Overdrive Operation
The automatic transmission includes an elec-
tronically controlled Overdrive (fifth gear for
3.6L and 3.0L Diesel engine, fourth and fifth
gears for 5.7L engine). The transmission will
automatically shift to Overdrive, if the following
conditions are present:
•the shift lever is in DRIVE;
• the engine coolant has reached normal op-
erating temperature;
• vehicle speed is above approximately
30 mph (48 km/h);
• the TOW/HAUL switch has not been acti-
vated;
• transmission has reached normal operating
temperature.
NOTE:
If the vehicle is started in extremely cold
temperatures, 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 tem-
perature has risen to a suitable level. Refer to the “Note” under “Torque Converter
Clutch” in this section.
During cold temperature operation you may
notice delayed upshifts, depending on en-
gine and transmission temperature. This
feature improves the warm-up time of the
engine and transmission.
If the transmission temperature gets ex-
tremely hot, the transmission will automati-
cally select the most desirable gear for op-
eration at this temperature. If the
transmission temperature becomes hot
enough, the “TRANSMISSION OVER TEMP”
message may display, and the transmission
may downshift out of Overdrive until the
transmission cools down. After cool down,
the transmission will resume normal opera-
tion.
The transmission will downshift from Overdrive,
to the most desirable gear, if the accelerator
pedal is fully pressed at vehicle speeds above
approximately 35 mph (56 km/h).
When to Use TOW/HAUL Mode –
If Equipped
When driving in hilly areas, towing a trailer,
carrying a heavy load, etc., and frequent trans-
mission shifting occurs, press the TOW/HAUL
switch. This will improve performance and re-
duce the potential for transmission overheating
or failure due to excessive shifting. When oper-
ating in TOW/HAUL mode, the transmission will
shift into direct gear and Overdrive will be
enabled under steady cruise conditions.
TOW/HAUL Switch
208
Selec-Terrain™ consists of the following posi-
tions:
•Sport – Dry weather, on-road calibration.
Only available in 4WD High range. Perfor-
mance based tuning that provides a rear
wheel drive feel but with improved handling
and acceleration over a two-wheel drive ve-
hicle. The Electronic Stability Control will set
to allow more driver control of vehicle while
maintaining safe handling controls. The ve-
hicle will lower (if equipped with Air Suspen-
sion) to Aero Mode in High Range. 4WD Low
is not available in SPORT mode, if 4WD Low
is selected the Selec-Terrain™ will automati-
cally switch back to AUTO.
• Snow – Tuning set for additional stability in
inclement weather. Use on and off road on
loose traction surfaces such as snow. When
in Snow mode (depending on certain oper-
ating conditions), the transmission may use
second gear (rather than first gear) during
launches, to minimize wheel slippage. If
equipped with air suspension, the level will
change to Normal Ride Height (NRH) if the transfer case is in high range. The level will
change to Off-Road 1 if the transfer case is in
Low range.
• Auto – Fully automatic full time four-wheel
drive operation can be used on and off road.
Balances traction with seamless steering
feel to provide improved handling and accel-
eration over two-wheel drive vehicles. If
equipped with air suspension, the level will
change to NRH.
• Sand/Mud – Off road calibration for use on
low traction surfaces such as mud, sand, or
wet grass. Driveline is maximized for trac-
tion. Some binding may be felt on less for-
giving surfaces. The electronic brake con-
trols are set to limit traction control
management of throttle and wheel spin. If
equipped with air suspension, the level will
change to Off-Road 1.
• Rock – Off-road calibration only available in
4WD Low range. The vehicle is raised (if
equipped with Air Suspension) for improved
ground clearance. Traction based tuning
with improved steer-ability for use on high
traction off-road surfaces. Activates the Hill Descent Control for steep downhill control.
Use for low speed obstacles such as large
rocks, deep ruts, etc. If equipped with air
suspension, the vehicle level will change to
Off-Road 2. If the Selec-Terrain™ switch is in
ROCK mode, and the transfer case is
switched from 4WD Low to 4WD High, the
Selec-Terrain™ system will return to AUTO.
