2007 JEEP GRAND CHEROKEE cooling

CAUTION!
The TPMS has been optimized for the original
equipment tires and wheels. TPMS pressures and
warnings have been established for the tire size
equipped on your vehicle. Undesirable system op-
eration or sensor damage may result when using
replacement equipment that is not of the same size,
type, and/or style. After-market wheels can cause
sensor damage. Do not use tire sealant from a can, or
balance beads if your vehicle is equipped with a
TPMS, as damage to the sensors may result.
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.
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.
UNDERSTANDING YOUR INSTRUMENT PANEL 179
4

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.
15. TOW/HAUL Indicator Light — If Equipped
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. 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 “ON” 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 — 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.
180 UNDERSTANDING YOUR INSTRUMENT PANEL

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 — 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 surface
temperature 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.NOTE:The numbers on the temperature dial represent
a comfort setting when the Mode knob is set to Auto, and
not the actual air temperature.
Operation of the system is quite simple. Begin by turning
the right mode knob to AUTO, and place the blower
control (left knob) to either LO AUTO or HI AUTO. The
Automatic Temperature Controls
236 UNDERSTANDING YOUR INSTRUMENT PANEL

•Bi-Level
Air flows both through the outlets located in the
instrument panel and those located on the floor.
Air flows through the registers in the back of the
center console, and under the front seats to the rear
seat passengers. These registers can be closed to block
airflow. The center console outlets deliver conditioned
air while the floor outlets deliver heated air.
•Panel
Air flows through the outlets located in the in-
strument panel. Air flows through the registers in
the back of the center console to the rear seat passen-
gers. These registers can be closed to block airflow.
Depress this button to turn on and off the air
conditioning during manual operation only. Con-
ditioned outside air is then directed through theoutlets selected on the mode control dial. The button
includes an LED that illuminates when manual operation
is selected.
NOTE:To manually control the air conditioning the
mode selector must be moved out of the AUTO position.
This button can be used to block out smoke,
odors, dust, high humidity, or if rapid cooling
is desired. The recirculation mode should only
be used temporarily. The button includes an
LED that illuminates, which indicates that the recircula-
tion mode is active. You may use this feature separately.
UNDERSTANDING YOUR INSTRUMENT PANEL 241
4

When using the air conditioner in extremely heavy traffic
in hot weather especially when towing a trailer, addi-
tional engine cooling may be required. If this situation is
encountered, operate the transmission in a lower gear to
increase engine RPM, coolant flow and fan speed. When
stopped in heavy traffic, it may be necessary to shift into
N (Neutral) and depress the accelerator slightly for fast
idle operation to increase coolant flow and fan speed.
Your air conditioning system is also equipped with an
automatic recirculation system. When the system senses
a heavy load or high heat conditions, it may use partial
Recirculation A/C mode to provide additional comfort.Winter Operation
When operating the system during the winter months,
make sure the air intake, located directly in front of the
windshield, is free of ice, slush, snow, or other obstruc-
tions.
Vacation Storage
Anytime you store your vehicle, or keep it out of service
(i.e. vacation) for two weeks or more, run the air condi-
tioning system at idle for about five minutes in the fresh
air and high blower setting. This will insure adequate
system lubrication to minimize the possibility of com-
pressor damage when the system is started again.
UNDERSTANDING YOUR INSTRUMENT PANEL 243
4

of the desired top gear. For example, if the driver shifts
the transmission into 3 (third gear), the transmission will
never shift above third gear, but can shift down to 2
(second) or 1 (first), when needed.
On vehicles equipped with 4.7L or 5.7L engines, use of
ERS (or Tow/Haul mode) also enables a additional
underdrive gear which is not normally used during
through-gear accelerations. This additional grade im-
proves vehicle performance and cooling capability when
towing a trailer on certain grades. In ERS mode (on all
transmissions), 1st through 3rd gear are underdrive gears
and 4th gear is direct drive. ERS 5th gear (Overdrive) is
the same as the normal 4th gear.WARNING!
Do not downshift for additional engine braking on a
slippery surface. The drive wheels could lose their
grip and the vehicle could skid.
Screen Display12345*D
Actual Gear(s)
Allowed1 1-2 1-3 1-4 1-5 1-5
* Applies to vehicles equipped with 4.7L/5.7L engines
only.
NOTE:To select the proper gear position for maximum
deceleration (engine braking), move the shift lever to the
left “D(-)” and hold it there. The transmission will shift to
the range from which the vehicle can best be slowed
down.
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5

Towing Tips — Automatic Transmission
The “D” range can be selected when towing. However, if
frequent shifting occurs while in this range, the ”Tow/
Haul” mode (if equipped) or a lower gear range should
be selected.
NOTE:Using the ”Tow/Haul” mode (if equipped) or a
lower gear range while operating the vehicle under
heavy operating conditions will improve performance
and extend transmission life by reducing excessive shift-
ing and heat build up. This action will also provide better
engine braking.
The automatic transmission fluid and filter should be
changed if you REGULARLY tow a trailer for more than
45 minutes of continuous operation. Refer to “Mainte-
nance Schedule B” in Section 8 of this manual for
transmission fluid change intervals.
NOTE:Check the automatic transmission fluid level
before towing.
Towing Tips — Electronic Speed Control (If
Equipped)

Don’t use in hilly terrain or with heavy loads.
When using the speed control, if you experience speed
drops greater than 10 mph (16 km/h), disengage until
you can get back to cruising speed.
Use speed control in flat terrain and with light loads to
maximize fuel efficiency.
Towing Tips — Cooling System
To reduce potential for engine and transmission over-
heating, take the following actions:
City Driving
When stopped for short periods of time, put transmission
in neutral and increase engine idle speed.
Highway Driving
Reduce speed.
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5

Air Conditioning
Turn off temporarily.
Refer to Cooling System Operating information in the
Maintenance section of this manual for more informa-
tion.
RECREATIONAL TOWING (BEHIND
MOTORHOME, ETC.)
Towing – 2WD Models
Recreational towing is allowed ONLY if the driveshaft
is removed.Towing with the rear wheels on the ground
while the driveshaft is connected can result in severe
transmission damage.
Towing — Quadra-Trac I (Single-Speed Transfer
Case) 4WD Models
Recreational towing is not allowed.This model does not
have a N (Neutral) position in the transfer case.
Towing — Quadra–Trac II /Quadra–Drive II 4WD
Models
CAUTION!
Front or rear wheel lifts should not be used. Internal
damage to the transmission or transfer case will
occur if a front or rear wheel lift is used when
recreational towing.
NOTE:The transfer case must be in the N (Neutral)
position, and the transmission must be in the P (Park)
position for recreational towing.
332 STARTING AND OPERATING