2007 GMC SIERRA CLASSIC maintenance

CHANGE ENGINE OIL
This message is displayed when the engine oil
needs to be changed.
When you change the engine oil, be sure to reset
the CHANGE ENGINE OIL message. See
Engine Oil Life System (Gasoline Engine) on
page 489,Engine Oil (Gasoline Engine) on
page 486, andScheduled Maintenance (Gasoline
Engine) on page 617for more information.
CHARGING SYSTEM FAILURE
On some vehicles, if there is a problem with the
generator and battery charging system, this
message will appear on the DIC, a chime will
sound, and the battery warning light on the
instrument panel cluster will come on. Driving with
this problem could drain the battery. Turn off all
unnecessary accessories. Stop and turn off
the vehicle as soon as it is safe to do so. Have
the electrical system checked by your dealer
immediately. SeeBattery Warning Light on
page 253andVoltmeter Gage on page 253for
more information.
CHECK OIL LEVEL
If your vehicle has an oil level sensor, and the oil
level in the vehicle is low, this message will
appear on the DIC. Check the oil level and correct
it as necessary. You may need to let the vehicle
cool or warm up and cycle the ignition to be
sure this message will clear. Once the problem is
corrected, pressing any of the four DIC buttons
will acknowledge the message and clear it from the
DIC display. If your vehicle does not have the
four DIC buttons, pressing the trip odometer reset
stem will acknowledge the message and clear
it from the DIC display. SeeEngine Oil (Gasoline
Engine) on page 486for additional information.
CHECK WASHER FLUID
If the washer uid level is low, this message will
appear on the DIC. SeeWindshield Washer
Fluid on page 516. Adding washer uid to the
windshield washer reservoir will clear the
message. Pressing any of the four DIC buttons
will acknowledge the message and clear it from the
DIC display. If your vehicle does not have the
four DIC buttons, pressing the trip odometer reset
stem will acknowledge the message and clear
it from the DIC display.
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TRANSMISSION HOT
Notice:If you drive your vehicle while the
transmission uid is overheating and the
transmission temperature warning is displayed
on the instrument panel cluster and/or DIC,
you can damage the transmission. This could
lead to costly repairs that would not be
covered by your warranty. Do not drive your
vehicle with overheated transmission uid
or while the transmission temperature warning
is displayed.
If the transmission uid temperature becomes
high, this message will appear on the DIC display.
When the transmission enters the protection
mode, you may notice a change in the
transmission shifting patterns. When the
transmission uid temperature returns to normal,
the display will turn off and the transmission
shifting patterns will return to normal.If the vehicle has the Tow/Haul mode, use this
feature if the transmission is operating at higher
temperatures and/or the following situations
exist, which can cause the transmission to operate
at higher temperatures:
Towing a trailer
Hot outside air temperatures
Hauling a large or heavy load
Over-loading
Low transmission uid level
High transmission uid level
Restricted air ow to the radiator and the
auxiliary transmission oil cooler
A temporary solution to hotter transmission
operating temperatures may be to let the
transmission cool down. If the transmission is
operated at higher temperatures on a frequent
basis, seeScheduled Maintenance (Gasoline
Engine) on page 617for the transmission
your vehicle is equipped with for the proper
transmission maintenance intervals. Also see
Transmission Temperature Gage on page 257for
more information.
280

To reinstall the lower air dam, do the following:
1. Line up each
push-pin with its
intended retainer
and push the washer
portion of the
push-pin toward the
retainer until it
locks into place.
2. Push the at end of
the push-pin toward
the retainer until
it locks into place,
making sure each
is secure.Before You Go Off-Roading
There are some things to do before you go out.
For example, be sure to have all necessary
maintenance and service work done. Check to
make sure all underbody shields, if the vehicle has
them, are properly attached. Be sure you read
all the information about your four-wheel-drive
vehicle in this manual. Is there enough fuel? Is the
spare tire fully inated? Are the uid levels up
where they should be? What are the local
laws that apply to off-roading where you will be
driving? If you do not know, you should check with
law enforcement people in the area. Will you be
on someone’s private land? If so, be sure to
get the necessary permission.
375

After Off-Road Driving
Remove any brush or debris that has collected
on the underbody, chassis, or under the hood.
These accumulations can be a re hazard.
After operation in mud or sand, have the brake
linings cleaned and checked. These substances
can cause glazing and uneven braking. Check the
body structure, steering, suspension, wheels,
tires, and exhaust system for damage. Also, check
the fuel lines and cooling system for any leakage.
Your vehicle will require more frequent service
due to off-road use. Refer to the Maintenance
Schedule for additional information.
Driving at Night
Night driving is more dangerous than day driving.
One reason is that some drivers are likely to
be impaired — by alcohol or drugs, with night
vision problems, or by fatigue.
Here are some tips on night driving.
Drive defensively.
Do not drink and drive.
Adjust the inside rearview mirror to reduce the
glare from headlamps behind you.
Since you cannot see as well, you may need
to slow down and keep more space between
you and other vehicles.
Slow down, especially on higher speed roads.
Your vehicle’s headlamps can light up only so
much road ahead.
In remote areas, watch for animals.
If you are tired, pull off the road in a safe
place and rest.
No one can see as well at night as in the daytime.
But as we get older these differences increase.
A 50-year-old driver may require at least twice as
much light to see the same thing at night as a
20-year-old.
What you do in the daytime can also affect your
night vision. For example, if you spend the
day in bright sunshine you are wise to wear
sunglasses. Your eyes will have less trouble
adjusting to night. But if you are driving, do not
wear sunglasses at night. They may cut down on
glare from headlamps, but they also make a
lot of things invisible.
391

