2008 GMC SIERRA engine

Using this Manual
Many people read the owner manual from beginning to
end when they rst receive their new vehicle. If this
is done, it can help you learn about the features
and controls for the vehicle. Pictures and words work
together in the owner manual to explain things.
If your vehicle has the DURAMAX
®Diesel engine, refer
to the DURAMAX®Diesel supplement for additional
and specic information on this engine.
Index
A good place to quickly locate information about the
vehicle is the Index in the back of the manual. It is an
alphabetical list of what is in the manual and the
page number where it can be found.
Safety Warnings and Symbols
There are a number of safety cautions in this book. A
box with the word CAUTION is used to tell about things
that could hurt you or others if you were to ignore the
warning.
{CAUTION:
These mean there is something that could hurt
you or other people.
We tell you what the hazard is and what to do to help
avoid or reduce the hazard. Please read these cautions.
If you do not, you or others could be hurt.
A circle with a slash
through it is a safety
symbol which means “Do
Not,” “Do Not do this”
or “Do Not let this happen.”
iii

Keys...............................................................2-3
Remote Keyless Entry (RKE) System................2-4
Remote Keyless Entry (RKE) System
Operation...................................................2-5
Remote Vehicle Start......................................2-7
Doors and Locks............................................2-10
Door Locks..................................................2-10
Power Door Locks........................................2-10
Delayed Locking...........................................2-10
Programmable Automatic Door Locks..............2-11
Rear Door Security Locks..............................2-11
Lockout Protection........................................2-12
Rear Doors..................................................2-13
Tailgate.......................................................2-14
Windows........................................................2-15
Manual Windows..........................................2-16
Power Windows............................................2-16
Power Sliding Rear Window...........................2-17
Sun Visors...................................................2-18
Theft-Deterrent Systems..................................2-18
Content Theft-Deterrent.................................2-18
PASS-Key
®III+............................................2-20
PASS-Key®III+ Operation..............................2-20
Starting and Operating Your Vehicle................2-22
New Vehicle Break-In....................................2-22
Ignition Positions..........................................2-22Retained Accessory Power (RAP)...................2-23
Starting the Engine.......................................2-24
Fast Idle System..........................................2-25
Adjustable Throttle and Brake Pedal................2-26
Engine Coolant Heater..................................2-26
Active Fuel Management™.............................2-27
Automatic Transmission Operation...................2-28
Tow/Haul Mode............................................2-34
Four-Wheel Drive..........................................2-36
Parking Brake..............................................2-49
Shifting Into PARK (P)...................................2-50
Shifting Out of PARK (P)...............................2-52
Parking Over Things That Burn.......................2-53
Engine Exhaust............................................2-53
Running the Engine While Parked...................2-54
Mirrors...........................................................2-55
Manual Rearview Mirror.................................2-55
Automatic Dimming Rearview Mirror with
OnStar
®, Compass and Temperature
Display....................................................2-55
Automatic Dimming Rearview Mirror with
Compass and Temperature Display..............2-57
Outside Manual Mirrors..................................2-58
Outside Trailer-Tow Mirrors............................2-59
Outside Power Mirrors...................................2-59
Outside Power Foldaway Mirrors.....................2-61
Section 2 Features and Controls
2-1

Remote Keyless Entry (RKE)
System Operation
The vehicle’s doors can be locked and unlocked from
about 3 feet (1 m) up to 65 feet (20 m) away with
the Remote Keyless Entry (RKE) transmitter.
If your vehicle has the remote start feature you can also
start your vehicle with the RKE transmitter. The RKE
transmitter, with the remote start button, provides
an increased operating range of 195 feet (60 m) away.
However, the operating range may be less while the
vehicle is running. As a result, you may need to
be closer to your vehicle to turn it off than you were to
start it.
There are other conditions which can affect the
performance of the transmitter. SeeRemote Keyless
Entry (RKE) System on page 2-4.
/(Remote Vehicle Start):If your vehicle has this
feature, press
/to start the engine from outside the
vehicle using the RKE transmitter. SeeRemote
Vehicle Start on page 2-7for additional information.
Q(Lock):PressQto lock all the doors.
If enabled through the Driver Information Center (DIC),
the turn signal lamps will ash once to indicate
locking has occurred. If enabled through the DIC, the
horn will chirp when
Qis pressed again within
three seconds of the previous press of the lock button.With Remote Start
(Without Remote Start
Similar)
2-5

Battery Replacement
Replace the battery if the REPLACE BATTERY IN
REMOTE KEY message displays in the DIC. See
“REPLACE BATTERY IN REMOTE KEY” underDIC
Warnings and Messages on page 3-63for additional
information.
Notice:When replacing the battery, use care not to
touch any of the circuitry. Static from your body
transferred to these surfaces may damage the
transmitter.To replace the battery in the RKE transmitter:
1. Separate the halves of the transmitter with a at,
thin object inserted into the notch on the side.
2. Remove the old battery. Do not use a metal object.
3. Insert the new battery, positive side facing down.
Replace with a CR2032 or equivalent battery.
4. Put the transmitter back together tightly.
Remote Vehicle Start
Your vehicle may have a remote starting feature. This
feature allows you to start the engine from outside of the
vehicle. It may also start up the vehicle’s heating or
air conditioning systems and rear window defogger.
Normal operation of the system will return after the key
is turned to the ON/RUN position.
If your vehicle has an automatic climate control system,
the climate control system will default to a heating or
cooling mode depending on the outside temperatures. If
your vehicle does not have an automatic climate control
system, the system will turn on at the setting the vehicle
was set to when the vehicle was last turned off.
2-7

