
1. lock the door from the
inside by sliding the
manual lock lever
rearward. To unlock
the door, slide the
manual lock lever
forward.
Power Door Locks
If your vehicle is equipped
with power door locks,
press the raised side of the
switch, with the lock
symbol, on either front
door to lock all the doors
at once.
Press the recessed side of the switch with the unlock
symbol, to unlock all the doors at once.The power door locks will operate at any time even
when the ignition is off.
Operating the power locks may interact with the
theft-deterrent system (if equipped). SeeContent
Theft-Deterrent on page 2-13.
Programmable Automatic
Door Locks
Your vehicle is equipped with an automatic lock/unlock
feature which enables you to program your vehicle’s
power door locks. You can program this feature through
the Driver Information Center (DIC), or by the following
method.
Programmable Locking Feature
The following is the list of available programming
options:
Mode 1:All doors lock when the transmission is shifted
into gear. This is the mode that is pre-programmed in
the factory for your vehicle.
Mode 2:All doors lock when the vehicle speed is
greater than 8 mph (13 km/h).
Mode 3:No automatic door locking.
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2003 - Sierra Denali

{CAUTION:
Shifting into a drive gear while your engine is
“racing”(running at high speed) is dangerous.
Unless your foot isfirmly on the brake pedal,
your vehicle could move very rapidly. You
could lose control and hit people or objects.
Don’t shift into a drive gear while your engine
is racing.
Notice:Damage to your transmission caused by
shifting out of PARK (P) or NEUTRAL (N) with
the engine racing isn’t covered by your warranty.
DRIVE (D):This position is for normal driving. If
you need more power for passing, and you’re:
Going less than about 35 mph (55 km/h), push your
accelerator pedal about halfway down.
Going about 35 mph (55 km/h) or more, push the
accelerator all the way down.
You’ll shift down to the next gear and have more power.
DRIVE (D) can be used when towing a trailer, carrying
a heavy load, driving on steep hills or for off-road driving.
You may want to shift the transmission to THIRD (3)
or, if necessary, a lower gear selection if the
transmission shifts too often.THIRD (3):This position is also used for normal driving,
however it offers more power and lower fuel economy
than DRIVE (D).
SECOND (2):This position gives you more power but
lower fuel economy. You can use SECOND (2) on
hills. It can help control your speed as you go down
steep mountain roads, but then you would also want to
use your brakes occasionally.
If you manually select SECOND (2), the transmission
will drive in second gear. You may use this feature
for reducing the speed of the rear wheels when you are
trying to start your vehicle from a stop on slippery
road surfaces.
FIRST (1):This position gives you even more power
(but lower fuel economy) than SECOND (2). You
can use it on very steep hills, or in deep snow or mud.
If the shift lever is put in FIRST (1) while the vehicle
is moving forward, the transmission won’t shift into rst
gear until the vehicle is going slowly enough.
Notice:If your wheels won’t turn, don’t try to drive.
This might happen if you were stuck in very deep
sand or mud or were up against a solid object. You
could damage your transmission. Also, if you
stop when going uphill, don’t hold your vehicle there
with only the accelerator pedal. This could overheat
and damage the transmission. Use your brakes
or shift into PARK (P) to hold your vehicle in
position on a hill.
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2003 - Sierra Denali

Lamps On Reminder
A reminder chime will sound when your headlamps or
parking lamps are manually turned on and your ignition is
off, in LOCK, ACCESSORY, or your door is open.
To disable the chime, turn the light off, then back on.
Daytime Running Lamps
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
first sold in Canada.
The DRL system will come on when the following
conditions are met:
•The ignition is on,
•the exterior lamp control is in AUTO
•the automatic transmission is not in PARK (P), and
•the light sensor determines it is daytime.When the DRL are on, only your DRL lamps will be on.
The taillamps, sidemarker and other lamps won’tbe
on. The instrument panel won’t be lit up either.
When it begins to get dark, the automatic headlamp
system will switch from DRL to the headlamps or the last
chosen headlamp setting that was used.
When you turn the exterior lamp control to off, the
headlamps will go off, and your DRL lamps will
illuminate, provided it is not dark outside.
Shifting the transmission into PARK (P) will allow you to
idle the vehicle with the DRL off. The DRL will stay
off until you release the parking brake or shift the
transmission out of PARK (P).
Puddle Lamps
Your vehicle is equipped with puddle lamps to help you
see the area near the base of the front doors when it
is dark out. The puddle lamps will illuminate when a door
is opened or when you press the UNLOCK button on
the keyless entry transmitter.
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2003 - Sierra Denali

Parking on Hills
{CAUTION:
You really should not park your vehicle, with a
trailer attached, on a hill. If something goes
wrong, your rig could start to move. People
can be injured, and both your vehicle and the
trailer can be damaged.
But if you ever have to park your rig on a hill, here’s
how to do it:
1. Apply your regular brakes, but don’t shift into
PARK (P) yet.
2. Have someone place chocks under the trailer
wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply your
parking brake and shift into PARK (P).
5. Release the regular brakes.
When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
start your engine,
shift into a gear, and
release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the
chocks.
Maintenance When Trailer Towing
Your vehicle will need service more often when you’re
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmission uid (don’t over ll),
engine oil, axle lubricant, belt, cooling system and
brake system. Each of these is covered in this manual,
and the Index will help you nd them quickly. If
you’re trailering, it’s a good idea to review these sections
before you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
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