2009 GMC ENVOY DENALI trailer

Starting and Operating Your
Vehicle
New Vehicle Break-In
Notice:The vehicle does not need an elaborate
break-in. But it will perform better in the long run if
you follow these guidelines:
Keep your speed at 55 mph (88 km/h) or less for
the rst 500 miles (805 km).
Do not drive at any one constant speed, fast or
slow, for the rst 500 miles (805 km). Do not
make full-throttle starts. Avoid downshifting to
brake or slow the vehicle.
Avoid making hard stops for the rst 200 miles
(322 km) or so. During this time the new brake
linings are not yet broken in. Hard stops
with new linings can mean premature wear and
earlier replacement. Follow this breaking-in
guideline every time you get new brake linings.
Do not tow a trailer during break-in. SeeTowing
a Trailer on page 4-46for the trailer towing
capabilities of the vehicle and more information.
Following break-in, engine speed and load can
be gradually increased.
2-20

P (Park):This position locks the rear wheels. It is the
best position to use when you start the engine because
the vehicle cannot move easily.
{CAUTION:
It is dangerous to get out of the vehicle if the shift
lever is not fully in P (Park) with the parking brake
rmly set. The vehicle can roll.
Do not leave the vehicle when the engine is
running unless you have to. If you have left the
engine running, the vehicle can move suddenly.
You or others could be injured. To be sure the
vehicle will not move, even when you are on fairly
level ground, always set the parking brake and
move the shift lever to P (Park). SeeShifting Into
Park on page 2-34. If you are pulling a trailer, see
Towing a Trailer on page 4-46.
{CAUTION:
If you have four-wheel drive, the vehicle will be free
to roll — even if the shift lever is in P (Park) — if the
transfer case is in Neutral. So, be sure the transfer
case is in a drive gear — not in Neutral. See
Four-Wheel Drive on page 2-28. SeeShifting Into
Park on page 2-34.
Make sure the shift lever is fully in P (Park) before
starting the engine. The vehicle has an automatic
transmission shift lock control system. You have to fully
apply the brake pedal, then press the shift lever
button before you can shift from P (Park) when the
ignition key is in ON/RUN. If you cannot shift out
of P (Park), ease pressure on the shift lever and push
the shift lever all the way into P (Park) as you maintain
brake application. Then press the shift lever button
and move the shift lever into another gear. SeeShifting
Out of Park on page 2-36.
2-26

R (Reverse):Use this gear to back up.
Notice:Shifting to R (Reverse) while the vehicle is
moving forward could damage the transmission.
The repairs would not be covered by the vehicle
warranty. Shift to R (Reverse) only after the vehicle
is stopped.
To rock the vehicle back and forth to get out of snow,
ice, or sand without damaging the transmission,
seeIf Your Vehicle is Stuck in Sand, Mud, Ice, or Snow
on page 4-30.
N (Neutral):In this position, the engine does not
connect with the wheels. To restart the engine when the
vehicle is already moving, use N (Neutral) only.
{CAUTION:
Shifting into a drive gear while the engine is
running at high speed is dangerous. Unless your
foot is rmly on the brake pedal, the vehicle could
move very rapidly. You could lose control and hit
people or objects. Do not shift into a drive gear
while the engine is running at high speed.Notice:Shifting out of P (Park) or N (Neutral) with
the engine running at high speed may damage
the transmission. The repairs would not be covered
by the vehicle warranty. Be sure the engine is
not running at high speed when shifting the vehicle.
D (Drive):This position is for normal driving. It provides
the best fuel economy. If you need more power for
passing, and you are:
Going less than about 35 mph (55 km/h), push the
accelerator pedal about halfway down.
Going about 35 mph (55 km/h) or more, push the
accelerator all the way down.
The vehicle will shift down to the next gear and have
more power.
Downshifting the transmission in slippery road conditions
could result in skidding, see “Skidding” underLoss of
Control on page 4-12.
D (Drive) 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 3 (Third) or, if
necessary, a lower gear selection if the transmission
shifts too often.
3 (Third):This position is also used for normal driving. It
reduces vehicle speed more than D (Drive) without using
the brakes. You might choose 3 (Third) instead of
D (Drive) when driving on hilly, winding roads, when
towing a trailer, so there is less shifting between gears
and when going down a steep hill.
2-27

Parking Brake
To set the parking brake,
hold the regular brake
pedal down with your foot
and pull up on the parking
brake lever located
between the seats.
To release the parking brake, hold the regular brake
pedal down. Pull the parking brake lever up until you can
press in the button at the end of the lever. Hold the
button in as you move the parking brake lever all the
way down.If the ignition is on, the brake system warning light on
the instrument panel cluster will come on. SeeBrake
System Warning Light on page 3-35.
Notice:Driving with the parking brake on can
overheat the brake system and cause premature
wear or damage to brake system parts. Verify that
the parking brake is fully released and the brake
warning light is off before driving.
If you are towing a trailer and you must park on a hill,
seeTowing a Trailer on page 4-46.
2-33

