— Cargo Light — If Equipped
The cargo light will illuminate when the cargo light is
activated by pushing the cargo light button on the head-
light switch.
— 4WD Low Indicator Light — If Equipped
This light alerts the driver that the vehicle is in the
four-wheel drive LOW mode. The front and rear drive-
shafts are mechanically locked together forcing the front
and rear wheels to rotate at the same speed. Low range
provides a greater gear reduction ratio to provide increased
torque at the wheels.
Refer to “Four-Wheel Drive Operation — If Equipped” in
“Starting And Operating” for further information on four-
wheel drive operation and proper use.
– 4WD Indicator Light — If Equipped
This light alerts the driver that the vehicle is in the
four-wheel drive mode, and the front and rear driveshafts
are mechanically locked together forcing the front and rear
wheels to rotate at the same speed.
— 2WD Indicator Light — If Equipped
This light alerts the driver that the vehicle is in the
two-wheel drive mode.
Green Indicator Lights
— Park/Headlight On Indicator Light
This indicator will illuminate when the park lights or
headlights are turned on.
— Front Fog Indicator Light — If Equipped
This indicator will illuminate when the front fog lights are
on.
— Turn Signal Indicator Lights
When the left or right turn signal is activated, the turn
signal indicator will flash independently and the corre-
sponding exterior turn signal lamps will flash. Turn signals
can be activated when the multifunction lever is moved
down (left) or up (right).
NOTE:
•A continuous chime will sound if the vehicle is driven
more than 1 mile (1.6 km) with either turn signal on.
• Check for an inoperative outside light bulb if either
indicator flashes at a rapid rate.
158 GETTING TO KNOW YOUR INSTRUMENT PANEL
WARNING!(Continued)
•The capabilities of an ABS equipped vehicle must
never be exploited in a reckless or dangerous manner
that could jeopardize the user ’s safety or the safety of
others.
ABS is designed to function with the OEM tires. Modifica-
tion may result in degraded ABS performance.
Anti-Lock Brake Warning Light
The yellow “Anti-Lock Brake Warning Light” will turn on
when the ignition is turned to the ON/RUN mode and
may stay on for as long as four seconds.
If the “Anti-Lock Brake Warning Light” remains on or
comes on while driving, it indicates that the anti-lock
portion of the brake system is not functioning and that
service is required. However, the conventional brake sys-
tem will continue to operate normally if the “Brake System
Warning Light” is not on.
If the “Anti-Lock Brake Warning Light” is on, the brake
system should be serviced as soon as possible to restore the
benefits of anti-lock brakes. If the “Anti-Lock Brake Warning
Light” does not come on when the ignition is turned to the
ON/RUN mode, have the light repaired as soon as possible.
Electronic Brake Control System
Your vehicle is equipped with an advanced Electronic
Brake Control system (EBC). This system includes Elec-
tronic Brake Force Distribution (EBD), Anti-Lock Brake
System (ABS), Brake Assist System (BAS), Hill Start Assist
(HSA), Traction Control System (TCS), Electronic Stability
Control (ESC), and Electronic Roll Mitigation (ERM). These
systems work together to enhance both vehicle stability
and control in various driving conditions.
Your vehicle may also be equipped with Trailer Sway
Control (TSC) and Hill Descent Control (HDC).
Electronic Brake Force Distribution (EBD)
This function manages the distribution of the braking
torque between the front and rear axles by limiting braking
pressure to the rear axle. This is done to prevent overslip of
the rear wheels to avoid vehicle instability, and to prevent
the rear axle from entering ABS before the front axle.
Brake System Warning Light
The red “Brake System Warning Light” will turn on when
the ignition is turned to the ON/RUN mode and may stay
on for as long as four seconds.
5
SAFETY 165
controls the wheel spin across a driven axle. If one wheel
on a driven axle is spinning faster than the other, the
system will apply the brake of the spinning wheel. This
will allow more engine torque to be applied to the wheel
that is not spinning. BLD may remain enabled even if TCS
and ESC are in a reduced mode.
Electronic Stability Control (ESC)
This system enhances directional control and stability of
the vehicle under various driving conditions. ESC corrects
for oversteering or understeering of the vehicle by apply-
ing the brake of the appropriate wheel(s) to assist in
counteracting the oversteer or understeer condition. En-
gine power may also be reduced to help the vehicle
maintain the desired path.
ESC uses sensors in the vehicle to determine the vehicle
path intended by the driver and compares it to the actual
path of the vehicle. When the actual path does not match
the intended path, ESC applies the brake of the appropriate
wheel to assist in counteracting the oversteer or understeer
condition.
•Oversteer — when the vehicle is turning more than
appropriate for the steering wheel position. •
Understeer — when the vehicle is turning less than
appropriate for the steering wheel position.
