— 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.
4
GETTING TO KNOW YOUR INSTRUMENT PANEL 155
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 Warn-
ing 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.
5
SAFETY 161
6. Push the “ESC Off” button located in the lower switchbank below the climate control four times within 20
seconds. The “ESC Off Indicator Light” should turn on
and turn off two times.
7. Rotate the steering wheel back to center and then an additional slightly more than one-half turn to the right.
8. Turn the ignition to the OFF mode and then back to ON. If the sequence was completed properly, the “ESC Off
Indicator Light” will blink several times to confirm HSA
is disabled.
9. Repeat these steps if you want to return this feature to its previous setting.
Traction Control System (TCS)
This system monitors the amount of wheel spin of each of
the driven wheels. If wheel spin is detected, the TCS may
apply brake pressure to the spinning wheel(s) and/or
reduce engine power to provide enhanced acceleration and
stability. A feature of the TCS, Brake Limited Differential
(BLD), functions similar to a limited slip differential and
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.
5
SAFETY 165
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
vehicle, nor can it increase the traction afforded by
prevailing road conditions. ESC cannot prevent all
accidents, including those resulting from excessive
speed in turns, driving on very slippery surfaces, or
hydroplaning. ESC also cannot prevent collisions.
(Continued)
ESC Activation/Malfunction Indicator Light And
ESC OFF Indicator Light
The “ESC Activation/Malfunction Indicator
Light” in the instrument cluster will come on
when the ignition is turned to the ON mode. It
should go out with the engine running. If the
“ESC Activation/Malfunction Indicator Light” comes on
continuously with the engine running, a malfunction has
been detected in the ESC system. If this light remains on
after several ignition cycles, and the vehicle has been
driven several miles (kilometers) at speeds greater than
30 mph (48 km/h), see your authorized dealer as soon as
possible to have the problem diagnosed and corrected.
The “ESC Activation/Malfunction Indicator Light” (lo-
cated in the instrument cluster) starts to flash as soon as the
tires lose traction and the ESC system becomes active. The
“ESC Activation/Malfunction Indicator Light” also flashes
when 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.
168 SAFETY
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.
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 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 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
6
STARTING AND OPERATING 251
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
254 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 255
Electronically Shifted Transfer Case (Four-Position
Switch) — If Equipped
The electronic shift transfer case is operated by the 4WD
Control Switch (Transfer Case Switch), which is located on
the instrument panel.
This electronically shifted transfer case provides four mode
positions:
•Two-Wheel Drive High Range (2WD)
• Four-Wheel Drive Lock High Range (4WD LOCK)
• Four-Wheel Drive Low Range (4WD LOW) •
Neutral (NEUTRAL)
For additional information on the appropriate use of each
transfer case mode position, see the information below:
2WD
Rear Wheel Drive High Range — This range is for normal
street and highway driving on dry, hard surfaced roads.
4WD LOCK
Four-Wheel Drive Lock High Range — This range maxi-
mizes torque to the front driveshaft, forcing the front and
rear wheels to rotate at the same speed. This range pro-
vides additional traction for loose, slippery road surfaces
only.
4WD LOW
Four-Wheel Drive Low Range — This range provides low
speed four-wheel drive. It maximizes torque to the front
driveshaft, forcing the front and rear wheels to rotate at the
same speed. This range provides additional traction and
maximum pulling power for loose, slippery road surfaces
only. Do not exceed 25 mph (40 km/h).
NEUTRAL (N)
Neutral — This range disengages both the front and rear
driveshafts from the powertrain. To be used for flat towing
Four-Position/Part Time Transfer Case
6
STARTING AND OPERATING 259