2005 JEEP GRAND CHEROKEE coolant temperature

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
4

CAUTION!
Driving with a hot engine cooling system could
damage your vehicle. If temperature gauge reads (H),
pull over and stop the vehicle. Idle the vehicle with
the air conditioner turned off until the pointer drops
back into the normal range. If the pointer remains on
the “H”, and you hear continuous chimes, turn the
engine off immediately, and call for service.
WARNING!
A hot engine cooling system is dangerous. You or
others could be badly burned by steam or boiling
coolant. If you decide to look under the hood your-
self, refer to Section 7 of this manual. Follow the
warnings under “Cooling System Pressure Cap.”
14. Electronic Vehicle Information Center Display
When the appropriate conditions exist, this display
shows the Electronic Vehicle Information Center (EVIC)
messages. Refer to “Electronic Vehicle Information Cen-
ter” later in this section. (See page 171 for more informa-
tion.)
15. TOW/HAUL Indicator Light
This light will illuminate when the TOW/
HAUL button has been selected. The TOW/
HAUL button is located in the center of the
instrument panel (below the climate controls).
16. 4WD LOW Mode Indicator Light — 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. (See page 239 for more information.)
168 UNDERSTANDING YOUR INSTRUMENT PANEL

After Starting
The idle speed will automatically decrease as the engine
warms up.
CAUTION!
Long periods of engine idling, especially at high
engine speeds can cause excessive exhaust tempera-
tures which can damage your vehicle. Do not leave
your vehicle unattended with the engine running.
ENGINE BLOCK HEATER — IF EQUIPPED
The engine block heater warms engine coolant and
permits quicker starts in cold weather. Connect the cord
to a standard 110-115 volt AC electrical outlet with
grounded, three wire extension cord.
Use the heater when temperatures below 0°F (-18°C) are
expected to last for several days.The engine block heater cord is located:
•3.7L/4.7L Engine — coiled and strapped to the engine
oil dipstick tube.
•5.7L Engine — bundled and fastened to the injector
harness.
WARNING!
Remember to disconnect the cord before driving.
Damage to the 110-115 volt AC electrical cord could
cause electrocution.
232 STARTING AND OPERATING

left “D(-)” and hold it there. The transmission will shift to
the range from which the vehicle can best be slowed
down.
Overdrive Operation
The overdrive automatic transmission contains an elec-
tronically controlled fourth and fifth speed (Overdrive).
The transmission will automatically shift from 3rd gear to
Overdrive if the following conditions are present:
•the transmission selector is in D (Drive);
•the engine coolant has reached normal operating tem-
perature;
•vehicle speed is above approximately 30 mph (48
km/h);
•the “TOW/HAUL” button has not been activated;
•transmission has reached normal operating tempera-
ture.NOTE:If the vehicle is started in extremely cold tem-
peratures, the transmission may not shift into Overdrive
and will automatically select the most desirable gear for
operation at this temperature. Normal operation will
resume when the transmission fluid temperature has
risen to a suitable level. Refer also to the Note under
torque converter clutch, later in this section.
If the transmission temperature gets extremely hot, the
transmission will automatically select the most desirable
gear for operation at this temperature. If the transmission
temperature becomes hot enough, the “TRANSMISSION
OVER TEMP” message may display and the transmis-
sion may downshift out of Overdrive until the transmis-
sion cools down. After cooldown, the transmission will
resume normal operation.
In high ambient temperatures with sustained high engine
speed and load, an upshift followed shortly thereafter by
236 STARTING AND OPERATING

have an authorized technician inspect the complete ex-
haust system and adjacent body areas for broken, dam-
aged, deteriorated, or mispositioned parts. Open seams
or loose connections could permit exhaust fumes to seep
into the passenger compartment. In addition, inspect the
exhaust system each time the vehicle is raised for lubri-
cation or oil change. Replace as required.
Cooling System
WARNING!
You or others can be badly burned by hot antifreeze/
coolant or steam from your radiator. If you see or
hear steam coming from under the hood, don’t open
the hood until the radiator has had time to cool.
Never try to open a cooling system pressure cap
when the radiator or coolant bottle is hot.
Engine Coolant Checks
Check antifreeze/coolant protection every 12 months
(before the onset of freezing weather, where applicable).
If antifreeze/coolant is dirty or rusty in appearance, the
system should be drained, flushed and refilled with fresh
antifreeze/coolant. Check the front of the A/C condenser
for any accumulation of bugs, leaves, etc. If dirty, clean by
gently spraying water from a garden hose vertically
down the face of the condenser.
Check the engine cooling system hoses for brittle rubber,
cracking, tears, cuts, and tightness of the connection at
the coolant recovery bottle and radiator. Inspect the
entire system for leaks.
With the engine at normal operating temperature (but
not running), check the cooling system pressure cap for
proper vacuum sealing by draining a small amount of
coolant from the radiator drain cock. If the cap is sealing
properly, the antifreeze/coolant will begin to drain from
MAINTAINING YOUR VEHICLE 329
7

