GMC ENVOY DENALI 2008 Owners Manual

Testing the Alarm
To test the alarm:
1. From inside the vehicle, lower the driver’s window
and open the driver’s door.
2. Activate the system by locking the doors with the
power door lock switch while the door is open, or
with the RKE transmitter.
3. Get out of the vehicle, close the door and wait for
the security light to go out.
4. Then reach in through the window, unlock the door
with the manual door lock and open the door.
This should set off the alarm.
When the alarm is set the power door unlock switch will
not work.
If the alarm does not sound when it should but the
headlamps ash, check to see if the horn works.
The horn fuse may be blown. To replace the fuse,
seeFuses and Circuit Breakers on page 5-110.
If the alarm does not sound or the headlamps do
not ash, the vehicle should be serviced by your
dealer/retailer.
Passlock®(U. S. Only)
Your vehicle has the Passlock®theft-deterrent system.
Passlock®is a passive theft-deterrent system that
enables fuel if the ignition lock cylinder is turned with a
valid key. If a correct key is not used or the ignition lock
cylinder has been tampered with, the fuel system is
disabled and the vehicle will not start.
During normal operation, the security light will turn off
about ve seconds after the key is turned to ON/RUN.
If the engine stalls and the security light ashes,
wait about 10 minutes until the light stops ashing before
trying to restart the engine. Remember to release the
key from START as soon as the engine starts.
If the engine does not start after three tries, the vehicle
needs service.
If the engine is running and the security light comes on,
you will be able to restart the engine if you turn the engine
off. However, your Passlock
®system is not working
properly and must be serviced by your dealer/retailer.
Your vehicle is not protected by Passlock
®at this time.
You may also want to check the fuse. SeeFuses and
Circuit Breakers on page 5-110. See your dealer/retailer
for service.
In an emergency, call the Roadside Assistance Center.
SeeRoadside Assistance Program on page 7-8.
Do not leave the key or device that disarms or
deactivates the theft deterrent system in the vehicle.
2-17

PASS-Key®III+
The PASS-Key®III+ system operates on a radio
frequency subject to Federal Communications
Commission (FCC) Rules and with Industry Canada.
This device complies with Part 15 of the FCC Rules.
Operation is subject to the following two conditions:
1. This device may not cause harmful interference.
2. This device must accept any interference received,
including interference that may cause undesired
operation.
This device complies with RSS-210 of Industry Canada.
Operation is subject to the following two conditions:
1. This device may not cause interference.
2. This device must accept any interference received,
including interference that may cause undesired
operation of the device.
Changes or modications to this system by other than
an authorized service facility could void authorization to
use this equipment.
PASS-Key
®III+ uses a radio frequency transponder in
the key that matches a decoder in your vehicle.
PASS-Key®III+ Operation
(Canada Only)
Your vehicle has a passive theft-deterrent system.
The system is automatically armed when the key
is removed from the ignition.
The system is automatically disarmed when the key is
turned to ON/RUN.
You do not have to manually arm or disarm the system.
The security light will come on if there is a problem
with arming or disarming the theft-deterrent system.
The key uses a transponder that matches an immobilizer
control unit in your vehicle. Only the correct key will
start the vehicle. If the key is ever damaged, you may
not be able to start your vehicle.
2-18

When trying to start the vehicle, if the engine does not
start and the security light comes on, there may be
a problem with your theft-deterrent system. Turn
the ignition off and try again.
If the engine still does not start, and the key appears to
be undamaged, try another ignition key. At this time,
you may also want to check the fuse. SeeFuses
and Circuit Breakers on page 5-110. If the engine still
does not start with the other key, your vehicle needs
service. If your vehicle does start, the rst key may be
faulty. See your dealer/retailer who can service the
theft-deterrent system and have a new key made.
It is possible for the theft-deterrent system decoder to
learn the transponder value of a new or replacement
key. Up to 10 keys may be programmed for the vehicle.
The following procedure is for programming additional
keys only.Canadian Owners:If you lose or damage your keys,
only a dealer/retailer can service the theft-deterrent
system to have new keys made. To program additional
keys you will require two current driver’s keys.
To program a new key do the following:
1. Verify that the new key has PK3+ stamped on it.
2. Insert the current driver’s key in the ignition
and start the engine. If the engine will not start
see your dealer/retailer for service.
3. After the engine has started, turn the key to
LOCK/OFF, and remove the key.
4. Insert the second current driver’s key in the ignition
and start the engine within ten seconds of removing
the previous key. If the engine will not start see
your dealer/retailer for service.
2-19

