2008 GMC SIERRA Owner's Manual

The rainsensor will automatically control the frequency of
the wipes from the off setting to the high speed setting
according to the weather conditions. The wipers can be
left in a rainsense mode even when it is not raining.
When Rainsense™ is active, the headlamps will turn on
automatically if the exterior lamp control is in the
AUTO position and the wipers are active.
Notice:Going through an automatic car wash with
the wipers on can damage them. Turn the wipers
off when going through an automatic car wash.
Windshield Washer
{CAUTION:
In freezing weather, do not use your washer
until the windshield is warmed. Otherwise the
washer uid can form ice on the windshield,
blocking your vision.
L(Washer Fluid):Push the paddle marked with the
windshield washer symbol at the top of the multifunction
lever, to spray washer uid on the windshield. The
wipers clear the window and then either stop or return
to the preset speed.
Heated Windshield Washer
For vehicles with the heated windshield washer uid
system it can be used to help clear ice, snow, tree sap,
or bugs from your windshield.
The button is located in
the switchbank under the
climate controls.
Push the heated washer uid button to activate the
heated windshield washer uid system. The indicator
light will ash. This activation initiates four heated
wash/wipe cycles. The rst heated wash/wipe cycle may
take up to 40 seconds to occur, depending on outside
temperature. After the rst wash/wipe cycle, it may take
up to 20 seconds for each of the remaining cycles to
begin. Press the button again to turn off the heated
windshield washer uid system or it will automatically
turn off after four wipe cycles have been completed.
When the heated windshield washer uid system
is activated under certain outside temperature
conditions, steam may ow out of the washer nozzles
for a short period of time before washer uid is sprayed.
This is a normal condition.
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Cruise Control
{CAUTION:
Cruise control can be dangerous where you
cannot drive safely at a steady speed. So, do
not use your cruise control on winding roads
or in heavy traffic.
Cruise control can be dangerous on slippery
roads. On such roads, fast changes in tire
traction can cause excessive wheel slip, and
you could lose control. Do not use cruise
control on slippery roads.
With cruise control, you can maintain a speed of about
25 mph (40 km/h) or more without keeping your foot
on the accelerator. This can really help on long
trips. Cruise control does not work at speeds below
about 25 mph (40 km/h).
When you apply your brakes, cruise control is turned off.
If your vehicle has an Allison
®automatic transmission,
see “Grade Braking and Cruise Grade Braking
(Allison Transmission
®) underTow/Haul Mode onpage 2-34for an explanation of how cruise control
interacts with the Range Selection Mode, tow/haul and
grade braking systems.
If your vehicle has the StabiliTrak
®™ system and
begins to limit wheel spin while you are using cruise
control, the cruise control will automatically disengage.
SeeStabiliTrak
®System on page 4-6. When road
conditions allow you to safely use it again, you may turn
the cruise control back on.
The cruise control buttons
are located on left side of
the steering wheel.
T(On/Off):This button can both activate and turn
off the system. The indicator light is on when cruise
control is on and turns off when cruise control is off.
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+ RES (Resume/Accelerate):Press this button to
make the vehicle accelerate or resume to a previously
set speed.
SET−(Set/Coast):Press this button to set the speed
or make the vehicle decelerate.
[(Cancel):Press this button to cancel cruise control
without erasing the set speed from memory.
Setting Cruise Control
Cruise control will not work if the parking brake is set, or
if the master cylinder brake uid level is low.
The cruise control light on the instrument panel cluster
will come on after the cruise control has been set to
the desired speed.
{CAUTION:
If you leave your cruise control on when you
are not using cruise, you might hit a button
and go into cruise when you do not want to.
You could be startled and even lose control.
Keep the cruise control switch off until you
want to use cruise control.
1. Press the cruise control On/Off button.
2. Get up to the desired speed.
3. Press the SET−button located on the steering
wheel and release it.
4. Take your foot off the accelerator.
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Resuming a Set Speed
If you apply the brakes while the cruise control is set,
the cruise control is disengaged. But it does not need to
be reset.
