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6. Modes
The airflow distribution mode can be adjusted so air
comes from the instrument panel outlets, floor outlets,
demister outlets and defrost outlets. The Mode settings
are as follows:•Panel Mode
Air comes from the outlets in the instrument
panel. Each of these outlets can be individu-
ally adjusted to direct the flow of air. The air
vanes of the center outlets and outboard outlets can
be moved up and down or side to side to regulate
airflow direction. There is a shut off wheel located
below the air vanes to shut off or adjust the amount
of airflow from these outlets.
• Bi-Level Mode
Air comes from the instrument panel outlets
and floor outlets. A slight amount of air is
directed through the defrost and side window
demister outlets. NOTE:
BI-LEVEL mode is designed under comfort con-
ditions to provide cooler air out of the panel outlets and
warmer air from the floor outlets.
•Floor Mode
Air comes from the floor outlets. A slight
amount of air is directed through the defrost
and side window demister outlets.
• Mix Mode
Air comes from the floor, defrost and side
window demister outlets. This mode works
best in cold or snowy conditions.
NOTE: The air conditioning compressor operates in MIX
and DEFROST modes even if the A/C button is not
pressed. This dehumidifies the air to help dry the wind-
shield. To improve fuel economy, utilize these modes
only when required.
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UNDERSTANDING YOUR INSTRUMENT PANEL 277
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direction. There is a shut off wheel located below the
air vanes to shut off or adjust the amount of airflow
from these outlets.
• Bi-Level Mode
Air comes from the instrument panel outlets
and floor outlets. A slight amount of air is
directed through the defrost and side window demis-
ter outlets.
NOTE: BI-LEVEL mode is designed under comfort con-
ditions to provide cooler air out of the panel outlets and
warmer air from the floor outlets.
• Floor Mode
Air comes from the floor outlets. A slight
amount of air is directed through the defrost
and side window demister outlets. •
Mix Mode
Air comes from the floor, defrost and side
window demist outlets. This mode works best
in cold or snowy conditions.
12. Climate Control OFF Button
Press and release this button to turn the Climate Control
ON/OFF.
13. Driver Temperature Control Down Button
Provides the driver with independent temperature con-
trol. Push the hard-key button for cooler temperature
settings or on the touchscreen, press and slide the soft-
key temperature bar towards the blue arrow soft-key for
cooler temperature settings.
NOTE: In Sync mode, this button will also automatically
adjust the passenger temperature setting at the same
time.
284 UNDERSTANDING YOUR INSTRUMENT PANEL
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STARTING AND OPERATING
CONTENTS
STARTING PROCEDURES ................294
▫ Normal Starting ...................... .294
▫ Automatic Transmission ................295
▫ Extreme Cold Weather
(Below –20°F or 29°C) .................295
▫ If Engine Fails To Start .................295
▫ After Starting ....................... .296
ENGINE BLOCK HEATER — IF EQUIPPED . . . .297
AUTOMATIC TRANSMISSION ............297
▫ Key Ignition Park Interlock ...............299 ▫
Brake/Transmission Shift Interlock System . . .300
▫ Six–Speed Automatic Transmission —
If Equipped ........................ .300
FOUR-WHEEL DRIVE OPERATION — IF
EQUIPPED ...........................311
▫ Manually Shifted Transfer Case —
If Equipped ......................... .312
▫ Shifting Procedure — Manually Shifted Transfer
Case ............................. .314
▫ Transfer Case Position Indicator Light ......315
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▫Electronically Shifted Transfer Case (Four-Position
Switch) — If Equipped .................316
▫ Shifting Procedure .....................320
LIMITED-SLIP DIFFERENTIAL .............322
DRIVING ON SLIPPERY SURFACES .........323
▫ Acceleration ........................ .323
▫ Traction ........................... .323
DRIVING THROUGH WATER .............324
▫ Flowing/Rising Water ..................324
▫ Shallow Standing Water .................324
POWER STEERING .....................326
▫ Power Steering Fluid Check ..............327
PARKING BRAKE ..................... .328
BRAKE SYSTEM ...................... .330
▫ Four-Wheel Anti-Lock Brake System ........331
▫ Hydraulic Brake Assist ..................332
ELECTRONIC BRAKE CONTROL SYSTEM . . . .333
▫ Anti-Lock Brake System (ABS) ............333
▫
Traction Control System (TCS) — If Equipped . .334
▫ Hill Start Assist (HSA) — If Equipped .......334
▫ Electronic Stability Control (ESC) —
If Equipped ........................ .338
▫ ESC Activation/Malfunction Indicator Light And
ESC OFF Indicator Light ................341
▫ Trailer Sway Control (TSC) — If Equipped . . .343
TIRE SAFETY INFORMATION .............344
▫ Tire Markings ....................... .344
290 STARTING AND OPERATING
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If the transmission temperature exceeds normal operat-
ing limits, the powertrain controller will modify the
transmission shift schedule and expand the range of
torque converter clutch engagement. This is done to
prevent transmission damage due to overheating.