5. After the engine has started, turn the key to
LOCK/OFF, and remove the key. Insert the key
to be programmed and turn it to ON within
ten seconds of removing the previous key.
The security light will turn off once the key has
been programmed.
6. Repeat the Steps 1 through 5 if additional keys are
to be programmed.
If the security light comes on and stays on while driving,
you will be able to restart the engine if you turn it off.
The theft-deterrent system, however, is not working
properly and must be serviced by your dealer/retailer.
Your vehicle is not protected by the theft-deterrent
system at this time.
In an emergency, contact Roadside Assistance.
SeeRoadside Assistance Program on page 7-8.
Do not leave the key or device that disarms or
deactivates the theft deterrent system in the vehicle.Starting and Operating Your
Vehicle
New Vehicle Break-In
Notice:Your 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 4-45for the trailer towing
capabilities of your vehicle and more
information.
Following break-in, engine speed and load can be
gradually increased.
2-20

Ignition Positions
Use the key to turn the
ignition switch to four
different positions.
Press the regular brake pedal, and turn the ignition
to ON/RUN to shift out of PARK (P).
Notice:Using a tool to force the key from the
ignition switch could cause damage or break the
key. Use the correct key and turn the key only
with your hand. Make sure the key is all the way in.
If none of this works, then your vehicle needs
service.A (LOCK/OFF):This position locks the ignition and
transmission. It is a theft-deterrent feature. You will only
be able to remove the key when the ignition is turned
to LOCK/OFF.
If the steering wheel is locked, move it from right to left
and turn the key to ACC/ACCESSORY. If none of
this works, then your vehicle needs service.
B (ACC/ACCESSORY):This position lets you use
things like the radio and the windshield wipers when
the engine is off.
Lengthy operation of features such as the radio in the
ACC/ACCESSORY may drain the battery and prevent
your vehicle from starting. Do not operate your vehicle
in the ACC/ACCESSORY for a long period of time.
C (ON/RUN):This is the position for driving.
The battery could be drained if you leave the key in
the ACC/ACCESSORY or ON/RUN position with the
engine off. You may not be able to start your vehicle if the
battery is allowed to drain for an extended period of time.
D (START):This position starts the engine.
2-21

Key In the Ignition
Never leave your vehicle with the keys inside. If you
leave the key in the ignition and park your vehicle, a
chime will sound, when you open the driver’s door.
Remember to remove your key from the ignition and take
it with you. This will lock your ignition and transmission.
Also, always remember to lock the doors.
The battery could be drained if you leave the key in the
ignition while your vehicle is parked. You may not be
able to start your vehicle after it has been parked for an
extended period of time.
Retained Accessory Power (RAP)
These vehicle accessories can be used for up to
20 minutes after the engine is turned off:
Audio System
Power Windows
Overhead Console
Sunroof (if equipped)These features will work when the key is in ON/RUN
or ACC/ACCESSORY. Once the key is turned from
ON/RUN to LOCK/OFF, these features continue to
work for up to 20 minutes, or until a door is opened.
Starting the Engine
Move your shift lever to PARK (P) or NEUTRAL (N).
Your engine will not start in any other position – this
is a safety feature. To restart when you are already
moving, use NEUTRAL (N) only.
Notice:Do not try to shift to PARK (P) if your
vehicle is moving. If you do, you could damage the
transmission. Shift to PARK (P) only when your
vehicle is stopped.
2-22

