ignition GMC SIERRA 2008 Manual Online

6. Release the parking brake only after the vehicle
being towed is rmly attached to the tow vehicle.
7. Turn the ignition to LOCK/OFF.
Towing a Trailer
If your vehicle has a diesel engine, see the DURAMAX®
Diesel manual for more information.
Do not tow a trailer during break-in. SeeNew Vehicle
Break-In on page 2-22for more information.
{CAUTION:
If you do not use the correct equipment and
drive properly, you can lose control when you
pull a trailer. For example, if the trailer is too
heavy, the brakes may not work well — or even
at all. You and your passengers could be
seriously injured. Pull a trailer only if you have
followed all the steps in this section. Ask your
dealer for advice and information about towing
a trailer with your vehicle.Notice:Pulling a trailer improperly can damage
your vehicle and result in costly repairs not covered
by your warranty. To pull a trailer correctly, follow
the advice in this part, and see your dealer for
important information about towing a trailer with
your vehicle.
To identify the trailering capacity of your vehicle, you
should read the information in “Weight of the Trailer” that
appears later in this section.
Trailering is different than just driving your vehicle by
itself. Trailering means changes in acceleration, braking,
handling, durability and fuel economy. Successful,
safe trailering takes correct equipment, and it has to be
used properly.
That’s the reason for this part. In it are many time-tested,
important trailering tips and safety rules. Many of
these are important for your safety and that of your
passengers. So please read this section carefully before
you pull a trailer.
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Integrated Trailer Brake Control
System
Your vehicle may have an
Integrated Trailer Brake
Control (ITBC) system for
electric trailer brakes.
This symbol is located on the Trailer Brake Control
Panel on vehicles with an Integrated Trailer Brake
Control System. The power output to the trailer brakes
is based on the amount of brake pressure being
applied by your vehicle’s brake system. This available
power output to the trailer brakes can be adjusted
to a wide range of trailering situations.The ITBC system is integrated with your vehicle’s brake,
anti-lock brake and StabiliTrak
®(if equipped) systems.
In trailering conditions that cause your vehicle’s anti-lock
brake or StabiliTrak
®systems to activate, power sent
to the trailer’s brakes will be automatically adjusted
to minimize trailer wheel lock-up. This does not imply
that your trailer has the StabiliTrak
®system.
If your vehicle’s brake, anti-lock brake or StabiliTrak
®
systems are not functioning properly, your ITBC system
may not be fully functional or may not function at all.
Make sure all of these systems are fully operational to
ensure full functionality of the ITBC system.
The ITBC system is powered through your vehicle’s
electrical system. Turning the ignition off will also turn off
the ITBC system. The ITBC system is fully functional
only when the ignition is in ON or in RUN.
The ITBC system can only be used with trailers with
electric brakes.
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6. Adjust the Trailer Gain to just below the point of
trailer wheel lock-up, indicated by trailer wheel
squeal or puffs of tire smoke when a trailer
wheel locks.
Trailer wheel lock-up may not occur if towing a
heavily loaded trailer. In this case, adjust the Trailer
Gain to the highest allowable setting for the
towing condition.
7. Re-adjust Trailer Gain any time vehicle loading,
trailer loading or road surface conditions change
or if you notice trailer wheel lock-up at any
time while you are towing
Other ITBC Related DIC Messages
In addition to displaying TRAILER GAIN and TRAILER
OUTPUT through the DIC, trailer connection and
ITBC system status is displayed in the DIC.
TRAILER CONNECTED – This message will be briey
displayed when a trailer with electric brakes is rst
connected to the vehicle. This message will
automatically turn off in about ten seconds. The driver
can also acknowledge this message before it
automatically turns off.CHECK TRAILER WIRING – This message will be
displayed if:
1. The ITBC system rst determines connection to a
trailer with electric brakes and then the trailer
harness becomes disconnected from the vehicle.
If the disconnect occurs while the vehicle is
stationary, this message will automatically turn off in
about thirty seconds. This message will also turn
off if the driver acknowledges this message off or if
the trailer harness is re-connected.
If the disconnect occurs while the vehicle is moving,
this message will continue until the ignition is
turned off. This message will also turn off if the
driver acknowledges this message off or if the trailer
harness is re-connected.
2. There is an electrical fault in the wiring to the
electric trailer brakes. This message will continue as
long as there is an electrical fault in the trailer
wiring. This message will also turn off if the driver
acknowledges this message off.
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To determine if the electrical fault is on the vehicle side
or trailer side of the trailer wiring harness connection,
do the following:
1. Disconnect the trailer wiring harness from the
vehicle.
2. Turn the ignition OFF.
3. Wait ten seconds, then turn the ignition back
to RUN.
4. If the CHECK TRAILER WIRING message
re-appears, the electrical fault is on the vehicle side.
If the CHECK TRAILER WIRING message only
re-appears when you connect the trailer wiring
harness to the vehicle, the electrical fault is on the
trailer side.
SERVICE TRAILER BRAKE SYSTEM – This message
will be displayed when there is a problem with the
ITBC system. If this message persists over multiple
ignition cycles there is problem with the ITBC system.
Take your vehicle to an authorized GM dealer to
have the ITBC system diagnosed and repaired.If either the CHECK TRAILER WIRING or SERVICE
TRAILER BRAKE SYSTEM message is displayed while
you are driving your vehicle, you no longer have
power available to your trailer brakes. When traffic
conditions allow, carefully pull your vehicle over to the
side of the road and turn the ignition off. Check the
wiring connection to the trailer and turn the ignition back
on. If either of these messages continues, either your
vehicle or your trailer needs service.
An authorized GM dealer may be able to diagnose and
repair problems with your trailer. However, any
diagnosis and repair of your trailer is not covered under
your GM Warranty. Please contact your trailer dealer
for assistance with trailer repairs and trailer warranty
information.
4-85