Once the vehicle speed reaches about 25 mph
(40 km/h) or more, press the +RES button on the
steering wheel. The vehicle will go back to the previous
set speed and stay there.
Increasing Speed While Using Cruise
Control
To increase the cruise speed while using cruise control:
Press and hold the +RES button on the steering
wheel until you reach your new desired speed,
then release it.
To increase vehicle speed in small increments,
press the +RES button. Each time this is done,
the vehicle will go about 1 mph (1.6 km/h) faster.
Reducing Speed While Using Cruise
Control
To reduce the vehicle speed while using cruise control:
Press and hold the SET– button on the steering
wheel until the desired lower speed is reached,
then release it.
To slow down in very small amounts, press the
SET– button on the steering wheel briey. Each
time this is done, the vehicle will go about 1 mph
(1.6 km/h) slower.
Passing Another Vehicle While Using
Cruise Control
Use the accelerator pedal to increase the vehicle speed.
When you take your foot off the pedal, the vehicle will
slow down to the previous set cruise speed.
Using Cruise Control on Hills
How well the cruise control will work on hills depends
upon the vehicle speed, load, and the steepness of the
hills. While going up steep hills, you might have to
step on the accelerator pedal to maintain the vehicle’s
speed. While going downhill, you might have to brake or
shift to a lower gear to keep the vehicle’s speed
down. Of course, applying the brake turns off the cruise
control. Many drivers nd this to be too much trouble
and do not use cruise control on steep hills.
Ending Cruise Control
There are three ways to end cruise control:
Step lightly on the brake pedal.
Press the cancel button on the steering wheel.
Press the On/Off button on the steering wheel.
3-16

Erasing Speed Memory
When the cruise control or the ignition is turned off, the
cruise control set speed memory is erased.
Exterior Lamps
The exterior lamps control
is located on the
instrument panel to the left
of the steering wheel.
It controls the following systems:
Headlamps
Taillamps
Parking Lamps
License Plate Lamps
Instrument Panel LightsThe exterior lamps control has four positions:
O(Off):Turn the control to this position to turn off the
automatic headlamps and daytime running lamps
(DRL). Turn the headlamp control to the off position
again to turn the automatic headlamps or DRL back on.
For vehicles rst sold in Canada, the off position will
only work when the vehicle is shifted into PARK (P).
AUTO (Automatic):Turn the control to this position to
automatically turn on the headlamps at normal
brightness, together with the following:
Parking Lamps
Instrument Panel Lights
Taillamps
License Plate Lamps
When the vehicle is turned off and the headlamps are in
AUTO, the headlamps may automatically remain on
for a set time. The time of the delay can be changed
using the DIC. SeeDriver Information Center (DIC) on
page 3-54.
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;(Parking Lamps):Turn the control to this position
to turn on the parking lamps together with the
following:
Instrument Panel Lights
Taillamps
License Plate Lamps
2(Headlamps):Turn the control to this position to
turn on the headlamps together with the following:
Parking Lamps
Instrument Panel Lights
Taillamps
License Plate Lamps
When the headlamps are turned on while the vehicle is
on, the headlamps turn off automatically 10 minutes
after the ignition is turned off. When the headlamps are
turned on while the vehicle is off, the headlamps will
stay on for 10 minutes before automatically turning off to
prevent the battery from being drained. Turn the
headlamp control to off and then back to the headlamp
on position to make the headlamps stay on for an
additional 10 minutes.
Push the turn signal/multifunction lever toward the
instrument panel to change the headlamps from low
beam to high beam.
Headlamps on Reminder
A reminder chime will sound when the headlamps or
parking lamps are manually turned on and your ignition
is off and a door is open. To disable the chime, turn
the light off.
Daytime Running Lamps (DRL)
Daytime Running Lamps (DRL) can make it easier for
others to see the front of your vehicle during the
day. DRL can be helpful in many different driving
conditions, but they can be especially helpful in the short
periods after dawn and before sunset. Fully functional
daytime running lamps are required on all vehicles
rst sold in Canada.
