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WARNING!
Do not coast in NEUTRAL and never turn off the
ignition to coast down a hill. These are unsafe practices
that limit your response to changing traffic or road
conditions. You might lose control of the vehicle and
have a collision.
CAUTION!
Towing the vehicle, coasting, or driving for any other
reason with the transmission in NEUTRAL can cause
severe transmission damage. Refer to “Recreational
Towing” in “Starting And Operating” and “Towing A
Disabled Vehicle” in “What To Do In Emergencies” for
further information.
DRIVE (D)
This range should be used for most city and highway
driving. It provides the smoothest upshifts and downshifts,
and the best fuel economy. The transmission automatically
upshifts through underdrive first, second, and third gears,
direct fourth gear and overdrive fifth and sixth gears. The
DRIVE position provides optimum driving characteristics
under all normal operating conditions. When frequent transmission shifting occurs (such as when
operating the vehicle under heavy loading conditions, in
hilly terrain, traveling into strong head winds, or while
towing a heavy trailer), use the Electronic Range Select
(ERS) shift control (refer to “Electronic Range Select (ERS)
Operation” in this section for further information) to select
a lower gear range. Under these conditions, using a lower
gear range will improve performance and extend transmis-
sion life by reducing excessive shifting and heat buildup.
If the transmission temperature exceeds normal operating
limits, the powertrain controller will modify the transmis-
sion shift schedule and expand the range of torque con-
verter clutch engagement. This is done to prevent trans-
mission 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.
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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.
Transmission
Gear Limit
Display12 3 456D
Actual Gear(s)
Allowed 1 1-2 1-3 1-4 1-5 1-6 1-6
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 descending
steep grades, be careful not to overspeed the engine.
Apply the brakes as needed to prevent engine over-
speed.
Overdrive Operation
The automatic transmission includes an electronically con-
trolled Overdrive (fifth and sixth gears). The transmission
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.
• The vehicle speed is sufficiently high.
• The driver is not heavily pressing the accelerator.
When To Use TOW/HAUL Mode
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent transmission shifting occurs,
push the TOW/HAUL switch to activate TOW/HAUL
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
148 STARTING AND OPERATING
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4. Reinstall cap onto DEF tank.
Filling The Def Tank In Cold Climates
Since DEF will begin to freeze at 12°F (-11°C), your vehicle
is equipped with an automatic DEF heating system. This
allows the DEF injection system to operate properly at
temperatures below 12°F (-11°C). If your vehicle is not in
operation for an extended period of time with tempera-
tures below 12°F (-11°C), the DEF in the tank may freeze. If
the tank is overfilled and freezes, it could be damaged.
Therefore, do not overfill the DEF tank.
The DEF tank on these vehicles is designed with a large
amount of full reserve. So the level sensor will indicate a
Full reading even before the tank is completely full. To put
it another way, there’s additional storage capacity in the
tank above the Full mark that’s not represented in the
gauge. You may not see any movement in the reading –
even after driving up to 2,000 miles in some cases.
The difference this makes varies by vehicle. Heavy-duty
pickup trucks have a 5.7-gallon (21.5 liter) tank that will
display a Full reading when about 90 percent full. This
means that drivers can consume at least 10 percent of a
truly full DEF tank without seeing any visible change in the
gauge reading. Chassis cabs have a larger 9-gallon (34 liter)
tank, and will display a Full reading when about 75 percentfull. So drivers can consume 25 percent of a truly full DEF
tank without seeing any visible change in the gauge
reading.
Extra care should be taken when filling with portable
containers to avoid overfilling. Note the level of the DEF
gauge in your instrument cluster. On pickup applications,
you may safely add a maximum of 2 gallons (7.5 liters) of
DEF from portable containers when your DEF gauge is
reading ½ full. On Chassis Cab applications a maximum of
2 gallons (7.5 liters) may be added when the DEF gauge is
reading ¾ full.
DIESEL EXHAUST FLUID
Your vehicle is equipped with a Selective Catalytic Reduc-
tion system to meet the very stringent diesel emissions
standards required by the Environmental Protection
Agency.
The purpose of the SCR system is to reduce levels of NOx
(oxides of nitrogen emitted from engines) that are harmful
to our health and the environment to a near-zero level.
Small quantities of Diesel Exhaust Fluid (DEF) is injected
into the exhaust upstream of a catalyst where, when
vaporized, it converts smog-forming nitrogen oxides
(NOx) into harmless nitrogen (N2) and water vapor (H2O),
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