Adding Washer Fluid
Your vehicle has a low washer uid message in the DIC
that comes on when the washer uid is low. The
message is displayed for 15 seconds at the start of
each ignition cycle. When the WASHER FLUID LOW
ADD FLUID message displays, you will need to add
washer uid to the windshield washer uid reservoir.
Open the cap with the
washer symbol on it. Add
washer uid until the tank
is full. SeeEngine
Compartment Overview on
page 5-14for reservoir
location.Notice:
When using concentrated washer uid,
follow the manufacturer’s instructions for
adding water.
Do not mix water with ready-to-use washer uid.
Water can cause the solution to freeze and
damage your washer uid tank and other parts of
the washer system. Also, water does not clean as
well as washer uid.
Fill the washer uid tank only three-quarters full
when it is very cold. This allows for uid
expansion if freezing occurs, which could
damage the tank if it is completely full.
Do not use engine coolant (antifreeze) in your
windshield washer. It can damage the vehicle’s
windshield washer system and paint.
5-41

3. Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles are not touching
each other. If they are, it could cause an unwanted
ground connection. You would not be able to start
your vehicle, and the bad grounding could damage
the electrical systems.
To avoid the possibility of the vehicles rolling, set
the parking brake rmly on both vehicles involved in
the jump start procedure. Put the automatic
transmission in PARK (P) or a manual transmission
in NEUTRAL before setting the parking brake.
If you have a four-wheel-drive vehicle, be sure the
transfer case is in a drive gear, not in NEUTRAL.
Notice:If you leave your radio or other accessories
on during the jump starting procedure, they could
be damaged. The repairs would not be covered
by your warranty. Always turn off your radio and
other accessories when jump starting your vehicle.
4. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or the accessory power outlets. Turn off the
radio and all the lamps that are not needed. This will
avoid sparks and help save both batteries. And it
could save the radio!5. Open the hood on the other vehicle and locate the
positive (+) and negative (−) terminal locations on
that vehicle.
The positive (+) terminal, is located under a red
plastic cover at the positive battery post. To uncover
the positive (+) terminal, open the red plastic cover.
The remote negative (−) terminal is a stud located
on the right front passenger side of the engine,
where the negative battery cable attaches.
SeeEngine Compartment Overview on page 5-14
5-47

