2012 JEEP GRAND CHEROKEE heating

Electronic Range Select (ERS) Operation
The Electronic Range Select (ERS) shift control
allows the driver to limit the highest available
gear when the shift lever is in the DRIVE
position. For example, if you shift the transmis-
sion into 3 (third gear), the transmission will
never shift above third gear, but will shift down
into second and first gear normally.
Use of ERS (or TOW/HAUL mode) also enables
an additional underdrive gear which is not
normally used during through-gear accelera-
tions. This additional gear can improve vehicle
performance and cooling capability when tow-
ing a trailer on certain grades. In ERS mode,
gears 1 though 3 are underdrive gears, and
ERS 4 is direct drive. ERS 5 and 6 (Overdrive
gears ) are the same as the normal fourth and
fifth gears.
You can switch between DRIVE and ERS mode
at any vehicle speed. When the shift lever is in
the DRIVE position, the transmission will oper-
ate automatically, shifting between all available
gears. Tapping the shift lever to the left (-) will
activate ERS mode, display the current gear in
the instrument cluster, and maintain that gear
as the top available gear. Once in ERS mode,tapping the shift lever to the left (-) or right (+)
will change the top available gear.
To exit ERS mode, simply press and hold the
shift lever to the right (+) until “D” is once again
displayed in the shift lever position indicator in
the instrument cluster.
WARNING!
Do not downshift for additional engine braking
on a slippery surface. The drive wheels could
lose their grip and the vehicle could skid,
causing an accident or personal injury.
Screen
Display
123456D
Actual
Gear(s)
Allowed 1 1-2 1-3 1,2,4 1,2,
4,51,2,
4-6 1-5
NOTE:
To select the proper gear position for maxi-
mum deceleration (engine braking), simply
press and hold the shift lever to the left (-).
The transmission will shift to the range from
which the vehicle can best be slowed down. Overdrive Operation
The automatic transmission includes an elec-
tronically controlled Overdrive (fourth and fifth
gears). The transmission will automatically shift
into the Overdrive gear if the following condi-
tions are present:
•
the shift lever is in the DRIVE position,
• the transmission fluid has reached an ad-
equate temperature,
• the engine coolant has reached an adequate
temperature,
• vehicle speed is sufficiently high,
• the driver is not heavily pressing the accel-
erator, and
• the TOW/HAUL switch has not been acti-
vated.
When To Use TOW/HAUL Mode
When driving in hilly areas, towing a trailer,
carrying a heavy load, etc., and frequent trans-
mission shifting occurs, press the TOW/HAUL
switch to select TOW/HAUL mode. This will
improve performance and reduce the potential
for transmission overheating or failure due to
230

NOTE:
Your vehicle is capable of water fording in
up to 20 inches (51 cm) of water, while
crossing small rivers or streams. To main-
tain optimal performance of your vehicle’s
heating and ventilation system it is recom-
mended to switch the system into recircula-
tion mode during water fording.
CAUTION!
When driving through water, do not exceed
5 mph (8 km/h). Always check water depth
before entering, as a precaution, and check all
fluids afterward. Driving through water may
cause damage that may not be covered by the
New Vehicle Limited Warranty.
Driving through water more than a few inches/
centimeters deep will require extra caution to
ensure safety and prevent damage to your
vehicle. If you must drive through water, try to
determine the depth and the bottom condition
(and location of any obstacles) prior to enter-
ing. Proceed with caution and maintain a steady controlled speed less than 5 mph
(8 km/h) in deep water to minimize wave ef-
fects.
Flowing Water
If the water is swift flowing and rising (as in
storm run-off), avoid crossing until the water
level recedes and/or the flow rate is reduced. If
you must cross flowing water avoid depths in
excess of 9 inches (23 cm). The flowing water
can erode the streambed, causing your vehicle
to sink into deeper water. Determine exit
point(s) that are downstream of your entry point
to allow for drifting.
Standing Water
Avoid driving in standing water deeper than
20 inches (51 cm), and reduce speed appro-
priately to minimize wave effects. Maximum
speed in 20 inches (51 cm) of water is less than
5 mph (8 km/h).
Maintenance
After driving through deep water, inspect your
vehicle fluids and lubricants (engine oil, trans-
mission oil, axle, transfer case) to assure the
fluids have not been contaminated. Contami-
nated fluid (milky, foamy in appearance) shouldbe flushed/changed as soon as possible to
prevent component damage.
Driving In Snow, Mud And SandIn heavy snow, when pulling a load, or for
additional control at slower speeds, shift the
transmission to a low gear and shift the transfer
case to 4WD LOW if necessary. Refer to “Four-
Wheel Drive Operation” in “Starting and Oper-
ating” for further information. Do not shift to a
lower gear than necessary to maintain forward
motion. Over-revving the engine can spin the
wheels and traction will be lost.
Avoid abrupt downshifts on icy or slippery
roads, because engine braking may cause
skidding and loss of control.
Hill Climbing
NOTE:
Before attempting to climb a hill, determine
the conditions at the crest and/or on the
other side.
Before climbing a steep hill,
shift the trans-
mission to a lower gear and shift the transfer
case to 4WD LOW. Use first gear and 4WD
LOW for very steep hills.
240