The DRL system will come on when the following
conditions are met:
The ignition is on.
The exterior lamps control is in AUTO.
The transmission is not in PARK (P).
The light sensor determines it is daytime.
When the DRL are on, only the DRL lamps will be on.
The taillamps, sidemarker, and other lamps will not
be on. The instrument panel will not be lit up either.
3-18

When it begins to get dark, the automatic headlamp
system will switch from DRL to the headlamps.
To turn off the DRL lamps, turn the exterior lamps
control to the OFF position and then release. For
vehicles rst sold in Canada, the transmission must be
in the PARK (P) position, before the DRL lamps can
be turned off.
Automatic Headlamp System
When it is dark enough outside, the automatic headlamp
system will turn on the headlamps at the normal
brightness, along with the taillamps, sidemarker, parking
lamps, and the instrument panel lights. The radio
lights will also be dim.
To turn off the automatic headlamp system, turn the
exterior lamps switch to the off position and then release
it. For vehicles rst sold in Canada, the transmission
must be in the PARK (P) position, before the automatic
headlamp system can be turned off.
The vehicle has a light sensor located on the top of the
instrument panel in the defroster grille that regulates
when the automatic headlamps turn on. Be sure it is not
covered, or the headlamps will come on whenever
the ignition is on.
The system may also turn on the headlamps when
driving through a parking garage, heavy overcast
weather, or a tunnel. This is normal.There is a delay in the transition between the daytime
and nighttime operation of the Daytime Running
Lamps (DRL) and the automatic headlamp systems so
that driving under bridges or bright overhead street
lights does not affect the system. The DRL and
automatic headlamp system will only be affected when
the light sensor detects a change in lighting lasting
longer than the delay.
If the vehicle is started in a dark garage, the automatic
headlamp system will come on immediately. Once
the vehicle leaves the garage, it takes approximately
one minute for the automatic headlamp system to
change to DRL if it is bright enough outside. During that
delay, the instrument panel cluster may not be as
bright as usual. Make sure the instrument panel
brightness control is in the full bright position. See
Instrument Panel Brightness on page 3-21.
To idle the vehicle with the automatic headlamp system
off, turn the control to the off position.
The headlamps will also stay on after you exit the
vehicle. This feature can be programmed using the
Driver Information Center (DIC). SeeDIC Vehicle
Customization (With DIC Buttons) on page 3-72.
The regular headlamp system can be turned on
when needed.
3-19

Puddle Lamps
If your vehicle has puddle lamps, they come on when
the unlock button on the Remote Keyless Entry
(RKE) Transmitter is pressed. The lamps time out or
turn off once the engine is started.
Fog Lamps
-(Fog Lamps):If your vehicle has fog lamps, the
control is located next to the exterior lamps control
on the instrument panel, to the left of the steering
column.
The ignition must be in the ON/RUN position for the fog
lamps to come on.
Press the button to turn the fog lamps on or off. A light
will come on in the instrument panel cluster.
When the fog lamps are turned on, the parking lamps
automatically turn on.
When the headlamps are changed to high-beam, the
fog lamps also go off. When the high-beam headlamps
are turned off, the fog lamps will come on again.
Some localities have laws that require the headlamps to
be on along with the fog lamps.
Auxiliary Roof Mounted Lamp
If your vehicle has this feature, this button includes
wiring provisions for a dealer or a qualied service
center to install an auxiliary roof lamp.
This button is located on
the overhead console.
When the wiring is connected to an auxiliary roof
mounted lamp, pressing the bottom of the button will
activate the lamp and illuminate an indicator light at the
bottom of this button. Pressing the top of the button
will turn off the roof mounted lamp and indicator.
The emergency roof lamp circuit is fused at 30 amps,
so the total current draw of the attached lamps
should be less than this value. The attachment points
for the roof lamp circuits are two blunt cut wires located
above the overhead console, a dark green switched
power wire and a black ground wire.
For further information on roof mount emergency lamp
installation, please visit the GM Uptter website at
www.gmuptters.com or contact your dealer.
3-20