2005 JEEP GRAND CHEROKEE fuel pressure

12. Tire Pressure Monitor Warning Light
This light will turn on continuously when there
is a low tire pressure condition. The light will
also turn on if a problem exists with any tire
sensor. When a system fault is detected, the
indicator lamp will flash repetitively for ten seconds. The
flash cycle will repeat every ten minutes or until the fault
condition is removed and reset. The light will remain on
or flashing until the tire pressure is properly set or the
problem with the sensor is corrected.
This light will turn on momentarily as a bulb check when
the engine is started.
When the tire pressure monitoring system warning light
is lit, one or more of your tires is significantly underin-
flated. You should stop and check your tires as soon as
possible, and inflate them to the proper pressure as
indicated on the tire and loading information placard.
Driving on a significantly underinflated tire causes thetire to overheat and can lead to tire failure. Underinfla-
tion also reduces fuel efficiency and tire tread life, and
may affect the vehicle’s handling and stopping ability.
Each tire, including the spare, should be checked
monthly when cold and set to the recommended inflation
pressure as specified in the tire and loading information
placard. (See page 269 for more information.)
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.
The gauge pointer will likely indicate a higher tempera-
ture when driving in hot weather, up mountain grades,
or when towing a trailer. It should not be allowed to
exceed the upper limits of the normal operating range.
UNDERSTANDING YOUR INSTRUMENT PANEL 167
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▫Tire Pressure Monitoring — Premium System. . 271
▫General Information...................275

Tire Chains...........................275

Tire Rotation Recommendations............276

Fuel Requirements......................277
▫3.7/4.7L Engines (If Equipped)............277
▫5.7L Engines (If Equipped)...............277
▫Reformulated Gasoline.................278
▫Gasoline/Oxygenate Blends..............278
▫MMT In Gasoline.....................279
▫Materials Added To Fuel................279
▫Fuel System Cautions..................279
▫Carbon Monoxide Warnings..............280

Fuel Tank Filler Cap (Gas Cap).............281▫Loose Fuel Filler Cap Message............282

Trailer Towing.........................283
▫Trailer And Tongue Weight..............285
▫Trailer Tow Wiring....................286
▫Cooling System Tips—Trailer Towing.......287
▫Trailer Classifications...................288
▫Trailer Towing Capability................289

Recreational Towing (Behind Motorhome, Etc.) . . 290
▫Towing – 2WD Models.................290
▫Towing — Quadra-Trac I (Single-Speed
Transfer Case) 4WD Models..............290
▫Towing — Quadra–Trac II /Quadra–Drive II
4WD Models........................290

Snow Plow...........................293
STARTING AND OPERATING 229
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Torque Converter Clutch
A feature designed to improve fuel economy is included
in all automatic transmissions. A clutch within the torque
converter engages automatically at a calibrated speed at
light throttle. It engages at higher speeds under heavier
acceleration. This may result 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 Over-
drive and in Drive.
NOTE:The torque converter clutch will not engage
until the transmission fluid and engine coolant are warm
[usually after 1-3 miles (1.6 - 4.8 km) of driving]. Because
the engine speed is higher when the torque converter
clutch is not engaged, it may seem as if the transmission
is not shifting into Overdrive when cold. This is normal.
Manually shifting between 3 (third gear) and 4 (fourthgear) positions (using the ERS shift control) will demon-
strate that the transmission is able to shift into and out of
Overdrive.
NOTE:If the vehicle has not been driven in several
days, the first few seconds of operation after shifting the
transmission into gear may seem sluggish. This is due to
the fluid partially draining from the torque converter into
the transmission. This condition is normal and will not
cause damage to the transmission. The torque converter
will refill within five seconds of shifting from Park into
any other gear position.
Rocking the Vehicle
If the vehicle becomes stuck in snow, sand, or mud, it can
often be moved by a rocking motion. Move the gear
selector rhythmically between D (Drive) and R (Reverse),
while applying slight pressure to the accelerator.
238 STARTING AND OPERATING

2. Economy—
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 Stability—
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 “B” pillar.
The “Cold Inflation Pressure” of each tire should be
checked and adjusted at least once every month. Check
Tire Placard Location
264 STARTING AND OPERATING

