2004 GMC SIERRA DENALI tow

Flash-to-Pass
This feature lets you use your high-beam headlamps to
signal a driver in front of you that you want to pass.
It works even if your headlamps are in the automatic
position.
To use it, pull the turn signal lever toward you, then
release it.
If your headlamps are in the automatic position or on
low beam, your high-beam headlamps will turn on.
They'll stay on as long as you hold the lever toward you.
The high-beam indicator on the instrument panel
cluster will come on. Release the lever to return to
normal operation.
Windshield Wipers
You control the windshield wipers by turning the band
with the wiper symbol on it.
8(Mist):For a single wiping cycle, turn the band to
mist. Hold it there until the wipers start. Then let go. The
wipers will stop after one wipe. If you want more
wipes, hold the band on mist longer.
N(Delay):You can set the wiper speed for a long or
short delay between wipes. This can be very useful
in light rain or snow. Turn the band to choose the delay
time. The closer to the top of the lever, the shorter
the delay.
6(Low Speed):For steady wiping at low speed,
turn the band away from you to the ®rst solid band past
the delay settings. For high-speed wiping, turn the
band further, to the second solid band past the delay
settings. To stop the wipers, move the band to off.
1(High Speed):For high-speed wiping, turn
the band further, to the second solid band past the
delay settings.
9(Off):To stop the wipers, move the band to off.
Be sure to clear ice and snow from the wiper blades
before using them. If they're frozen to the windshield,
carefully loosen or thaw them. If your blades do become
worn or damaged, get new blades or blade inserts.
3-7

Exterior Lamps
The control on the driver's side of the instrument panel
operates the exterior lamps.
Turn the control clockwise to operate the lamps.The exterior lamp control has four positions:
9(OFF):Turning the control to this position turns off
the Daytime Running Lamps (DRL), and the automatic
headlamps.
AUTO (Automatic):Turning the control to this position
puts the system into automatic headlamp mode.
;(Parking Lamps):Turning the control to this
position turns on the parking lamps, together with the
following:
·Sidemarker Lamps
·Taillamps
·License Plate Lamps
·Instrument Panel Lights
·Roof Marker Lamps (If Equipped)
5(Headlamps):Turning the control to this position
turns on the headlamps, together with the previously
listed lamps and lights.
You can switch your headlamps from high to low-beam
by pushing the turn signal/multifunction lever towards
the instrument panel.
3-12

Outlet Adjustment
Use the air outlets located
in the center and on the
side of your instrument
panel to direct the air¯ow.
Your vehicle has air outlets that allow you to adjust the
direction and amount of air¯ow inside the vehicle.
Move the louvers up or down. Use the thumbwheel next
to or underneath the outlet to close the louvers. For
the most efficient air¯ow and temperature control, keep
the outlet in the fully opened position.
Rear seat outlets can be used to adjust air¯ow toward
either seating area, the ¯oor or upward. Move the center
louvers up or down to direct the air¯ow.
Operation Tips
·
Keep the hood and front air inlets free of ice, snow,
or any other obstruction (such as leaves). The
heater and defroster will work far better, reducing
the chance of fogging the inside of your windows.
·Keep the air path under the front seats clear
of objects. This helps air to circulate throughout your
vehicle.
·Adding outside equipment to the front of your
vehicle, such as hood-air de¯ectors, etc., may affect
the performance of the heating and air conditioning
system. Check with your dealer before adding
equipment to the outside of your vehicle.
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Brake System Warning Light
With the ignition on, the brake system warning light
will ¯ash when you set the parking brake. The light will
¯ash if the parking brake doesn't release fully. If you
try to drive with the parking brake engaged, a chime
will sound when the vehicle speed is greater
than 3 mph (5 km/h).
Your vehicle's hydraulic brake system is divided into
two parts. If one part isn't working, the other part can still
work and stop you. For good braking, though, you
need both parts working well.
If the warning light comes on and a chime sounds there
could be a brake problem. Have your brake system
inspected right away.This light should come on brie¯y when you turn the
ignition key to RUN. If it doesn't come on then, have it
®xed so it will be ready to warn you if there's a
problem.
If the light comes on while you are driving, pull off the
road and stop carefully. You may notice that the pedal is
harder to push. Or, the pedal may go closer to the
¯oor. It may take longer to stop. If the light is still on,
have the vehicle towed for service. See
Towing
Your Vehicle on page 4-48.
{CAUTION:
Your brake system may not be working
properly if the brake system warning light is
on. Driving with the brake system warning light
on can lead to an accident. If the light is still
on after you have pulled off the road and
stopped carefully, have the vehicle towed for
service.
United States
Canada
3-37

