2008 JEEP GRAND CHEROKEE fuel pressure

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.
68 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 177
4

²LEFT REAR LOW PRESSURE (Premium TPM System
Only)
²RIGHT REAR LOW PRESSURE (Premium TPM Sys-
tem Only)
Trip Functions
Press and release the MENU button until one of the
following Trip Functions displays in the EVIC:
²Distance To Empty
²Trip A
²Trip B
²Elapsed Time
²Service Distance
²Engine Oil Pressure
²Engine Oil Temperature
²Display Units of Measure in
Press the SCROLL button to cycle through all the Trip
Computer functions.
The Trip Functions mode displays the following informa-
tion:
²Distance To Empty (DTE)
Shows the estimated distance that can be traveled with
the fuel remaining in the tank. This estimated distance is
determined by a weighted average of the instantaneous
and average fuel economy, according to the current fuel
tank level. DTE cannot be reset through the FUNCTION
SELECT button.
NOTE:Significant changes in driving style or vehicle
loading will greatly affect the actual drivable distance of
the vehicle, regardless of the DTE displayed value.
186 UNDERSTANDING YOUR INSTRUMENT PANEL

²When the DTE value is less than 30 miles (48 km)
estimated driving distance, the DTE display will
change to a text display of9LOW FUEL.9This display
will continue until the vehicle runs out of fuel. Adding
a significant amount of fuel to the vehicle will turn off
the9LOW FUEL9text and a new DTE value will
display.
²Trip A
Shows the total distance traveled for trip A since the last
reset.
²Trip B
Shows the total distance traveled for trip B since the last
reset.
²Elapsed Time
Shows the total elapsed time of travel since the last reset
when the ignition switch is in the ACC position. Elapsed
time will increment when the ignition switch is in the ON
or START position.
²Engine Oil Pressure
Shows the current engine oil pressure. The scale will read
from 0±100 psi (0±689 kPa).
²Engine Oil Temperature
Shows the current engine oil temperature. The scale will
read from 140É ± 300ÉF (60É ± 149ÉC).
²Display Units of Measure in:
To make your selection, press and release the FUNC-
TION SELECT button until ªUSº or ªMETRICº appears.
To Reset The Display
Reset will only occur while a resettable function is being
displayed. Press and release the FUNCTION SELECT
button once to clear the resettable function being dis-
played. To reset all resettable functions, press and release
the FUNCTION SELECT button a second time within 3
seconds of resetting the currently displayed function
(>Reset ALL will display during this 3 second window).
UNDERSTANDING YOUR INSTRUMENT PANEL 187
4

mTire Safety Information...................259
NTire Markings........................259
NTire Identification Number (TIN)..........262
NTire Loading And Tire Pressure...........263
mTires Ð General Information...............267
NRun Flat Tires........................267
NTire Pressure.........................267
NTire Inflation Pressures.................269
NTire Pressures For High Speed Operation....270
NRadial-Ply Tires......................271
NTire Spinning........................271
NTread Wear Indicators..................272
NLife Of Tire.........................272NReplacement Tires.....................273
NAlignment And Balance.................274
mTire Rotation Recommendations............275
mTire Pressure Monitor System (TPMS)........275
NPremium System......................275
NGeneral Information...................278
mFuel Requirements......................278
N6.1L Engine.........................278
NReformulated Gasoline.................279
NGasoline/Oxygenate Blends..............279
NMMT In Gasoline.....................280
NMaterials Added To Fuel................280
NFuel System Cautions..................280
240 STARTING AND OPERATING

1. SafetyÐ
WARNING!
Improperly inflated tires are dangerous and can cause
accidents.
²Under inflation increases tire flexing and can result in
tire failure.
²Over inflation reduces a tire's ability to cushion
shock. Objects on the road and chuck holes can cause
damage that results in tire failure.
²Unequal tire pressures can cause steering problems.
You could lose control of your vehicle.
²Overinflated or under inflated tires can affect vehicle
handling and can fail suddenly, resulting in loss of
vehicle control.
²Unequal tire pressures from one side of the vehicle to
the other can cause the vehicle to drift to the right or left.
Always drive with each tire properly inflated.
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.
268 STARTING AND OPERATING

any of the four active road tires. The vehicle may need to
be driven for up to 10 minutes above 15 mph (24 km/h)
in order for the TPMS to receive this information.
General Information
This device complies with part 15 of the FCC rules and
RSS 210 of Industry Canada. Operation is subject to the
following conditions:
²This device may not cause harmful interference.
²This device must accept any interference received,
including interference that may cause undesired op-
eration.
The tire pressure sensors are covered under one of the
following licenses:
United States.....................KR5S120123
Canada........................2671-S120123
FUEL REQUIREMENTS
6.1L Engine
The 6.1L engine is designed to meet all
emissions regulations and provide excel-
lent fuel economy and performance when
using high-quality premium unleaded
gasoline with an octane rating of 91 or
higher.
Light spark knock at low engine speeds is not harmful to
your engine. However, continued heavy spark knock at
high speeds can cause damage and immediate service is
required. Poor quality gasoline can cause problems such
as hard starting, stalling, and hesitations. If you experi-
ence these symptoms, try another brand of gasoline
before considering service for the vehicle.
278 STARTING AND OPERATING

WARNING!
²Overfilling the brake fluid reservoir can result in
spilling brake fluid on hot engine parts and the
brake fluid catching fire.
²Use of a brake fluid that has a lower initial boiling
point than the recommended MOPAR DOT 3
product or a brake fluid that is unidentified as to
FMVSS specification may result in sudden brake
failure during hard prolonged braking. You could
have an accident.
Use only brake fluid that has been in a tightly closed
container to avoid contamination from foreign matter or
moisture.
CAUTION!
Do not allow a petroleum base fluid to contaminate
the brake fluid, Seal damage may result.
Fuel System Hoses
Electronic Fuel Injection high pressure fuel systems are
designed with hoses and quick connect fittings which
have unique material characteristics to provide adequate
sealing and resist attack by deteriorated gasoline.
You are urged to use only the manufacturer's specified
hoses with quick connect fittings, or their equivalent in
material and specification, in any fuel system servicing. It
is mandatory to replace any damaged hoses or quick
connect fittings that have been removed during service.
Care should be taken in installing quick connect fittings
to insure they are properly installed and fully connected.
See your authorized dealer for service.
332 MAINTAINING YOUR VEHICLE