Electronic Vehicle Information
Center (EVIC) Display Messages
When the appropriate conditions exist, a mes-
sage will appear in the EVIC display. Refer to
“Electronic Vehicle Information Center (EVIC)”
in “Understanding Your Instrument Panel” for
further information.
QUADRA-LIFT™ — IF EQUIPPED
Description
The Quadra-Lift™ air suspension system pro-
vides full time load leveling capability along
with the benefit of being able to adjust vehicle
height by the push of a button.
214
speed remains between 15 mph (24 km/h)
and 25 mph (40 km/h) for greater than
60 seconds, or the vehicle speed exceeds
25 mph (40 km/h) the Park Mode change will
be cancelled. To exit Park Mode, press the
“Up” button once while in Park Mode or drive
the vehicle over 15 mph (24 km/h).
The Selec-Terrain™ switch will automatically
change the vehicle to the proper height based
on the position of the Selec-Terrain™ switch.
The height can be changed from the default
Selec-Terrain™ setting by normal use of the air
suspension buttons. Refer to “Selec-Terrain™”
in “Starting and Operating” for further informa-
tion.
The system requires that the engine be running
for all changes. When lowering the vehicle all of
the doors, including the liftgate, must be
closed. If a door is opened at any time while the
vehicle is lowering the change will not be
completed until the open door(s) is closed.
The Quadra-Lift™ air suspension system uses
a lifting and lowering pattern which keeps the
headlights from incorrectly shining into oncom-
ing traffic. When raising the vehicle, the rear of the vehicle will move up first and then the front.
When lowering the vehicle, the front will move
down first and then the rear.
After the engine is turned off, it may be noticed
that the air suspension system operates briefly,
this is normal. The system is correcting the
position of the vehicle to ensure a proper
appearance.
To assist with changing a spare tire, the
Quadra-Lift™ air suspension system has a fea-
ture which allows the automatic leveling to be
disabled. Press and hold both the “Up” and
“Down” buttons simultaneously between 5 and
10 seconds, a message will appear in the EVIC
stating leveling has been disabled immediately
after both buttons have been released. Refer to
“Electronic Vehicle Information Center (EVIC)”
in “Understanding Your Instrument Panel” for
further information. Driving the vehicle over
5 mph (8 km/h) will return the air suspension to
normal operation. Refer to “Jacking and Tire
Changing” in “What To Do In Emergencies” for
further information.WARNING!
The air suspension system uses a high pres-
sure volume of air to operate the system. To
avoid personal injury or damage to the sys-
tem, see your authorized dealer for service.
Electronic Vehicle Information
Center (EVIC) Display Messages
When the appropriate conditions exist, a mes-
sage will appear in the EVIC display. Refer to
“Electronic Vehicle Information Center (EVIC)”
in “Understanding Your Instrument Panel” for
further information.
An audible chime will be heard whenever a
system error has been detected.
OperationThe indicator lamps 3 through 6 will illuminate
to show the current position of the vehicle.
Flashing indicator lamps will show a position
which the system is working to achieve. When
raising, if multiple indicator lamps are flashing
on the “Up” button, the highest flashing indica-
tor lamp is the position the system is working to
achieve. When lowering, if multiple indicators
216
When descending mountains or hills, repeated
braking can cause brake fade with loss of
braking control. Avoid repeated heavy braking
by downshifting the transmission whenever
possible.
After Driving Off-RoadOff-road operation puts more stress on your
vehicle than does most on-road driving. After
going off-road, it is always a good idea to
check for damage. That way you can get any
problems taken care of right away and have
your vehicle ready when you need it.
•Completely inspect the underbody of your
vehicle. Check tires, body structure, steer-
ing, suspension, and exhaust system for
damage.
• Inspect the radiator for mud and debris and
clean as required.