Towing TipsBefore setting out on a trip, practice turning,
stopping and backing the trailer in an area
away from heavy traffic.
Automatic Transmission
The DRIVE range can be selected when tow-
ing. 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 TOW/HAUL mode (if equipped) or se-
lecting a lower gear range (using the Elec-tronic Range Select (ERS) shift control)
while operating the vehicle under heavy op-
erating conditions, will improve perfor-
mance and extend transmission life by re-
ducing excessive shifting and heat buildup.
This action will also provide better engine
braking.
The transmission fluid and filter should be
changed if you REGULARLY tow a trailer for
more than 45 minutes of continuous operation.
Refer to “Maintenance Schedule” for the proper
maintenance intervals.
NOTE:
Check the transmission fluid level before
towing (5.7L engine).
To avoid transmission overheating, when
towing a loaded trailer up steep grades at
low speeds (20 mph (32 km/h) or below),
holding your vehicle in first gear (using the
ERS shift control) is recommended (5.7L
Models Only).
274

Electronic Speed Control – If Equipped
Do not use in hilly terrain or with heavy loads.
When using the speed control, if you expe-rience 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.
Cooling System
To reduce potential for engine and transmission
overheating, take the following actions:
City Driving
When stopped for short periods of time, shift
the transmission into NEUTRAL and increase
engine idle speed.
Highway Driving
Reduce speed.
Air Conditioning
Turn off temporarily. Trailer Hitch Attaching Points
Your vehicle will require extra equipment to tow
a trailer safely and efficiently. The trailer tow
hitch must be attached to your vehicle using
the provided attaching points on the vehicle’s
frame. Refer to the following chart to determine
the accurate attaching points. Other equip-
ment, such as trailer sway controls and braking
equipment, trailer equalizing (leveling) equip-
ment and low profile mirrors, may also be
required or strongly recommended.Trailer Tow Hitch Attaching Points And
Overhang Dimensions
Fixed, Detach andRetractable Hitch
A 1.85 ft. (565 mm)
B 2.09 ft. (636 mm)
C 2.32 ft. (707 mm)
D 2.4 ft. (733 mm)
E 1.62 ft. (494 mm)
F 1.47 ft. (447 mm)
275

HAZARD WARNING FLASHERSThe Hazard Warning flasher switch is located
on the switch bank just above the climate
controls.Press the switch to turn on the Hazard
Warning flasher. When the switch is
activated, all directional turn signals will
flash on and off to warn oncoming
traffic of an emergency. Press the switch a
second time to turn off the Hazard Warning
flashers.
This is an emergency warning system and it
should not be used when the vehicle is in
motion. Use it when your vehicle is disabled
and it is creating a safety hazard for other
motorists.
When you must leave the vehicle to seek assis-
tance, the Hazard Warning flashers will con-
tinue to operate even though the ignition is
placed in the OFF position.
NOTE:
With extended use the Hazard Warning
flashers may wear down your battery.IF YOUR ENGINE OVERHEATSIn any of the following situations, you can
reduce the potential for overheating by taking
the appropriate action.
• On the highways — slow down.
• In city traffic — while stopped, place the
transmission in NEUTRAL, but do not in-
crease the engine idle speed.
NOTE:
There are steps that you can take to slow
down an impending overheat condition:
• If your air conditioner (A/C) is on, turn it
off. The A/C system adds heat to the
engine cooling system and turning the
A/C off can help remove this heat.
• You can also turn the temperature control
to maximum heat, the mode control to
floor and the blower control to high. This
allows the heater core to act as a supple-
ment to the radiator and aids in removing
heat from the engine cooling system.CAUTION!
Driving with a hot cooling system could dam-
age your vehicle. If the temperature gauge
reads HOT (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 HOT (H), and
you hear continuous chimes, turn the engine
off immediately and call for service.
WARNING!
You or others can be badly burned by hot
engine coolant (antifreeze) or steam from
your radiator. If you see or hear steam coming
from under the hood, do not 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.
282