Notice:If you drive your vehicle with the
transmission temperature gage above normal
operating range, you can damage the transmission.
This could lead to costly repairs that would not
be covered by your warranty. Do not drive your
vehicle while the transmission temperature gage
reading is above normal. See your dealer for service.
The following situations can cause the transmission to
operate at higher temperatures:
·Towing a trailer
·Hot outside air temperatures
·Hauling a large or heavy load
·Low transmission ¯uid level
·High transmission ¯uid level
·Restricted air ¯ow to the radiator and the auxiliary
transmission oil cooler (if equipped).
A temporary solution to hotter transmission operating
temperatures may be to let the transmission cool down.
If the transmission is operated at higher temperatures
on a frequent basis, see
Scheduled Maintenance
on page 6-4for the proper transmission maintenance
intervals.
Malfunction Indicator Lamp
Check Engine Light
Your vehicle is equipped
with a computer which
monitors operation of the
fuel, ignition and emission
control systems.
This system is called OBD II (On-Board
Diagnostics-Second Generation) and is intended to
assure that emissions are at acceptable levels for the
life of the vehicle, helping to produce a cleaner
environment. The Check Engine light comes on to
indicate that there is a problem and service is required.
Malfunctions often will be indicated by the system
before any problem is apparent. This may prevent more
serious damage to your vehicle. This system is also
designed to assist your service technician in correctly
diagnosing any malfunction.
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Notice:If you keep driving your vehicle with this
light on, after a while, your emission controls
may not work as well, your fuel economy may not
be as good and your engine may not run as
smoothly. This could lead to costly repairs that may
not be covered by your warranty.
Notice:Modi®cations made to the engine,
transmission, exhaust, intake or fuel system of your
vehicle or the replacement of the original tires
with other than those of the same Tire Performance
Criteria (TPC) can affect your vehicle's emission
controls and may cause this light to come on.
Modi®cations to these systems could lead to costly
repairs not covered by your warranty. This may
also result in a failure to pass a required Emission
Inspection/Maintenance test.
This light should come on, as a check to show you it is
working, when the ignition is on and the engine is
not running. If the light does not come on, have it
repaired. This light will also come on during a
malfunction in one of two ways:
·Light FlashingÐ A mis®re condition has been
detected. A mis®re increases vehicle emissions
and may damage the emission control system on
your vehicle. Diagnosis and service may be
required.
·Light On SteadyÐ An emission control system
malfunction has been detected on your vehicle.
Diagnosis and service may be required.
If the Light is Flashing
The following may prevent more serious damage to
your vehicle:
·Reducing vehicle speed.
·Avoiding hard accelerations.
·Avoiding steep uphill grades.
·If you are towing a trailer, reduce the amount of
cargo being hauled as soon as it is possible.
If the light stops ¯ashing and remains on steady, see ªIf
the Light Is On Steadyº following.
If the light continues to ¯ash, when it is safe to do so,
stop the vehicle.Find a safe place to park your vehicle.
Turn the key off, wait at least 10 seconds and restart
the engine. If the light remains on steady, see ªIf
the Light Is On Steadyº following. If the light is still
¯ashing, follow the previous steps, and see your dealer
for service as soon as possible.
3-41

Cruise Control Light
The cruise light comes on
whenever you set your
cruise control. See ªCruise
Controlº under
Turn
Signal/Multifunction Lever
on page 3-5
.
Tow/Haul Mode Light
This light is displayed
when the Tow/Haul mode
has been activated.
For more information, see
Towing a Trailer on
page 4-58.
3-44

SERVICE BRAKE SYSTEM
If there is a problem with the brake system, this
message will be displayed on the DIC. If this message
appears, stop as soon as possible and turn off the
vehicle. Restart the vehicle and check for the message
on the DIC display. If the message is still displayed,
or appears again when you begin driving, the brake
system needs service.
SERVICE BRAKE BOOSTER
If your vehicle has vacuum assist power brakes, this
message will be displayed on the DIC when there is a
problem with the Supplemental Brake Assist system.
If the message is displayed immediately after starting
the vehicle or the message appears while driving,
your Supplemental Brake Assist system needs service.
See
Brake System Warning Light on page 3-37.
{CAUTION:
Your brake system may not be working
properly if the SERVICE BRAKE BOOSTER
message is displayed.
If the brake system warning light is also on,
you should have the vehicle towed for service.
See ªBrake System Warning Lightº in the
Index.
If the brake system warning light isn't on, you
still have brakes, but the supplemental brake
assist system may not operate properly. In the
event of a vacuum loss, you may not have
vacuum power assist for braking. The brake
pedal will be harder to push and it will take
longer to stop. If you continue to drive with
this message displayed it can lead to a crash.
Have the brake system serviced as soon as
possible.
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