• Check threaded fasteners for looseness,
particularly on the chassis, drivetrain com-
ponents, steering, and suspension. Re-
tighten them, if required, and torque to the
values specified in the Service Manual. •
Check for accumulations of plants or brush.
These things could be a fire hazard. They
might hide damage to fuel lines, brake hoses,
axle pinion seals, and propeller shafts.
• After extended operation in mud, sand, wa-
ter, or similar dirty conditions, have the ra-
diator, fan, brake rotors, wheels, brake lin-
ings, and axle yokes inspected and cleaned
as soon as possible.
WARNING!
Abrasive material in any part of the brakes
may cause excessive wear or unpredictable
braking. You might not have full braking power
when you need it to prevent a collision. If you
have been operating your vehicle in dirty
conditions, get your brakes checked and
cleaned as necessary.
• If you experience unusual vibration after
driving in mud, slush or similar conditions,
check the wheels for impacted material. Im-
pacted material can cause a wheel imbal-
ance and freeing the wheels of it will correct
the situation.
POWER STEERING
3.6L Engine and 3.0L Diesel Engine
Your vehicle is equipped with an electro-
hydraulic power steering system that will give
you good vehicle response and increased ease
of maneuverability in tight spaces. The system
will vary its assist to provide light efforts while
parking and good feel while driving. If the
electro-hydraulic power steering system expe-
riences a fault that prevents it from providing
power steering assist, then the system will
provide mechanical steering capability.
CAUTION!
Extreme steering maneuvers may cause the
electrically driven pump to reduce or stop
power steering assistance in order to prevent
damage to the system. Normal operation will
resume once the system is allowed to cool.
If the “SERVICE POWER STEER-
ING SYSTEM” message and a
flashing icon are displayed on the
EVIC screen, it indicates that the
vehicle needs to be taken to the
220
dealer for service. It is likely the vehicle has lost
power steering assistance. Refer to “Electronic
Vehicle Information (EVIC)” in “Understanding
Your Instrument Panel” for further information.
If the “POWER STEERING SYSTEM OVER
TEMP” message and an icon are displayed on
the EVIC screen, it indicates that extreme steer-
ing maneuvers may have occurred, which
caused an over temperature condition in the
power steering system. You will lose power
steering assistance momentarily until the over
temperature condition no longer exists. Once
driving conditions are safe, then pull over and
let vehicle idle for a few moments until the light
turns off. Refer to “Electronic Vehicle Informa-
tion (EVIC)” in “Understanding Your Instrument
Panel” for further information.
NOTE:
•Even if power steering assistance is no
longer operational, it is still possible to
steer the vehicle. Under these conditions
there will be a substantial increase in
steering effort, especially at very low ve-
hicle speeds and during parking maneu-
vers. •
If the condition persists, see your autho-
rized dealer for service.
5.7L EngineThe standard power steering system will give
you good vehicle response and increased ease
of maneuverability in tight spaces. The system
will provide mechanical steering capability if
power assist is lost.
If for some reason the power assist is inter-
rupted, it will still be possible to steer your
vehicle. Under these conditions, you will ob-
serve a substantial increase in steering effort,
especially at very low vehicle speeds and
during parking maneuvers.
NOTE:
• Increased noise levels at the end of the
steering wheel travel are considered nor-
mal and do not indicate that there is a
problem with the power steering system.
• Upon initial start-up in cold weather, the
power steering pump may make noise for
a short amount of time. This is due to the
cold, thick fluid in the steering system. This noise should be considered normal,
and it does not in any way damage the
steering system.WARNING!
Continued operation with reduced power
steering assist could pose a safety risk to
yourself and others. Service should be ob-
tained as soon as possible.
CAUTION!
Prolonged operation of the steering system at
the end of the steering wheel travel will in-
crease the steering fluid temperature and it
should be avoided when possible. Damage to
the power steering pump may occur.
Power Steering Fluid CheckChecking the power steering fluid level at a
defined service interval is not required. The
fluid should only be checked if a leak is sus-
pected, abnormal noises are apparent, and/or
the system is not functioning as anticipated.