Adding Engine Coolant
Your vehicle has been built with an improved antifreeze/
coolant that allows extended maintenance intervals. This
antifreeze/coolant can be used up to 5 Years or 100,000
miles before replacement. To prevent reducing this ex-
tended maintenance period, it is important that you use
the same antifreeze/coolant throughout the life of your
vehicle. Please review these recommendations for using
Hybrid Organic Additive Technology (HOAT)
antifreeze/coolant.
When adding antifreeze/coolant, a minimum solution of
50% recommended Mopar Antifreeze/ Coolant 5 Year/
100,000 Mile Formula HOAT (Hybrid Organic Additive
Technology), or equivalent, in water should be used. Use
higher concentrations (not to exceed 70%) if temperatures
below -34°F (-37°C) are anticipated.Use only high purity water such as distilled or deionized
water when mixing the water/antifreeze (coolant) solu-
tion. The use of lower quality water will reduce the
amount of corrosion protection in the engine cooling
system.
Please note that it is the owner’s responsibility to main-
tain the proper level of protection against freezing ac-
cording to the temperatures occurring in the area where
the vehicle is operated.
NOTE:Mixing antifreeze/coolant types will decrease
the life of the antifreeze/coolant and will require more
frequent antifreeze/coolant changes.
Cooling System Pressure Cap
The cap must be fully tightened to prevent loss of
antifreeze/coolant, and to insure that antifreeze/coolant
will return to the radiator from the coolant recovery tank.
MAINTAINING YOUR VEHICLE 331
7

The cap should be inspected and cleaned if there is any
accumulation of foreign material on the sealing surfaces.
WARNING!
The warning words DO NOT OPEN HOT on the
cooling system pressure cap are a safety precaution.
Never add antifreeze/coolant when the engine is
overheated. Do not loosen or remove the cap to cool
an overheated engine. Heat causes pressure to build
up in the cooling system. To prevent scalding or
injury, do not remove the pressure cap while the
system is hot or under pressure.
Disposal of Used Engine Coolant
Used ethylene glycol-based antifreeze/coolant is a regu-
lated substance requiring proper disposal. Check with
your local authorities to determine the disposal rules for
your community. To prevent ingestion by animals andchildren, do not store ethylene glycol-based antifreeze/
coolant in open containers or allow it to remain in
puddles on the ground. If ingested by a child, contact a
physician immediately. Clean up any ground spills im-
mediately.
Engine Coolant Level
The coolant bottle provides a quick visual method for
determining that the antifreeze/coolant level is adequate.
With the engine idling, and warm to normal operating
temperature, the level of the antifreeze/coolant in the
bottle should be between the ranges indicated on the
bottle.
The radiator normally remains completely full, so there is
not need to remove the radiator cap unless checking for
antifreeze/coolant freeze point or replacing antifreeze/
coolant. Advise your service attendant of this. As long as
the engine operating temperature is satisfactory, the
coolant bottle need only be checked once a month.
332 MAINTAINING YOUR VEHICLE

Schedule “B”
Follow this schedule if you usually operate your vehicle
under one or more of the following conditions.
•Day or night temperatures are below 32°F (0°C)
•Stop and go driving
•Excessive 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 driving
•If equipped for and operated with E-85 (ethanol)
fuel.
NOTE:IfANYof these apply to you, change your
engine oil every 3,000 miles (5 000 km) or 3 months,
whichever comes first, and follow the maintenance rec-
ommendations in “Maintenance Schedule B.”
NOTE:IfANYof these apply to you then flush and
replace your engine coolant every 102,000 miles (163 000
km) or 60 months, whichever comes first, and follow
“Schedule B” of the “Maintenance Schedules” section of
this manual.
SCHEDULE “B” 365
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