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•Windshield Washer Fluid Low Indicator
This telltale will turn on to indicate the wind-
shield washer fluid is low.
• Low Coolant Level Indicator
This telltale will turn on to indicate the vehicle
coolant level is low.
• Transmission Temperature Warning Telltale
This telltale indicates that the transmission
fluid temperature is running hot. This may
occur with severe usage, such as trailer towing.
If this telltale turns on, safely pull over and
stop the vehicle. Then, shift the transmission into NEU-
TRAL and run the engine at idle or faster until the light
turns off.CAUTION!
Continuous driving with the Transmission Tempera-
ture Warning Light illuminated will eventually cause
severe transmission damage or transmission failure.
WARNING!
If you continue operating the vehicle when the
Transmission Temperature Warning Light is illumi-
nated you could cause the fluid to boil over, come in
contact with hot engine or exhaust components and
cause a fire.
• Loose Fuel Filler Cap
This telltale will turn on to indicate that the fuel
filler cap may be loose.
4
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Trailer Tow
Push and release theUPorDOWN arrow
button until the Trailer Tow icon is highlighted.
Push and release the RIGHTarrow button and
the next screen will display the following
trailer trip information:
• Trailer Trip
• Trailer Brake
Audio
Push and release the UPorDOWN arrow button
until the Audio display icon is highlighted in the
DID. Push and release the RIGHTarrow button
to display the active source.
Stored Messages
Push and release the UParrow button until the
Messages display icon is highlighted in the
DID. This feature shows the number of stored
warning messages. Pushing the RIGHTarrow
button will allow you to see what the stored messages
are.
Screen Setup
Push and release the UPorDOWN arrow
button until the Screen Setup display icon is
highlighted in the DID. Push and release the
RIGHT arrow button to enter the Screen Setup
submenu. The Screen Setup feature allows you to change
what information is displayed in the instrument cluster
as well as the location that information is displayed.
4
UNDERSTANDING YOUR INSTRUMENT PANEL 253
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Setting NamesSetting Names Abbreviated
(Left Submenu Layer) Sub-Menus
(Right Submenu Layer)
22 Commercial Settings Commercial
•Aux Switches
• Power Take-Off
• PIN Setup
23 Air Suspension Display Alerts Air Susp. AlertsAll; Warnings Only
24 Aero Ride Height Mode Aero ModeOn; Off
25 Tire/Jack Mode Tire/Jack Mode On; Off
26 Transport Mode Transport Mode On; Off
27 Wheel Alignment Mode Wheel AlignmentOn; Off
28 Horn w/ Remote Lower Horn w/ Rmt LwrOn; Off
29 Lights w/ Remote Lower Lights w/ Rmt LwrOn; Off
30 Trailer Select Trailer SelectTrailer 1; Trailer 2; Trailer 3;
Trailer 4
31 Brake Type Brake TypeLight Electric; Heavy Electric;
Light EOH; Heavy EOH4
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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.
342 STARTING AND OPERATING
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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
the transmission. This condition is normal and will not
5
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The “Transfer Case Position Indicator Light” in the
instrument cluster will alert the driver that the vehicle is
in four-wheel drive and that the front and rear drive-
shafts are locked together. This light will illuminate when
the transfer case is shifted into either the 4H or 4L
position. There is no light for the 2H or NEUTRAL
positions on some models.
When operating your vehicle in 4L, the engine speed is
approximately three times that of the 2H or 4H 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 will adversely affect shifting and
can cause damage to the drivetrain.NOTE:
Do not attempt to make a shift while only the
front or rear wheels are spinning. The front and rear
driveshaft speeds must be equal for the shift to take
place. Shifting while only the front or rear wheels are
spinning can cause damage to the transfer case.
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.
NOTE: Delayed shifts out of four-wheel drive may be
experienced due to uneven tire wear, low or uneven tire
pressures, excessive vehicle loading, or cold tempera-
tures.
WARNING!
You or others could be injured or killed if you leave
the vehicle unattended with the transfer case in the
(Continued)
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3. When the shift is complete, the indicator light for theselected 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 notshift.
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.
When operating your vehicle in 4WD LOW, the engine
speed is approximately three times that of the 2WD or5
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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 occurs
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.).
362 STARTING AND OPERATING