Tire Pressure Monitor Operation
The Tire Pressure Monitor System (TPMS), if your
vehicle has this feature, is designed to warn the driver
when a low tire pressure condition exists. TPMS sensors
are mounted onto each tire and wheel assembly,
excluding the spare tire and wheel assembly. The TPMS
sensors monitor the air pressure in the vehicle’s tires
and transmits the tire pressure readings to a receiver
located in the vehicle.
When a low tire pressure
condition is detected, the
TPMS will illuminate the
low tire pressure warning
symbol located on the
instrument panel cluster.
At the same time a message to check the pressure in a
specic tire appears on the Driver Information Center
(DIC) display. The low tire pressure warning light and
the DIC warning message come on at each ignition cycle
until the tires are inated to the correct ination pressure.If your vehicle has DIC buttons, tire pressure levels can
be viewed by the driver. For additional information and
details about the DIC operation and displays seeDIC
Operation and Displays (With DIC Buttons) on page 3-55
orDIC Operation and Displays (Without DIC Buttons)
on page 3-60andDIC Warnings and Messages
on page 3-63.
The low tire pressure warning light may come on in cool
weather when the vehicle is rst started, and then turn
off as you start to drive. This could be an early indicator
that the air pressure in the tire(s) are getting low and
need to be inated to the proper pressure.
A Tire and Loading Information label, attached to your
vehicle, shows the size of your vehicle’s original
equipment tires and the correct ination pressure for
your vehicle’s tires when they are cold. SeeLoading
Your Vehicle on page 4-36, for an example of the Tire
and Loading Information label and its location on
your vehicle. Also seeInflation - Tire Pressure
on page 5-74.
Your vehicle’s TPMS can warn you about a low tire
pressure condition but it does not replace normal tire
maintenance. SeeTire Inspection and Rotation on
page 5-81andTires on page 5-66.
Notice:Liquid tire sealants could damage the Tire
Pressure Monitor System (TPMS) sensors. Sensor
damage caused by using a tire sealant is not
covered by your warranty. Do not use liquid tire
sealants.
5-78

TPMS Malfunction Light and Message
The TPMS will not function properly if one or more of the
TPMS sensors are missing or inoperable. When the
system detects a malfunction, the low tire warning light
ashes for about one minute and then stays on for the
remainder of the ignition cycle. A DIC warning message
is also displayed. The low tire warning light and DIC
warning message come on at each ignition cycle until the
problem is corrected. Some of the conditions that can
cause the malfunction light and DIC message to
come on are:
One of the road tires has been replaced with the
spare tire. The spare tire does not have a TPMS
sensor. The TPMS malfunction light and DIC
message should go off once you re-install the road
tire containing the TPMS sensor.
The TPMS sensor matching process was started but
not completed or not completed successfully after
rotating the vehicle’s tires. The DIC message and
TPMS malfunction light should go off once the TPMS
sensor matching process is performed successfully.
See “TPMS Sensor Matching Process” later in this
section.
One or more TPMS sensors are missing or
damaged. The DIC message and the TPMS
malfunction light should go off when the TPMS
sensors are installed and the sensor matching
process is performed successfully. See your
dealer/retailer for service.
Replacement tires or wheels do not match your
vehicle’s original equipment tires or wheels. Tires
and wheels other than those recommended for your
vehicle could prevent the TPMS from functioning
properly. SeeBuying New Tires on page 5-84.
Operating electronic devices or being near facilities
using radio wave frequencies similar to the TPMS
could cause the TPMS sensors to malfunction.
If the TPMS is not functioning it cannot detect or signal
a low tire condition. See your dealer/retailer for service if
the TPMS malfunction light and DIC message comes on
and stays on.
5-79