CAUTION!
Racing the engine or spinning the wheels may
lead to transmission overheating and failure.
Allow the engine to idle with the shift lever in
NEUTRAL for at least one minute after every
five rocking-motion cycles. This will minimize
overheating and reduce the risk of transmis-
sion failure during prolonged efforts to free a
stuck vehicle.
CAUTION!
•When “rocking” a stuck vehicle by moving
between DRIVE and REVERSE, do not
spin the wheels faster than 15 mph
(24 km/h), or drivetrain damage may result.
• Revving the engine or spinning the wheels
too fast may lead to transmission overheat-
ing and failure. It can also damage the tires.
Do not spin the wheels above 30 mph
(48 km/h) while in gear (no transmission
shifting occurring).
WARNING!
Fast spinning tires can be dangerous. Forces
generated by excessive wheel speeds may
cause damage, or even failure, of the axle and
tires. A tire could explode and injure someone.
Do not spin your vehicle’s wheels faster than
30 mph (48 km/h) or for longer than 30 sec-
onds continuously without stopping when you
are stuck and do not let anyone near a
spinning wheel, no matter what the speed.
TOW EYESYour vehicle is equipped with tow eyes, which
are mounted in the front and the rear.
CAUTION!
Tow eyes are for emergency use only, to
rescue a vehicle stranded off road. Do not use
tow eyes for tow truck hookup or highway
towing. You could damage your vehicle. Tow
straps are recommended when towing the
vehicle; chains may cause vehicle damage.
WARNING!
Stand clear of vehicles when pulling with tow
eyes. Tow straps and chains may break, caus-
ing serious injury.
SHIFT LEVER OVERRIDEIf a malfunction occurs and the shift lever
cannot be moved out of the PARK position, you
can use the following procedure to temporarily
move the shift lever:
1. Firmly apply the parking brake.
2. Turn the engine OFF.
3. Remove the rubber liner from the cupholder
(located next to the shifter on the center con-
sole).
4. Using a screwdriver or similar tool, carefully
remove the shift lever override access cover,
located on the bottom of the cupholder.
290

CAUTION!
Damage to the catalytic converter can result if
your vehicle is not kept in proper operating
condition. In the event of engine malfunction,
particularly involving engine misfire or other
apparent loss of performance, have your ve-
hicle serviced promptly. Continued operation
of your vehicle with a severe malfunction
could cause the converter to overheat, result-
ing in possible damage to the converter and
vehicle.
NOTE:
Intentional tampering with emissions con-
trol systems can result in civil penalties
being assessed against you.WARNING!
A hot exhaust system can start a fire if you
park over materials that can burn. Such ma-
terials might be grass or leaves coming into
contact with your exhaust system. Do not park
or operate your vehicle in areas where your
exhaust system can contact anything that can
burn.
In unusual situations involving grossly malfunc-
tioning engine operation, a scorching odor may
suggest severe and abnormal catalyst over-
heating. If this occurs, stop the vehicle, turn off
the engine and allow it to cool. Service, includ-
ing a tuneup to manufacturer’s specifications,
should be obtained immediately.
To minimize the possibility of catalytic converter
damage:
• Do not shut off the engine or interrupt the
ignition, when the transmission is in gear and
the vehicle is in motion.
• Do not try to start the engine by pushing or
towing the vehicle. •
Do not idle the engine with any spark plug
wires disconnected or removed, such as
when diagnostic testing, or for prolonged
periods during very rough idle or malfunc-
tioning operating conditions.
Cooling System
WARNING!
You or others can be badly burned by hot
engine coolant (antifreeze) or steam from
your radiator. If you see or hear steam coming
from under the hood, do not 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 the engine coolant (antifreeze) protec-
tion every 12 months (before the onset of
freezing weather, where applicable). If the en-
gine coolant (antifreeze) is dirty or rusty in
appearance, the system should be drained,
flushed and refilled with fresh engine coolant
(antifreeze). Check the front of the A/C con-
denser for any accumulation of bugs, leaves,
308

Cavity Car-tridgeFuse Mini
Fuse Description
M7 20 Amp YellowPower Outlet #2
(Switchable)
M8 20 Amp
Yellow Front Heated
Seat & Steering
Wheel
M9 20 Amp
Yellow Rear Heated
Seats
M10 15 Amp
Blue Video/Universal
Garage Door
Opener
M11 10 Amp
Red Heating, Ventila-
tion & Air Condi-
tioning (Climate
Control System)
M12 30 Amp
Green Radio/Amplifier
M13 20 Amp
Yellow Instrument Clus-
ter
M14 20 Amp
Yellow Back Up Cam-
era–If
EquippedCavity Car-
tridgeFuse Mini
Fuse Description
M15 20 Amp YellowPower Seat
Module(s)/
Adaptive Cruise
Control/Audio
Telematics/
Daytime Run-
ning Lights
Relay/Air Sus-
pension Module/
Instrument Clus-
ter
M16 10 Amp RedOccupant Re-
straint Controller
M18 15 Amp
Blue Stop Lamp
M19 25 Amp
Natural Automatic Shut-
down 1 and 2
M20 15 Amp BlueInstrument Clus-
ter
M21 20 Amp YellowAutomatic Shut-
down 3Cavity Car-
tridgeFuse Mini
Fuse Description
M22 10 Amp RedHorns (Low/
High) – Right
M23 10 Amp
Red Horns (Low/
High) – Left
M24 25 Amp
Natural Rear Wiper
M25 20 Amp
Yellow Fuel Pump Mo-
tor Output/Diesel
Lift Pump (Ex-
port Only)
M26 10 Amp
Red Driver Door
Switch Bank
M27 10 Amp RedIgnition Switch/
Wireless Control
Module/Keyless
Entry Module
M28 15 Amp
Blue Powertrain
Controller/
Transmission
Controller
320