Coordinate inspection efforts through an autho-
rized dealer.
221
arrows on the side wall of the tire. The full size
spare tire is mounted as a direct replacement
for the right side of the vehicle. For a flat tire on
the left side of the vehicle, the full size spare
can be used as mounted. If this is required,
correct the rotation as soon as possible to
restore optimum wet performance.
TIRE ROTATION
RECOMMENDATIONS
Non-Directional Tires Only
Tires on the front and rear axles of vehicles
operate at different loads and perform different
steering, handling, and braking functions. For
these reasons, they wear at unequal rates.
These effects can be reduced by timely rotation
of tires. The benefits of rotation are especially
worthwhile with aggressive tread designs such
as those on On/Off-Road type tires. Rotation
will increase tread life, help to maintain mud,
snow, and wet traction levels, and contribute to
a smooth, quiet ride.Refer to the “Maintenance Schedule” for the
proper maintenance intervals. More frequent
rotation is permissible if desired. The reasons
for any rapid or unusual wear should be cor-
rected prior to rotation being performed.
NOTE:
The premium Tire Pressure Monitor System
will automatically locate the pressure values
displayed in the correct vehicle position
following a tire rotation.
The suggested rotation method is the “forward-
cross” shown in the following diagram.
TIRE PRESSURE MONITOR SYSTEM
(TPMS)
The Tire Pressure Monitoring System (TPMS)
will warn the driver of a low tire pressure based
on the vehicle recommended cold tire pressure.
The tire pressure will vary with temperature by
about 1 psi (7 kPa) for every 12°F (–11°C). This
means that when the outside temperature de-
creases, the tire pressure will decrease. Tire
pressure should always be set based on cold
inflation tire pressure. This is defined as the tire
pressure after the vehicle has not been driven
for at least three hours, or driven less than
1 mile (1.6 km) after a three-hour period.
Refer
to “Tires – General Information” in “Starting
and Operating” for information on how to
properly inflate the vehicle’s tires. The tire
pressure will also increase as the vehicle is
driven - this is normal and there should be no
adjustment for this increased pressure.
The TPMS will warn the driver of a low tire
pressure if the tire pressure falls below the low
pressure warning threshold for any reason,
including low temperature effects, or natural
pressure loss through the tire.
Tire Rotation
234
The TPMS will continue to warn the driver of low
tire pressure as long as the condition exists,
and will not turn off until the tire pressure is at or
above recommended cold tire pressure. Once
the “TPM Telltale Light” and the “TIRE LOW
PRESSURE” message appears, the tire pres-
sure must be increased to the recommended
cold tire pressure in order for the ”TPM Telltale
Light” and the “TIRE LOW PRESSURE” mes-
sage to be turned off. The system will automati-
cally update and the “TPM Telltale Light” and
the “TIRE LOW PRESSURE” message will turn
off once the updated tire pressures have been
received. The vehicle may need to be driven for
up to 20 minutes above 15 mph (24 km/h) to
receive this information.
For example, your vehicle has a recommended
cold (parked for more than three hours) tire
pressure of 33 psi (227 kPa). If the ambient
temperature is 68°F (20°C) and the measured
tire pressure is 28 psi (193 kPa), a temperature
drop to 20°F (-7°C) will decrease the tire pres-
sure to approximately 24 psi (165 kPa). This tire
pressure is sufficiently low enough to display
the “TPM Telltale Light” and the “TIRE LOW
PRESSURE” message. Driving the vehicle maycause the tire pressure to rise to approximately
28 psi (193 kPa), but the “TPM Telltale Light”
and the “TIRE LOW PRESSURE” message will
still display. In this situation, the “TPM Telltale
Light” and the “TIRE LOW PRESSURE” mes-
sage will turn OFF only after the tires have been
inflated to the vehicle’s recommended cold tire
pressure value.
CAUTION!