TPMS Sensor Matching Process
Each TPMS sensor has a unique identication code.
Any time you rotate your vehicle’s tires or replace one or
more of the TPMS sensors, the identication codes will
need to be matched to the new tire/wheel position. The
sensors are matched to the tire/wheel positions in the
following order: driver side front tire, passenger side front
tire, passenger side rear tire, and driver side rear tire
using a TPMS diagnostic tool. See your dealer/retailer
for service.
The TPMS sensors can also be matched to each
tire/wheel position by increasing or decreasing the tire’s
air pressure. If increasing the tire’s air pressure, do not
exceed the maximum ination pressure indicated on the
tire’s sidewall.
To decrease air-pressure out of a tire you can use the
pointed end of the valve cap, a pencil-style air pressure
gage, or a key.
You have two minutes to match the rst tire/wheel
position, and ve minutes overall to match all
four tire/wheel positions. If it takes longer than
two minutes, to match the rst tire and wheel, or more
than ve minutes to match all four tire and wheel
positions the matching process stops and you need to
start over.The TPMS sensor matching process is outlined below:
1. Set the parking brake.
2. Turn the ignition switch to ON/RUN with the
engine off.
3. Press the Remote Keyless Entry (RKE) transmitter’s
LOCK and UNLOCK buttons at the same time for
approximately ve seconds. The horn sounds twice
to signal the receiver is in relearn mode and TIRE
LEARNING ACTIVE message displays on the DIC
screen.
If your vehicle does not have RKE, press the Driver
Information Center (DIC) vehicle information
button until the PRESS
VTO RELEARN TIRE
POSITIONS message displays. The horn sounds
twice to signal the receiver is in relearn mode
and TIRE LEARNING ACTIVE message displays
on the DIC screen.
If your vehicle does not have RKE or DIC buttons,
press the trip odometer reset stem located on the
instrument panel cluster until the PRESS
VTO
RELEARN TIRE POSITIONS message displays.
The horn sounds twice to signal the receiver is in
relearn mode and TIRE LEARNING ACTIVE
message displays on the DIC screen.
5-80

4. Start with the driver side front tire.
5. Remove the valve cap from the valve cap stem.
Activate the TPMS sensor by increasing or
decreasing the tire’s air pressure for ve seconds,
or until a horn chirp sounds. The horn chirp,
which may take up to 30 seconds to sound,
conrms that the sensor identication code has
been matched to this tire and wheel position.
6. Proceed to the passenger side front tire, and repeat
the procedure in Step 5.
7. Proceed to the passenger side rear tire, and repeat
the procedure in Step 5.
8. Proceed to the driver side rear tire, and repeat the
procedure in Step 5. The horn sounds two times to
indicate the sensor identication code has been
matched to the driver side rear tire, and that the
TPMS sensor matching process is no longer active.
The TIRE LEARNING ACTIVE message on the DIC
display screen goes off.
9. Turn the ignition switch to LOCK/OFF.
10. Set all four tires to the recommended air pressure
level as indicated on the Tire and Loading
Information label.
11. Put the valve caps back on the valve stems.Tire Inspection and Rotation
We recommend that you regularly inspect your
vehicle’s tires, including the spare tire, for signs of
wear or damage. SeeWhen It Is Time for New
Tires on page 5-84for more information.
Tires should be rotated every 5,000 to 8,000 miles
(8 000 to 13 000 km). SeeScheduled Maintenance
(Gasoline Engine) on page 6-4.
The purpose of a regular tire rotation is to achieve
a uniform wear for all tires on the vehicle. This
will ensure that your vehicle continues to perform
most like it did when the tires were new.
Any time you notice unusual wear, rotate your
tires as soon as possible and check wheel
alignment. Also check for damaged tires or wheels.
SeeWhen It Is Time for New Tires on page 5-84
andWheel Replacement on page 5-88.
If your vehicle has dual rear wheels, also seeDual
Tire Operation on page 5-76.
5-81