Shifting Into Park
{CAUTION:
It can be dangerous to get out of the vehicle if the
shift lever is not fully in P (Park) with the parking
brake rmly set. The vehicle can roll. If you have
left the engine running, the vehicle can move
suddenly. You or others could be injured. To be
sure the vehicle will not move, even when you are
on fairly level ground, use the steps that follow.
With four-wheel drive, the vehicle will be free to
roll — even if the shift lever is in P (Park) — if your
transfer case is in Neutral. So, be sure the transfer
case is in a drive gear — not in Neutral. See
Four-Wheel Drive on page 2-28. Always put the
shift lever fully in P (Park) with the parking brake
rmly set. If you are pulling a trailer, seeTowing a
Trailer on page 4-46.To shift into P (Park):
1. Hold the brake pedal down with your foot and set
the parking brake.
2. Move the shift lever into P (Park) by pressing the
button on the side of the shift lever and pushing
the lever all the way toward the front of the vehicle.
3. Turn the ignition key to OFF/LOCK.
4. Remove the key and take it with you. You know the
vehicle is in P (Park) if the key can be removed
from the ignition.
2-34

Running the Vehicle While Parked
It is better not to park with the engine running. But if you
ever have to, here are some things to know.
{CAUTION:
Idling a vehicle in an enclosed area with poor
ventilation is dangerous. Engine exhaust may
enter the vehicle. Engine exhaust contains Carbon
Monoxide (CO) which cannot be seen or smelled.
It can cause unconsciousness and even death.
Never run the engine in an enclosed area that has
no fresh air ventilation. For more information, see
Engine Exhaust on page 2-37.
{CAUTION:
It can be dangerous to get out of the vehicle if the
automatic transmission shift lever is not fully in
P (Park) with the parking brake rmly set. The
CAUTION: (Continued)
CAUTION: (Continued)
vehicle can roll. Do not leave the vehicle when the
engine is running unless you have to. If you have
left the engine running, the vehicle can move
suddenly. You or others could be injured. To be
sure the vehicle will not move, even when you are
on fairly level ground, always set the parking
brake and move the shift lever to P (Park).
{CAUTION:
If the vehicle has four-wheel drive, it will be free to
roll — even if the shift lever is in P (Park) — if the
transfer case is in N (Neutral). So be sure the
transfer case is in a drive gear — not in N (Neutral).
SeeFour-Wheel Drive on page 2-28.
Follow the proper steps to be sure the vehicle will not
move. SeeShifting Into Park on page 2-34.
If pulling a trailer, seeTowing a Trailer on page 4-46.
2-38

If the vehicle has a trailer towing option with added
wiring for the trailer lamps, a turn signal asher is used.
With this asher installed, the signal indicator ashes
even if a turn signal bulb is burned out. Check the front
and rear turn signal lamps regularly to make sure
they are working.
Turn Signal On Chime
A chime sounds if the turn signal has been on 3/4 of a
mile (1.2 km). Move the turn signal lever to off.
Headlamp High/Low-Beam Changer
To change the headlamps from low to high beam,
push the lever toward the instrument panel. To return to
low-beam headlamps, pull the multifunction lever
toward you. Then release it.
When the high beams are
on, this indicator light on
the instrument panel
cluster will also be on.
Flash-to-Pass
This feature lets high-beam headlamps be used to
signal to a driver in front of you that you want to pass.
It works even if the headlamps are in the automatic
position.
To use it, pull the turn signal lever toward you, then
release it.
If the headlamps are in the automatic position or on low
beam, the high-beam headlamps turn on. They will stay
on as long as the lever is held toward you. The high-beam
indicator on the instrument panel cluster comes on.
Release the lever to return to normal operation.
Windshield Wipers
8(Mist):Turn the band to mist, for a single wiping
cycle. Hold it there until the wipers start, then release it.
The wipers will stop after one wipe. Hold the band on
mist longer if more wipe cycles are needed.
9(Off):Turns the wipers off.
N(Windshield Wipers):Turn the band to control the
windshield wipers.
6: Turn the band to set the wiper speed for a long or
short delay between wipes. The closer to the top of the
lever, the shorter the delay time.
3-8

Exit Lighting
With exit lighting, the interior lamps come on when you
remove the key from the ignition. If the dome override
is off, these lamps stay on for a short period of time and
then go out.
Reading Lamps
The reading lamps are located in the front console.
Press the lens on the lamps to turn the reading lamps
on or off.
Electric Power Management
The vehicle has Electric Power Management (EPM)
that estimates the battery’s temperature and state
of charge. It then adjusts the voltage for best
performance and extended life of the battery.
When the battery’s state of charge is low, the voltage
is raised slightly to quickly bring the charge back
up. When the state of charge is high, the voltage is
lowered slightly to prevent overcharging. If the vehicle
has a voltmeter gage or a voltage display on the
Driver Information Center (DIC), you may see the
voltage move up or down. This is normal. If there is a
problem, an alert will be displayed.The battery can be discharged at idle if the electrical
loads are very high. This is true for all vehicles.
This is because the generator (alternator) may not be
spinning fast enough at idle to produce all the power that
is needed for very high electrical loads.
A high electrical load occurs when several of the
following are on, such as: headlamps, high beams,
fog lamps, rear window defogger, climate control fan at
high speed, heated seats, engine cooling fans, trailer
loads, and loads plugged into accessory power outlets.
EPM works to prevent excessive discharge of the
battery. It does this by balancing the generator’s output
and the vehicle’s electrical needs. It can increase
engine idle speed to generate more power, whenever
needed. It can temporarily reduce the power demands of
some accessories.
Normally, these actions occur in steps or levels, without
being noticeable. In rare cases at the highest levels
of corrective action, this action may be noticeable to
the driver. If so, a Driver Information Center (DIC)
message might be displayed, such as BATTERY
SAVER ACTIVE, BATTERY VOLTAGE LOW, or
LOW BATTERY. If this message is displayed, it is
recommended that the driver reduce the electrical loads
as much as possible. SeeDIC Warnings and Messages
on page 3-51.
3-17