Starting Procedure
1. With your foot off the accelerator pedal, turn the
ignition key to START. When the engine starts,
let go of the key. The idle speed will go down as
your engine gets warm. Do not race the engine
immediately after starting it. Operate the engine
and transmission gently to allow the oil to warm
up and lubricate all moving parts.
Your vehicle has a Computer-Controlled Cranking
System. This feature assists in starting the engine
and protects components. If the ignition key is turned
to the START position, and then released when the
engine begins cranking, the engine will continue
cranking for a few seconds or until the vehicle starts.
If the engine does not start and the key is held in
START for many seconds, cranking will be stopped
after 15 seconds to prevent cranking motor damage.
To prevent gear damage, this system also prevents
cranking if the engine is already running. Engine
cranking can be stopped by turning the ignition
switch to the ACC/ACCESSORY or LOCK/OFF
position.
Notice:Cranking the engine for long periods of
time, by returning the key to the START position
immediately after cranking has ended, can overheat
and damage the cranking motor, and drain the
battery. Wait at least 15 seconds between each try,
to let the cranking motor cool down.2. If the engine does not start after 5-10 seconds,
especially in very cold weather (below 0°F or−18°C),
it could be ooded with too much gasoline. Try
pushing the accelerator pedal all the way to the oor
and holding it there as you hold the key in START
for up to a maximum of 15 seconds. Wait at least
15 seconds between each try, to allow the cranking
motor to cool down. When the engine starts, let go of
the key and accelerator. If the vehicle starts briey
but then stops again, do the same thing. This clears
the extra gasoline from the engine. Do not race the
engine immediately after starting it. Operate the
engine and transmission gently until the oil warms
up and lubricates all moving parts.
Notice:The engine is designed to work with the
electronics in your vehicle. If you add electrical
parts or accessories, you could change the way the
engine operates. Before adding electrical equipment,
check with your dealer/retailer. If you do not, your
engine might not perform properly. Any resulting
damage would not be covered by your vehicle’s
warranty.
2-23

Adjustable Throttle and Brake Pedal
If your vehicle has this feature, you can change the
position of the throttle and brake pedals. This feature is
designed for shorter drivers, since the pedals cannot
move farther away from the standard position, but can
move closer for better pedal reach.
The vehicle must be in PARK (P) for this feature to
operate.
The switch used to adjust
the pedals is located on
the steering column.
Press the switch forward or backward to move the
pedals closer or farther away from you.
Engine Coolant Heater
The engine coolant heater, if available, can help in cold
weather conditions at or below 0°F (−18°C) for easier
starting and better fuel economy during engine warm-up.
Plug in the coolant heater at least four hours before
starting your vehicle. An internal thermostat in the
plug-end of the cord may exist which will prevent
engine coolant heater operation at temperatures
above 0°F (−18°C).
To Use the Engine Coolant Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical cord.
The cord is located on the driver’s side of the
engine compartment next to the battery box
facing the engine.
3. Plug it into a normal, grounded 110-Volt AC outlet.
2-24

{CAUTION:
Plugging the cord into an ungrounded outlet
could cause an electrical shock. Also, the
wrong kind of extension cord could overheat
and cause a re. You could be seriously
injured. Plug the cord into a properly grounded
three-prong 110-volt AC outlet. If the cord will
not reach, use a heavy-duty three-prong
extension cord rated for at least 15 amps.
4. Before starting the engine, be sure to unplug and
store the cord as it was before to keep it away
from moving engine parts. If you do not, it could
be damaged.
How long should you keep the coolant heater plugged in?
The answer depends on the outside temperature, the
kind of oil you have, and some other things. Instead of
trying to list everything here, we ask that you contact your
dealer in the area where you will be parking your vehicle.
The dealer/retailer can give you the best advice for that
particular area.
Active Fuel Management™
Your vehicle’s V8 engine may have Active Fuel
Management™. This system allows the engine to
operate on either all or half of its cylinders, depending
on your driving conditions.
When less power is required, such as cruising at a
constant vehicle speed, the system will operate in the
half cylinder mode, allowing your vehicle to achieve
better fuel economy. When greater power demands are
required, such as accelerating from a stop, passing,
or merging onto a freeway, the system will maintain
full-cylinder operation.
2-25

Automatic Transmission Operation
There are several different
positions for your gear shift
lever.
PARK (P):This position locks the rear wheels. It is the
best position to use when you start the engine
because your vehicle cannot move easily.{CAUTION:
It is dangerous to get out of your vehicle if the
shift lever is not fully in PARK (P) with the
parking brake rmly set. Your vehicle can roll.
Do not leave your 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 your
vehicle will not move, even when you are on
fairly level ground, always set your parking
brake and move the shift lever to PARK (P).
SeeShifting Into PARK (P) on page 2-34.Ifyou
are pulling a trailer, seeTowing a Trailer on
page 4-45.
2-26