Maintenance When Trailer Towing
Your vehicle will need service more often when
you’re pulling a trailer. SeeScheduled
Maintenance (Gasoline Engine) on page 617for
more information. Things that are especially
important in trailer operation are automatic
transmission uid (don’t overll), 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.
Trailer Wiring Harness
Your vehicle is equipped with one of the following
wiring harnesses for towing a trailer or hauling
a slide-in camper.
Basic Trailer Wiring
All regular, extended cab and crew cab pickups
have an eight-wire trailer towing harness.For vehicles not equipped with heavy duty
trailering, the harness is clipped to the vehicle’s
frame behind the spare tire mount. The harness
requires the installation of a trailer connector,
which is available through your dealer.
If your trailer is equipped with electric brakes, you
can get a jumper harness (electric trailer brake
control) with a trailer battery feed fuse from
your dealer.
If you need to tow a light-duty trailer with a
standard four-way round pin connector, you can
also get an adapter from your dealer.
456

Washing Your Vehicle............................... 592
Cleaning Exterior Lamps/Lenses................ 593
Finish Care............................................... 593
Windshield and Wiper Blades.................... 594
Aluminum or Chrome-Plated Wheels......... 594
Tires......................................................... 595
Sheet Metal Damage................................. 595
Finish Damage.......................................... 596
Underbody Maintenance............................ 596
Chemical Paint Spotting............................ 596
Vehicle Care/Appearance Materials............ 597
Vehicle Identication.................................. 598
Vehicle Identication Number (VIN)........... 598
Service Parts Identication Label............... 598Electrical System........................................ 599
Add-On Electrical Equipment..................... 599
Windshield Wiper Fuses............................ 599
Power Windows and Other Power
Options.................................................. 599
Fuses and Circuit Breakers....................... 600
Instrument Panel Fuse Block..................... 600
Center Instrument Panel Fuse Block......... 602
Underhood Fuse Block.............................. 603
Capacities and Specications.................... 609
Section 5 Service and Appearance Care
467

California Proposition 65 Warning
Most motor vehicles, including this one, contain
and/or emit chemicals known to the State of
California to cause cancer and birth defects or other
reproductive harm. Engine exhaust, many parts and
systems (including some inside the vehicle), many
uids, and some component wear by-products
contain and/or emit these chemicals.
Doing Your Own Service Work
{CAUTION:
You can be injured and your vehicle could
be damaged if you try to do service work
on a vehicle without knowing enough
about it.
Be sure you have sufficient knowledge,
experience, the proper replacement
parts, and tools before you attempt any
vehicle maintenance task.
CAUTION: (Continued)
CAUTION: (Continued)

Be sure to use the proper nuts, bolts,
and other fasteners. English and
metric fasteners can be easily
confused. If you use the wrong
fasteners, parts can later break or fall
off. You could be hurt.
If you want to do some of your own service work,
you will want to use the proper service manual.
It tells you much more about how to service
your vehicle than this manual can. To order the
proper service manual, seeService Publications
Ordering Information on page 657.
Your vehicle has an airbag system. Before
attempting to do your own service work, see
Servicing Your Airbag-Equipped Vehicle on
page 108.
You should keep a record with all parts receipts
and list the mileage and the date of any service
work you perform. SeeMaintenance Record
on page 634.
469

Adding Equipment to the Outside
of Your Vehicle
Things you might add to the outside of your
vehicle can affect the airow around it. This may
cause wind noise and affect windshield washer
performance. Check with your dealer before
adding equipment to the outside of your vehicle.
Fuel
If your vehicle has a diesel engine, see “Diesel
Fuel Requirements and Fuel System” in the
DURAMAX
®Diesel Supplement.
For vehicles with gasoline engines, please
read this.
Gasoline
Use of the recommended fuel is an important part
of the proper maintenance of your vehicle. To
help keep your engine clean and maintain optimum
vehicle performance, GM recommends the use
of gasoline advertised as TOP TIER Detergent
Gasoline.The 8th digit of your Vehicle Identication Number
(VIN) shows the code letter or number that
identies your engine. You will nd the VIN at
the top left of the instrument panel. SeeVehicle
Identication Number (VIN) on page 598.
If your vehicle has the 5.3L V8 engine
(VIN Code Z), you may use either regular
unleaded gasoline or ethanol fuel containing
up to 85% ethanol (E85); also seeFuel E85
(85% Ethanol) on page 473. In all other gasoline
engines, use only regular unleaded gasoline.
Gasoline Octane
For all vehicles, except those with the 6.0L V8
engine (VIN Code N), use regular unleaded
gasoline with a posted octane rating of 87 or
higher. If the octane rating is less than 87,
you may notice an audible knocking noise when
you drive, commonly referred to as spark knock.
If this occurs, use a gasoline rated at 87 octane
or higher as soon as possible. If you are using
gasoline rated at 87 octane or higher and you hear
heavy knocking, your engine needs service.
470