During a remote start, if your vehicle has an automatic
climate control system and heated seats, the heated
seats will turn on during colder outside temperatures and
will shut off when the key is turned to ON/RUN. If
your vehicle does not have an automatic climate control
system, during remote start, you will need to manually
turn the heated seats on and off. SeeHeated Seats
on page 1-6for additional information.
Laws in some communities may restrict the use of
remote starters. For example, some laws may require a
person using the remote start to have the vehicle in
view when doing so. Check local regulations for
any requirements on remote starting of vehicles.
Do not use the remote start feature if your vehicle is low
on fuel. Your vehicle may run out of fuel.
The RKE transmitter with the remote start button,
provides an increased range of operation. However, the
range may be less while the vehicle is running. As a
result, you may need to be closer to your vehicle to turn
it off, than you were to turn it on.
There are other conditions which can affect the
performance of the transmitter, seeRemote Keyless
Entry (RKE) System on page 2-4for additional
information./(Remote Start):This button will be on the RKE
transmitter if you have remote start.
To start the vehicle using the remote start feature:
1. Aim the transmitter at the vehicle.
2. Press and release the transmitter’s lock button. The
vehicle’s doors will lock. Immediately press and
hold the transmitter’s remote start button until the
turn signal lights ash. If you cannot see the
vehicle’s lights, press and hold the remote start
button for two to four seconds. Pressing the remote
start button again after the vehicle has started
will turn the engine off.
When the vehicle starts, the parking lamps will turn
on and remain on while the vehicle is running.
If the vehicle is left running it will automatically shut
off after 10 minutes unless a time extension has
been done.
3. If it is the rst remote start since the vehicle has
been driven, repeat these steps, while the engine
is still running, to extend the engine running time by
10 minutes. Remote start can be extended
one time.
After entering the vehicle during a remote start, insert
and turn the key to RUN to drive the vehicle.
2-8

To manually shut off a remote start, do any of the
following:
Aim the RKE transmitter at the vehicle and press
the remote start button until the parking lamps
turn off.
Turn on the hazard warning ashers.
Turn the ignition switch on and then off.
The vehicle can be remote started two separate times
between driving sequences. The engine will run for
10 minutes after each remote start.
Or, you can extend the engine run time by another
10 minutes within the rst 10 minute remote start time
frame, and before the engine stops.
For example, if the lock button and then the remote
start buttons are pressed again after the vehicle
has been running for ve minutes, 10 minutes are
added, allowing the engine to run for 15 minutes.
The additional ten minutes are considered a second
remote vehicle start.
Once two remote starts, or a single remote start with
one time extension has been done, the vehicle must be
started with the key.
After the key is removed from the ignition, the vehicle
can be remote started again.The vehicle cannot be remote started if the key is in the
ignition, the hood is not closed, or if there is an
emission control system malfunction and the check
engine light comes on.
Also, the engine will turn off during a remote vehicle
start if the coolant temperature gets too high or if the oil
pressure gets low.
Vehicles that have the remote vehicle start feature are
shipped from the factory with the remote vehicle
start system enabled. The system may be enabled or
disabled through the DIC. See “REMOTE START” under
DIC Vehicle Customization (With DIC Buttons) on
page 3-72for additional information. If your vehicle does
not have DIC buttons, see your dealer/retailer to
enable or disable the remote vehicle start system.
Remote Start Ready
If your vehicle does not have the remote vehicle start
feature, it may have the remote start ready feature. This
feature allows your dealer/retailer to add the
manufacturer’s remote vehicle start feature.
If your vehicle has the remote start ready feature, the
RKE transmitter will have an extended range that allows
locking or unlocking of the vehicle from approximately
197 feet (60 m) away.
See your dealer/retailer if you would like to add the
manufacturer’s remote vehicle start feature to your
vehicle.
2-9

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
Your vehicle has PASS-Key®III+ (Personalized
Automotive Security System) theft-deterrent system.
PASS-Key
®III+ is 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, ACC/ACCESSORY or START
from the LOCK/OFF position.
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.
When the PASS-Key
®III+ system senses that someone
is using the wrong key, it prevents the vehicle from
starting. Anyone using a trial-and-error method to start
the vehicle will be discouraged because of the high
number of electrical key codes.
If the engine does not start and the security light on the
instrument panel cluster comes on when trying to
start the vehicle, there may be a problem with your
theft-deterrent system. Turn the ignition off and try again.
2-20

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 5-123. 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
PASS-Key
®III+ to have a new key made. In an
emergency, contact Roadside Assistance.
It is possible for the PASS-Key
®III+ 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. If all the currently programmed keys are lost or
do not operate, you must see your dealer/retailer
or a locksmith who can service PASS-Key
®III+ to have
keys made and programmed to the system.
See your dealer/retailer or a locksmith who can service
PASS-Key
®III+ to get a new key blank that is cut
exactly as the ignition key that operates the system.To program the new additional key:
1. Verify that the new key has a
1stamped on it.
2. Insert the original, already programmed, 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 new key to be programmed and turn it to
the ON/RUN position within ve seconds of turning
the ignition to the LOCK/OFF position in Step 3.
The security light will turn off once the key has been
programmed.
5. Repeat Steps 1 through 4 if additional keys are to
be programmed.
If you lose or damage your PASS-Key
®III+ key, see
your dealer/retailer or a locksmith who can service
PASS-Key
®III+ to have a new key made.
Do not leave the key or device that disarms or
deactivates the theft deterrent system in the vehicle.
2-21