The “ESC Activation/Malfunction Indicator Light” located
in the instrument cluster will start to flash as soon as the
ESC system becomes active. The “ESC Activation/
Malfunction Indicator Light” also flashes when the TCS is
active. If the “ESC Activation/Malfunction Indicator
Light” begins to flash during acceleration, ease up on the
accelerator and apply as little throttle as possible. Be sure to
adapt your speed and driving to the prevailing road
conditions.
WARNING!
• Electronic Stability Control (ESC) cannot prevent the
natural laws of physics from acting on the vehicle,
nor can it increase the traction afforded by prevailing
road conditions. ESC cannot prevent accidents, in-
cluding those resulting from excessive speed in
turns, driving on very slippery surfaces, or hydro-
planing. ESC also cannot prevent accidents resulting
from loss of vehicle control due to inappropriate
driver input for the conditions. Only a safe, attentive,
(Continued)
5
SAFETY 169
WARNING!
•When in “Partial Off” mode, the TCS functionality
of ESC, (except for the limited slip feature described
in the TCS section), has been disabled and the “ESC
Off Indicator Light” will be illuminated. When in
“Partial Off” mode, the engine power reduction
feature of TCS is disabled, and the enhanced vehicle
stability offered by the ESC system is reduced.
• Trailer Sway control (TSC) is disabled when the ESC
system is in the “Partial Off” mode.
Full Off — If Equipped
This mode is intended for off-highway or off-road use only
and should not be used on any public roadways. In this
mode, TCS and ESC features are turned OFF. To enter the
“Full Off” mode, push and hold the “ESC Off” switch for
five seconds while the vehicle is stopped with the engine
running. After five seconds, a chime will sound, the “ESC
Off Indicator Light” will illuminate, and the “ESC OFF”
message will display in the instrument cluster. To turn ESC
ON again, momentarily push the “ESC Off” switch. NOTE:
System may switch from ESC “Full Off” to “Partial
Off” mode when vehicle exceeds a predetermined speed.
When the vehicle speed slows below the predetermined
speed the system will return to ESC “Full Off”.
ESC modes may also be affected by drive modes if so
equipped.
WARNING!
• In the ESC “Full Off” mode, the engine torque
reduction and stability features are disabled. There-
fore, enhanced vehicle stability offered by the ESC
system is unavailable. In an emergency evasive ma-
neuver, the ESC system will not engage to assist in
maintaining stability. ESC “Full Off” mode is in-
tended for off-highway or off-road use only.
• With the ESC switched off, the enhanced vehicle
stability offered by ESC is unavailable. In an emer-
gency evasive maneuver, the ESC system will not
engage to assist in maintaining stability. ESC “Full
Off” mode is only intended for off-highway or
off-road use.
• The Electronic Stability Control (ESC) cannot pre-
vent the natural laws of physics from acting on the
(Continued)
5
SAFETY 171
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 “In Case Of Emergency” 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.
252 STARTING AND OPERATING
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 tempera-
ture as well as vehicle speed. This feature improves warm
up time of the engine and transmission to achieve maxi-
mum 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 sec-
tion).
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 be-
low), 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
accelerate under heavily loaded conditions may be re-
duced. 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 ab-
normal 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 damag-
ing 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.
6
STARTING AND OPERATING 253
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
will automatically downshift (for engine braking) when the
throttle is closed and/or during steady braking maneu-
vers.The “TOW/HAUL Indicator Light” will illuminate in the
instrument cluster to indicate that TOW/HAUL mode has
been activated. Pushing 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 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 brak-
ing 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 possibly result-
ing 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 automatically
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.
TOW/HAUL Switch
256 STARTING AND OPERATING
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 converter 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 Over-
drive.
• If the vehicle has not been driven for several days, the
first few seconds of operation after shifting the transmis-
sion 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 converter
will refill within five seconds after starting the engine.
FOUR-WHEEL DRIVE OPERATION — IF EQUIPPED
Four-wheel drive trucks are equipped with either a manu-
ally shifted transfer case or an electronically shifted trans-
fer case. Refer to the operating instructions for your
transfer case, located in this section for further information.
Manually Shifted Transfer Case — If Equipped
The transfer case provides four mode positions:
• Two-Wheel Drive High Range (2H)
• Four-Wheel Drive Lock High Range (4H)
• Neutral (N)
• Four-Wheel Drive Low Range (4L)
For additional information on the appropriate use of each
transfer case mode position, see the information below:
2H
Two-Wheel Drive High Range — This range is for normal
street and highway driving on dry, hard surfaced roads.
4H
Four-Wheel Drive Lock 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 both 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 information.
6
STARTING AND OPERATING 257