•
The TPMS has been optimized for the
original equipment tires and wheels. TPMS
pressures have been established for the
tire size equipped on your vehicle. Unde-
sirable system operation or sensor damage
may result when using replacement equip-
ment that is not of the same size, type,
and/or style. Aftermarket wheels can cause
sensor damage. Do not use aftermarket tire
sealants or balance beads if your vehicle is
equipped with a TPMS, as damage to the
sensors may result.
(Continued)
CAUTION!(Continued)
• After inspecting or adjusting the tire pres-
sure always reinstall the valve stem cap.
This will prevent moisture and dirt from
entering the valve stem, which could dam-
age the Tire Pressure Monitoring Sensor.
NOTE:
• The TPMS is not intended to replace nor-
mal tire care and maintenance, or to pro-
vide warning of a tire failure or condition.
• The TPMS should not be used as a tire
pressure gauge while adjusting your tire
pressure.
• Driving on a significantly under-inflated
tire causes the tire to overheat and can
lead to tire failure. Under-inflation also
reduces fuel efficiency and tire tread life,
and may affect the vehicle’s handling and
stopping ability.
• The TPMS is not a substitute for proper
tire maintenance, and it is the driver’s
responsibility to maintain correct tire
pressure using an accurate tire gauge,
even if under-inflation has not reached
235
the level to trigger the display of the “TPM
Telltale Light” and the “TIRE LOW PRES-
SURE” message.
• Seasonal temperature changes will affect
tire pressure, and the TPMS will monitor
the actual tire pressure in the tire.
Base SystemThe Tire Pressure Monitor System (TPMS) uses
wireless technology with wheel rim-mounted
electronic sensors to monitor tire pressure lev-
els. Sensors, mounted to each wheel as part of
the valve stem, transmit tire pressure readings
to the Receiver Module.
NOTE:
It is particularly important, for you to regu-
larly check the tire pressure in all of your
tires, and to maintain the proper pressure.
The TPMS consists of the following compo-
nents:
• Receiver Module
• Four Tire Pressure Monitoring Sensors
• Tire Pressure Monitoring Telltale Light A low spare tire will not cause the “Tire Pressure
Monitoring Telltale Light” to illuminate, a warn-
ing message to appear, or the chime to sound.
The “Tire Pressure Monitoring Telltale
Light” will illuminate in the instrument
cluster, a “TIRE LOW PRESSURE”
message will display in the instrument
cluster for 5 seconds, and an audible chime will
be activated, when one or more of the four
active road tire pressures are low. Should this
occur, you should stop as soon as possible,
check the inflation pressure of each tire on your
vehicle, and inflate each tire to the vehicle’s
recommended cold placard pressure value.
The system will automatically update and the
“Tire Pressure Monitoring Telltale Light” will
extinguish, once the updated tire pressures
have been received. The vehicle may need to
be driven for up to 20 minutes above 15 mph
(24 km/h) to receive this information.
The “Tire Pressure Monitoring Telltale Light” will
flash on and off for 75 seconds, and remain on
solid when a system fault is detected. In addi-
tion, a “SERVICE TPM SYSTEM” message may
be displayed for approximately 5 seconds
when a system fault is detected, and a chime will sound. If the ignition switch is cycled, this
sequence will repeat, providing the system
fault still exists. The “Tire Pressure Monitoring
Telltale Light” will turn off when the fault condi-
tion no longer exists. A system fault can occur
by any of the following:
1. Jamming due to electronic devices or driv-
ing next to facilities emitting the same Radio
Frequencies as the TPM sensors.
2. Installing some form of aftermarket window
tinting that affects radio wave signals.
3. Lots of snow or ice around the wheels or
wheel housings.
4. Using tire chains on the vehicle.
5. Using wheels/tires not equipped with TPM
sensors.
NOTE:
There is no tire pressure monitoring sensor
in the spare tire. The TPMS will not be able to
monitor the tire pressure. If you install the
spare tire, in place of a road tire, that has a
pressure below the low-pressure warning
limit, upon the next ignition switch cycle, a
chime will sound, a “TIRE LOW PRESSURE”
236