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Transmission Temperature Indicator Light
Yellow Tell-
tale Light What It Means
Transmission Temperature Indicator Light
This light indicates that the transmission fluid temperature is running hot. This may occur with
severe usage, such as trailer towing. If this light turns on, safely pull over and stop the vehicle.
Then, shift the transmission into NEUTRAL and run the engine at idle or faster until the light
turns off.258 UNDERSTANDING YOUR INSTRUMENT PANEL
Page 261 of 675
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.
Rear Fog Light Indicator — If Equipped
Yellow Telltale
Light What It Means
Rear Fog Light Indicator
This indicator will illuminate when the rear fog lights are on. 4UNDERSTANDING YOUR INSTRUMENT PANEL 259
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• Doors Open
• Gear Not Available
• Shift Not Allowed
• Shift to Neutral then Drive or Reverse
• Automatic Unavailable Use Autostick Service Req.
• Transmission Getting Hot Press Brake
• Trans. Hot Stop Safely Shift to Park Wait to Cool
• Transmission Cool Ready to Drive
• Trailer Brake Disconnected
• Service Transmission
• Service Shifter
• Engage Park Brake to Prevent Rolling
• Transmission Too cold Idle with Engine On • Washer Fluid Low
• Autostop Duration – If Equipped
The Reconfigurable Telltales section is divided into the
white telltales area on the right, yellow telltales in the
middle, and red telltales on the left.
EVIC Selectable Menu Items
Push and release the UP or DOWN arrow but-
tons until the desired Selectable Menu item is high-
lighted in the EVIC.
Speedometer Menu Item
Push and release the UP or DOWN arrow button
until the speedometer menu item is highlighted in the
EVIC. Push and release the RIGHT arrow button
to cycle the display between MPH and km/h.276 UNDERSTANDING YOUR INSTRUMENT PANEL
Page 283 of 675

• Door Open
• Doors Open
• Gear Not Available
• Shift Not Allowed
• Shift to Neutral then Drive or Reverse
• Automatic Unavailable Use Autostick Service Req.
• Transmission Getting Hot Press Brake
• Trans. Hot Stop Safely Shift to Park Wait to Cool
• Transmission Cool Ready to Drive
• Trailer Brake Disconnected
• Service Transmission
• Service Shifter
• Engage Park Brake to Prevent Rolling • Transmission Too cold Idle with Engine On
• Washer Fluid Low
• Autostop Duration – If Equipped
The Reconfigurable Telltales section is divided into the
white telltales area on the right, yellow telltales in the
middle, and red telltales on the left.
Screen Setup Menu Item
Push and release the UP or DOWN arrow button
until the Screen Setup menu item is highlighted in the
EVIC. 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. 4UNDERSTANDING YOUR INSTRUMENT PANEL 281
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• Doors Open
• Gear Not Available
• Shift Not Allowed
• Shift to Neutral then Drive or Reverse
• Automatic Unavailable Use Autostick Service Req.
• Transmission Getting Hot Press Brake
• Trans. Hot Stop Safely Shift to Park Wait to Cool
• Transmission Cool Ready to Drive
• Trailer Brake Disconnected
• Service Transmission
• Service Shifter
• Engage Park Brake to Prevent Rolling
• Transmission Too cold Idle with Engine On • Washer Fluid Low
• Autostop Duration – If Equipped
The Reconfigurable Telltales section is divided into the
white telltales area on the right, yellow telltales in the
middle, and red telltales on the left.
DID Selectable Menu Items
Push and release the UP or DOWN arrow but-
tons until the desired Selectable Menu icon/title is
highlighted in the DID.
Digital Speedometer
Push and release the UP or DOWN ar-
row button until the Digital display icon is
highlighted in the DID. Push and release the
RIGHT arrow button to change the dis-
play between mph and km/h.296 UNDERSTANDING YOUR INSTRUMENT PANEL
Page 416 of 675

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 transmission, top overdrive gear
is also inhibited until the transmission fluid is warm, and
during extremely cold temperatures (-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 tempera-
tures (-4°F [-20°C] or below), operation may briefly be
limited to third gear only. During this condition, the
ability of the vehicle to accelerate under heavily loaded414 STARTING AND OPERATING
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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
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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