will remain on
until the cause is corrected. If a brake malfunction is
indicated, immediate repair is necessary and continued
operation of the vehicle in this condition is dangerous.3. Turn Signal Indicator Light
The arrow will flash with the exterior turn signal
when the turn signal lever is operated.
If the vehicle electronics sense that the vehicle has
traveled about one mile with the turn signals on, a chime
will sound to alert you to turn the signals off. If either
indicator flashes at a rapid rate, check for a defective
outside light bulb.
4. High Beam Indicator Light
Indicates that headlights are on high beam.
5. Malfunction Indicator Light
This light is part of an onboard diagnostic system
called OBD II that monitors engine and auto-
matic transmission control systems. The light will
illuminate when the key is in the ON position
188 UNDERSTANDING YOUR INSTRUMENT PANEL

before engine start. If the bulb does not come on when
turning the key from OFF to ON, have the condition
checked promptly.
Certain conditions such as a loose or missing gas cap,
poor fuel quality, etc. may illuminate the light after
engine start. The vehicle should be serviced if the light
stays on through several of your typical driving cycles. In
most situations the vehicle will drive normally and will
not require towing.
The Malfunction Indicator Light flashes to alert you to
serious conditions that could lead to immediate loss of
power or severe catalytic converter damage. The vehicle
should be serviced as soon as possible if this occurs.
6. Airbag Warning Light
This light turns on and remains on for 6 to 8
seconds as a bulb check when the ignition
switch is first turned ON. If the light is not onduring starting, stays on, or turns on while driving, have
the system inspected by an authorized dealer as soon as
possible.
7. Anti-Lock Brake Warning Light
This light monitors the Anti-Lock Brake System.
The light will turn on when the ignition switch is
turned to the ON position and may stay on for as long as
four seconds.
If the ABS light remains on or turns on while driving, it
indicates that the Anti-Lock portion of the brake system
is not functioning and that service is required. However,
the conventional brake system will continue to operate
normally if the BRAKE warning light is not on.
If the ABS light is on, the brake system should be serviced
as soon as possible to restore the benefits of Anti-Lock
brakes. If the ABS light does not turn on when the
Ignition switch is turned to the ON position, have the
light inspected by an authorized dealer.
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8. Tachometer
The red segments indicate the maximum permissible
engine revolutions-per-minute (r.p.m. x 1000) for each
gear range. Before reaching the red area, ease up on the
accelerator.
9. Security Alarm System Indicator Light Ð If
Equipped
This light will flash rapidly for approximately 15 seconds
when the vehicle theft alarm is arming. The light will
flash at a slower speed continuously after the alarm is set.
The security light will also come on for about three
seconds when the ignition is first turned on.
10. Oil Pressure Warning Light
This light shows low engine oil pressure. The light
should turn on momentarily when the engine is
started. If the light turns on while driving, stop the
vehicle, and shut off the engine as soon as possible. A
continuous chime will sound when this light turns on.Do not operate the vehicle until the cause is corrected.
This light does not show how much oil is in the engine.
The engine oil level must be checked under the hood.
11. Electronic Stability Program (ESP) Indicator
Light/Traction Control System (TCS) Indicator Light
This indicator light starts to flash as soon as the
tires lose traction and the ESP system becomes
active. The ªESP/TCS Indicator Lightº also
flashes when TCS is active. If the ªESP/TCS
Indicator Lightº begins to flash during acceleration, ease
up on the accelerator and apply as little throttle as
possible. Be sure to adapt your speed and driving to the
prevailing road conditions. The ªESP/TCS Indicator
Lightº will flash any time the ESP or TCS is active and
helping to improve vehicle stability. If the ªESP/TCS
Indicator Lightº 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.
190 UNDERSTANDING YOUR INSTRUMENT PANEL

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.
194 UNDERSTANDING YOUR INSTRUMENT PANEL

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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