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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 a collision or
personal injury.
NOTE: To select the proper gear position for maximum
deceleration (engine braking), simply push and hold the
ERS (-) switch. The transmission will shift to the range
from which the vehicle can best be slowed down.
CAUTION!When using ERS for engine braking while descend-
ing steep grades, be careful not to overspeed the
engine. Apply the brakes as needed to prevent en-
gine overspeed. Overdrive Operation
The automatic transmission includes an electronically
controlled Overdrive (fifth and sixth gears). The trans-
mission will automatically shift into Overdrive if the
following conditions are present:
• The gear selector is in the DRIVE position.
• The transmission fluid has reached an adequate tem-
perature.
• The engine coolant has reached an adequate tempera-
ture.
• Vehicle speed is sufficiently high.
• The TOW/HAUL switch has not been activated.
• The driver is not heavily pressing the accelerator. 5STARTING AND OPERATING 417
Page 421 of 675

desired, the switch must be pushed each time the engine
is started.
WARNING!Do not use the “TOW/HAUL” feature when driving
in icy or slippery conditions. The increased engine
braking can cause the rear wheels to slide, and the
vehicle to swing around with the possible loss of
vehicle control, which may cause an accident possi-
bly resulting in personal injury or death.
Torque Converter Clutch
A feature designed to improve fuel economy has been
included in the automatic transmission on your vehicle.
A clutch within the torque converter engages automati-
cally at calibrated speeds. This may result in a slightly
different feeling or response during normal operation in the upper gears. When the vehicle speed drops or during
some accelerations, the clutch automatically disengages.
NOTE:
• The torque converter clutch will not engage (and
66RFE-equipped trucks will not shift to sixth gear),
until the transmission fluid and engine coolant are
warm [usually after 1 to 3 miles (2 to 5 km) of driving].
Because engine speed is higher when the torque con-
verter clutch is not engaged, it may seem as if the
transmission is not shifting properly when cold. This is
normal. Using the Electronic Range Select (ERS) shift
control, when the transmission is sufficiently warm,
will demonstrate that the transmission is able to shift
into and out of Overdrive.
• If the vehicle has not been driven for several days, the
first few seconds of operation after shifting the trans-
mission into gear may seem sluggish. This is due to the
fluid partially draining from the torque converter into 5STARTING AND OPERATING 419
Page 427 of 675

WARNING!You or others could be injured or killed if you leave
the vehicle unattended with the transfer case in the
NEUTRAL position without first fully engaging the
parking brake. The transfer case NEUTRAL position
disengages both the front and rear drive shafts from
the powertrain and will allow the vehicle to roll,
even if the transmission is in PARK. The parking
brake should always be applied when the driver is
not in the vehicle.
For additional information on the appropriate use of each
transfer case mode position, see the information below:
2H
Rear-Wheel Drive High Range — This range is for
normal street and highway driving on dry hard surfaced
roads. 4H
Four-Wheel Drive High Range — This range locks the
front and rear driveshafts together forcing the front and
rear wheels to rotate at the same speed. Additional
traction for loose, slippery road surfaces only.
Neutral (N)
Neutral — This range disengages the front and rear
driveshafts from the powertrain. To be used for flat
towing behind another vehicle. Refer to “Recreational
Towing” in “Starting And Operating” for further infor-
mation.
4L
Four-Wheel Drive Low Range — This range locks the
front and rear driveshafts together forcing the front and
rear wheels to rotate at the same speed. Additional 5STARTING AND OPERATING 425
Page 431 of 675

3. When the shift is complete, the indicator light for the
selected position will stop flashing and remain ON.
If One Or More Shift Conditions Are Not Met:
1. The indicator light for the current position will remain
ON.
2. The newly selected position indicator light will con-
tinue to flash.
3. The transfer case will not shift.
NOTE: Before retrying a selection, make certain that all
the necessary requirements for selecting a new transfer
case position have been met. To retry the selection, turn
the control knob back to the current position, wait five
seconds, and retry selection. To find the shift require-
ments, refer to the Shifting Procedure for your transfer
case, located in this section. The “SVC 4WD Warning Light” monitors the electronic
shift four-wheel drive system. If this light remains on
after engine start up or illuminates during driving, it
means that the four-wheel drive system is not function-
ing properly and that service is required.
WARNING!Always engage the parking brake when powering
down the vehicle if the “SVC 4WD Warning Light” is
illuminated. Not engaging the parking brake may
allow the vehicle to roll, which may cause personal
injury.
NOTE: Do not attempt to make a shift while only the
front or rear wheels are spinning, as this can cause
damage to driveline components. 5STARTING AND OPERATING 429
Page 432 of 675