If the transmission becomes extremely hot or is in danger
of overheating, the “Transmission Temperature Warning
Light” may illuminate and the transmission may operate
differently until the transmission cools down.
NOTE:Use caution when operating a heavily loaded
vehicle at low speeds (such as towing a trailer up a steep
grade, or in stop-and-go traffic) during hot weather. In
these conditions, torque converter slip can impose a
significant additional heat load on the cooling system.
Downshifting the transmission to the lowest possible
gear (when climbing a grade), or shifting to NEUTRAL
(when stopped in heavy traffic) can help to reduce this
excess heat generation. During cold temperatures, transmission operation may
be modified depending on engine and transmission
temperature as well as vehicle speed. This feature im-
proves warm up time of the engine and transmission to
achieve maximum efficiency. Engagement of the torque
converter clutch is inhibited until the transmission fluid
is warm (refer to the “Note” under “Torque Converter
Clutch” in this section). On models with 66RFE transmis-
sion, top overdrive gear is also inhibited until the trans-
mission fluid is warm, and during extremely cold tem-
peratures (-16°F [-27°C] or below), operation may briefly
be limited to first and direct gears only. On trucks with
AS66RC transmission, fifth and sixth gears may be
inhibited briefly on cold starts below 41°F (5°C), and
during very cold temperatures (-4°F [-20°C] or below),
operation may briefly be limited to third gear only.
During this condition, the ability of the vehicle to accel-
erate under heavily loaded conditions may be reduced.
306 STARTING AND OPERATING
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In all cases, normal operation will resume once the
transmission temperature has risen to a suitable level.
Transmission Limp Home Mode
Transmission function is monitored electronically for
abnormal conditions. If a condition is detected that could
result in transmission damage, Transmission Limp Home
Mode is activated. In this mode, the transmission remains
in fourth gear (for 66RFE transmission) or third gear (for
AS66RC transmission) regardless of which forward gear
is selected. If an AS66RC equipped truck enters Limp
Home Mode at highway speeds, it will initially engage
fifth gear, until the vehicle slows to a speed where third
gear can be engaged. PARK, REVERSE, and NEUTRAL
will continue to operate. The Malfunction Indicator Light
(MIL) may be illuminated. Limp Home Mode allows the
vehicle to be driven to an authorized dealer for service
without damaging the transmission.In the event of a momentary problem, the transmission
can be reset to regain all forward gears by performing the
following steps:
1. Stop the vehicle.
2. Shift the transmission into PARK.
3. Turn the ignition switch to the OFF position.
4. Wait approximately 10 seconds.
5. Restart the engine.
6. Shift into the desired gear range. If the problem is no
longer detected, the transmission will return to normal
operation.
NOTE: Even if the transmission can be reset, we recom-
mend that you visit your authorized dealer at your
earliest possible convenience. Your authorized dealer has
diagnostic equipment to determine if the problem could
recur.
5
STARTING AND OPERATING 307
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mode. This will improve performance and reduce the
potential for transmission overheating or failure due to
excessive shifting. When operating in TOW/HAUL mode,
transmission upshifts are delayed, and the transmission
will automatically downshift (for engine braking) during
steady braking maneuvers.The “TOW/HAUL Indicator Light” will illuminate in the
instrument cluster to indicate that TOW/HAUL mode
has been activated. Pressing the switch a second time
restores normal operation. Normal operation is always
the default at engine start-up. If TOW/HAUL mode is
desired, the switch must be pressed 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.
TOW/HAUL Switch
310 STARTING AND OPERATING
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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
the transmission. This condition is normal and will not
cause damage to the transmission. The torque con-
verter will refill within five seconds after starting the
engine.
FOUR-WHEEL DRIVE OPERATION — IF
EQUIPPED
Four-wheel drive trucks are equipped with either a
manually shifted transfer case or an electronically shifted
transfer case. Refer to the operating instructions for your
transfer case, located in this section for further informa-
tion.
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