Tread Wear Indicators
These indicators are narrow strips 1/16 inch (1.6 mm)
thick and are found in the tread pattern grooves.
When the tread pattern is worn down to these treadwear
indicators, the tires should be replaced.
Overloading your vehicle, long trips in very hot weather,
and driving on bad roads may result in greater wear.
Replacement Tires
The tires on your new vehicle provide a balance of many
characteristics. They should be inspected regularly for
wear and correct inflation pressure. The manufacturer
strongly recommends that you use tires equivalent to the
originals in quality and performance when replacement
is needed (see section on tread wear indicators). Failure
to use equivalent replacement tires may adversely affect
the safety, handling, ride and fuel economy of your
vehicle. We recommend that you contact your original
equipment tire dealer on any questions you may have on
tire specifications or capability.
STARTING AND OPERATING 267
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WARNING!
•Remove the fuel cap (gas cap) slowly to prevent
fuel spray from the filler neck which may cause
injury.
•The volatility of some gasoline may cause a
buildup of pressure in the fuel tank that may
increase while you drive. This pressure can result
in a spray of gasoline and/or vapors when the cap
is removed from a hot vehicle. Removing the cap
slowly allows the pressure to vent and prevents
fuel spray.
•Never have any smoking materials lit in or near
the vehicle when the fuel cap is removed or the
tank filled.
•Never add fuel to the vehicle when the engine is
running.
WARNING!
A fire may result if gasoline is pumped into a
portable container that is inside of a vehicle. You
could be burned. Always place gas containers on the
ground while filling.
TRAILER TOWING
In this section you will find information on limits to the
type of towing you can reasonably do with your vehicle.
And you will find safety tips. Before towing a trailer
carefully review this information to tow your load as
efficiently and safely as possible.
To maintain warranty coverage, follow the requirements
and recommendations in this manual concerning ve-
hicles used for trailer towing.
Perform maintenance services as prescribed in the appro-
priate “Maintenance Schedule.” Refer to Section 8 of this
STARTING AND OPERATING 283
5

The best time to check the engine oil level is about 5
minutes after a fully warmed engine is shut off or before
starting the engine after it has sat overnight.
Checking the oil while the vehicle is on level ground will
improve the accuracy of the oil level readings. Maintain
the oil level in the SAFE level range. Adding 1 U.S. Quart
(0.95L) of oil when the level is at the bottom of the SAFE
range will result in the level being at the top of the SAFE
range.
CAUTION!
Overfilling or underfilling the crankcase will cause
aeration or loss of oil pressure. This could damage
your engine.
Change Engine Oil
Road conditions as well as your kind of driving affect the
interval at which your oil should be changed. Check the
following to determine if any apply to you:
•Day or night temperatures are below 32°F (0°C)
•Stop and go driving
•Extensive engine idling
•Driving in dusty conditions
•Short trips of less than 10 miles (16.2 km)
•More than 50% of your driving is at sustained high
speeds during hot weather, above 90°F (32°C)
•Trailer towing
•Taxi, Police, or delivery service (Commercial Service)
•Off road or desert operation
•If equipped for and operating with E-85 (ethanol) fuel
MAINTAINING YOUR VEHICLE 317
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Auxiliary Electrical Outlet.................. 148
Auxiliary Power Outlet................... 148
Battery............................... 324
Emergency Starting..................... 303
Keyless Transmitter Replacement............ 21
Saving Feature (Protection)............... 112
Belts, Drive............................ 320
Belts, Seat.............................. 28
Body Mechanism Lubrication............... 327
B-Pillar Location........................ 259
Brake System........................... 334
Anti-Lock........................... 246
Hoses.............................. 335
Master Cylinder....................... 335
Parking............................. 244
Trailer Towing........................ 284
Warning Light........................ 164
Brake/Transmission Interlock............... 234Break-In Recommendations, New Vehicle........ 63
Bulb Replacement.....................350,351
Calibration, Compass..................... 182
Capacities, Fluid........................ 357
Caps, Filler
Fuel................................ 281
Radiator (Coolant Pressure)............... 331
Car Washes............................ 341
Carbon Monoxide Warning............64,140,280
Cargo Area Cover....................... 151
Cargo Area Features...................... 150
Cargo Compartment...................... 150
Light............................... 150
Luggage Carrier....................... 157
Cargo Light............................ 150
Cargo Load Floor........................ 154
Cargo Tie-Downs........................ 153
Carpeting............................. 343
INDEX 393
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