When operating your vehicle in 4WD LOW, the engine
speed is approximately three times that of the 2WD or
4WD LOCK positions at a given road speed. Take care
not to overspeed the engine and do not exceed 25 mph
(40 km/h).
Proper operation of four-wheel drive vehicles depends
on tires of equal size, type and circumference on each
wheel. Any difference in tire size can cause damage to the
drivetrain.
Because four-wheel drive provides improved traction,
there is a tendency to exceed safe turning and stopping
speeds. Do not go faster than road conditions permit.
WARNING!You or others could be injured or killed if you leave
the vehicle unattended with the transfer case in the (Continued) WARNING! (Continued)NEUTRAL position without first fully engaging the
parking brake. The transfer case NEUTRAL position
disengages both the front and rear drive shafts from
the powertrain and will allow the vehicle to roll,
even if the transmission is in PARK. The parking
brake should always be applied when the driver is
not in the vehicle.
For additional information on the appropriate use of each
transfer case mode position, see the information below:
2WD
Rear Wheel Drive High Range — This range is for normal
street and highway driving on dry, hard surfaced roads.
4WD LOCK
Four-Wheel Drive Lock Range — This range maximizes
torque to the front driveshaft, forcing the front and rear430 STARTING AND OPERATING
Page 436 of 675

LIMITED-SLIP DIFFERENTIAL
The limited-slip differential provides additional traction
on snow, ice, mud, sand and gravel, particularly when
there is a difference between the traction characteristics
of the surface under the right and left rear wheels. During
normal driving and cornering, the limited-slip unit per-
forms similarly to a conventional differential. On slip-
pery surfaces, however, the differential delivers more of
the driving effort to the rear wheel having the better
traction.
The limited-slip differential is especially helpful during
slippery driving conditions. With both rear wheels on a
slippery surface, a slight application of the accelerator
will supply maximum traction. When starting with only
one rear wheel on an excessively slippery surface, slight
momentary application of the parking brake may be
necessary to gain maximum traction. WARNING!On vehicles equipped with a limited-slip differential
never run the engine with one rear wheel off the
ground since the vehicle may drive through the rear
wheel remaining on the ground. You could lose
control of the vehicle.
Care should be taken to avoid sudden accelerations when
both rear wheels are on a slippery surface. This could
cause both rear wheels to spin, and allow the vehicle to
slide sideways on the crowned surface of a road or in a
turn.
DRIVING ON SLIPPERY SURFACES
Acceleration
Rapid acceleration on snow covered, wet, or other slip-
pery surfaces may cause the driving wheels to pull
erratically to the right or left. This phenomenon occurs434 STARTING AND OPERATING
Page 437 of 675

when there is a difference in the surface traction under
the rear (driving) wheels.
WARNING!Rapid acceleration on slippery surfaces is dangerous.
Unequal traction can cause sudden pulling of the rear
wheels. You could lose control of the vehicle and
possibly have a collision. Accelerate slowly and
carefully whenever there is likely to be poor traction
(ice, snow, wet mud, loose sand, etc.).
Traction
When driving on wet or slushy roads, it is possible for a
wedge of water to build up between the tire and road
surface. This is known as hydroplaning and may cause
partial or complete loss of vehicle control and stopping
ability. To reduce this possibility, the following precau-
tions should be observed: • Slow down during rainstorms or when the roads are
slushy.
• Slow down if the road has standing water or puddles.
• Replace tires when tread wear indicators first become
visible.
• Keep tires properly inflated.
• Maintain sufficient distance between your vehicle and
the vehicle in front of you to avoid a collision in a
sudden stop.
Your vehicle may be equipped with a Limited Slip
Differential (LSD) that reduces, but does not eliminate,
the amount of wheel slip across a given axle for im-
proved handling. 5STARTING AND OPERATING 435
Page 438 of 675

DRIVING THROUGH WATER
Driving through water more than a few inches/
centimeters deep will require extra caution to ensure
safety and prevent damage to your vehicle.
Flowing/Rising Water
WARNING!Do not drive on or across a road or path where water
is flowing and/or rising (as in storm run-off). Flow-
ing water can wear away the road or path’s surface
and cause your vehicle to sink into deeper water.
Furthermore, flowing and/or rising water can carry
your vehicle away swiftly. Failure to follow this
warning may result in injuries that are serious or
fatal to you, your passengers, and others around you. Shallow Standing Water
Although your vehicle is capable of driving through
shallow standing water, consider the following Cautions
and Warnings before doing so.
WARNING!• Driving through standing water limits your vehi-
cle’s traction capabilities. Do not exceed 5 mph
(8 km/h) when driving through standing water.
• Driving through standing water limits your vehi-
cle’s braking capabilities, which increases stopping
distances. Therefore, after driving through stand-
ing water, drive slowly and lightly press on the
brake pedal several times to dry the brakes.
• Failure to follow these warnings may result in
injuries that are serious or fatal to you, your pas-
sengers, and others around you.436 STARTING AND OPERATING