2008 JEEP GRAND CHEROKEE fuel pressure

Seat belt assemblies must be replaced after an accident if
they have been damaged (bent retractor, torn webbing,
etc.). If there is any question regarding belt or retractor
condition, replace the belt.
Airbag Warning Light
The light should come on and remain on for 6 to 8
seconds as a bulb check when the ignition switch is first
turned on. If the bulb is not lit during starting, have it
replaced. If the light stays on or comes on while driving,
have the system checked by an authorized dealer.
Defrosters
Check operation by selecting the defrost mode and place
the blower control on high speed. You should be able to
feel the air directed against the windshield. See your
authorized dealer for service if your defroster is inoper-
able.
Safety Checks You Should Make Outside The
Vehicle
Tires
Examine tires for excessive tread wear or uneven wear
patterns. Check for stones, nails, glass, or other objects
lodged in the tread. Inspect for tread cuts or sidewall
cracks. Check wheel nuts for tightness and tires (includ-
ing spare) for proper pressure.
Lights
Have someone observe the operation of all exterior lights
while you work the controls. Check turn signal and high
beam indicator lights on the instrument panel.
Fluid Leaks
Check area under vehicle after overnight parking for fuel,
coolant, oil or other fluid leaks. Also, if gasoline fumes
are detected, the cause should be located and corrected
immediately.
70 THINGS TO KNOW BEFORE STARTING YOUR VEHICLE

12. Tire Pressure Monitoring Telltale Light
Each tire, including the spare (if provided),
should be checked monthly when cold and
inflated to the inflation pressure recommended
by the vehicle manufacturer on the vehicle
placard or tire inflation pressure label. (If your vehicle
has tires of a different size than the size indicated on the
vehicle placard or tire inflation pressure label, you should
determine the proper tire inflation pressure for those
tires.)
As an added safety feature, your vehicle has been
equipped with a tire pressure monitoring system (TPMS)
that illuminates a low tire pressure telltale when one or
more of your tires are significantly under-inflated. Ac-
cordingly, when the low tire pressure telltale illuminates,
you should stop and check your tires as soon as possible,
and inflate them to the proper pressure. Driving on a
significantly under-inflated tire causes the tire to over-
heat and can lead to tire failure. Under-inflation alsoreduces fuel efficiency and tire tread life, and may affect
the vehicle's handling and stopping ability.
Please note that the TPMS is not a substitute for proper
tire maintenance, and it is the driver 's responsibility to
maintain correct tire pressure, even if under-inflation has
not reached the level to trigger illumination of the TPMS
low tire pressure telltale.
Your vehicle has also been equipped with a TPMS
malfunction indicator to indicate when the system is not
operating properly. The TPMS malfunction indicator is
combined with the low tire pressure telltale. When the
system detects a malfunction, the telltale will flash for
approximately one minute and then remain continuously
illuminated. This sequence will continue upon subse-
quent vehicle start-ups as long as the malfunction exists.
When the malfunction indicator is illuminated, the sys-
tem may not be able to detect or signal low tire pressure
as intended. TPMS malfunctions may occur for a variety
UNDERSTANDING YOUR INSTRUMENT PANEL 191
4

²MEMORY #2 POSITIONS SET
²MEMORY SYSTEM DISABLED Ð SEATBELT BUCK-
LED (with graphic)
²MEMORY SYSTEM DISABLED Ð VEHICLE NOT IN
PARK
²DRIVER 1 MEMORY
²DRIVER 2 MEMORY
²ADJ. PEDALS DISABLED Ð CRUISE CONTROL SET
²ADJ. PEDALS DISABLED Ð SHIFTER IN REVERSE
²TIRE LOW PRESSURE
²CHECK TPM SYSTEM
²LEFT FRONT LOW PRESSURE (Premium TPM Sys-
tem Only)
²RIGHT FRONT LOW PRESSURE (Premium TPM Sys-
tem Only)
²LEFT REAR LOW PRESSURE (Premium TPM System
Only)
²RIGHT REAR LOW PRESSURE (Premium TPM Sys-
tem Only)
²SPARE LOW PRESSURE (Premium TPM System
Only)
²WATER IN FUEL (Diesel Models Only)
²SERVICE EXHAUST (Diesel Models Only)
200 UNDERSTANDING YOUR INSTRUMENT PANEL

located on the control panel. Conditioned air will be
directed through the outlets selected by the mode control.
A light in the snowflake button shows that the air
conditioning is on.
Slight changes in engine speed or power may be noticed
when the air conditioning compressor is on. This is a
normal occurrence as the compressor will cycle on and
off to maintain comfort and increase fuel economy.
Automatic Temperature Control Ð If Equipped
The Infrared Dual-Zone Climate Control System auto-
matically maintains the interior comfort level desired by
the driver and passenger. This is accomplished by a dual
sun-sensor in the top of the instrument panel, and an
infrared sensor located in the face of the control unit.
There are also various sensors monitored by this system
which take account for vehicle speed, A/C pressure,
outside temperature, and engine cooling temperature.
The infrared sensor independently measures the surfacetemperature of the driver and passenger. Based on the
sensor input, the system automatically adjusts the air
flow temperature, the air flow volume, and amount of
outside air recirculation. This maintains a comfortable
temperature even under changing conditions.
Automatic Temperature Controls
UNDERSTANDING YOUR INSTRUMENT PANEL 261
4

NTire Spinning........................321
NTread Wear Indicators..................322
NLife Of Tire.........................323
NReplacement Tires.....................323
NAlignment And Balance.................324
mTire Chains...........................325
mTire Rotation Recommendations............325
mTire Pressure Monitor System (TPMS)........326
NBase System Ð If Equipped..............329
NPremium System Ð If Equipped..........331
NGeneral Information...................336
mFuel Requirements......................336
N3.7/4.7L Engines (If Equipped)............336N5.7L Engines (If Equipped)...............337
NReformulated Gasoline.................337
NGasoline/Oxygenate Blends..............338
NMMT In Gasoline.....................338
NMaterials Added To Fuel................339
NFuel System Cautions..................339
NCarbon Monoxide Warnings..............340
mFlexible Fuel (4.7L Engine Only) Ð
If Equipped...........................340
NE-85 General Information................340
NEthanol Fuel (E-85)....................341
NFuel Requirements....................342
NSelection Of Engine Oil For Flexible Fuel
Vehicles (E-85) And Gasoline Vehicles.......343
STARTING AND OPERATING 273
5

After Starting
The idle speed is controlled automatically and it will
decrease as the engine warms up.
Normal Starting Ð Diesel Engines
Observe the following when the engine is operating.
²All message center lights are off.
²Malfunction Indicator Light (MIL) is off.
²Low Oil Pressure Light is off.
Cold Weather Precautions
Operation in ambient temperature below 32ÉF (0ÉC) may
require special considerations. The following chart sug-
gest these options:
*No. 1 Ultra Low Sulfur Diesel Fuel (ULSD) should only
be used where extended arctic conditions (-10ÉF/-23ÉC)
exist.
278 STARTING AND OPERATING

depending on engine temperature. When the ªGlow Plug
Indicator Lightº goes out, the engine is ready to start.
4. Tip Start Feature
Do notpress the accelerator. Use the Fob with Integrated
Key to briefly turn the ignition switch to the START
position and then release it. The starter motor will
continue to run, and it will automatically disengage
when the engine is running.
NOTE:The starter motor may run up to 30 seconds in
very cold conditions until the engine is started. The
starter can be disengaged by turning the ignition key to
the OFF position, if required.
5. After the engine starts, allow it to idle for approxi-
mately 30 seconds before driving. This allows oil to
circulate and lubricate the turbocharger.
Avoid prolonged idling in ambient temperatures below
0ÉF (-18ÉC). Long periods of idling may be harmful toyour engine because combustion chamber temperatures
can drop so low that the fuel may not burn completely.
Incomplete combustion allows carbon and varnish to
form on piston rings and injector nozzles. Also, the
unburned fuel can enter the crankcase, diluting the oil
and causing rapid wear to the engine.
Engine Warm-Up
Avoid full throttle operation when the engine is cold.
When starting a cold engine, bring the engine up to
operating speed slowly to allow the oil pressure to
stabilize as the engine warms up.
NOTE:High-speed, no-load running of a cold engine
can result in excessive white smoke and poor engine
performance. No-load engine speeds should be kept
under 1,200 rpm during the warm-up period, especially
in cold ambient temperature conditions.
280 STARTING AND OPERATING

2. EconomyÐ
Improper inflation pressures can cause uneven wear
patterns to develop across the tire tread. These abnormal
wear patterns will reduce tread life resulting in a need for
earlier tire replacement. Under inflation also increases
tire rolling resistance and results in higher fuel consump-
tion.
3. Ride Comfort and Vehicle StabilityÐ
Proper tire inflation contributes to a comfortable ride.
Over inflation produces a jarring and uncomfortable ride.
Both under inflation and over inflation affect the stability
of the vehicle and can produce a feeling of sluggish
response or over responsiveness in the steering.
Unequal tire pressures can cause erratic and unpredict-
able steering response.
Unequal tire pressure from side to side may cause the
vehicle to drift left or right.Tire Inflation Pressures
The proper cold tire inflation pressure is listed on either
the face of the driver's door or the driver's side ªBº pillar.
The pressure should be checked and adjusted as well as
inspecting for signs of tire wear or visible damage at least
once a month. Use a good quality pocket-type gauge to
Tire Placard Location
STARTING AND OPERATING 319
5