2007 CHEVROLET AVALANCHE light

Trailer Wiring Harness
Heavy-Duty Trailer Wiring Package
Your vehicle is equipped with the seven-wire
trailer towing harness. This harness with a
seven-pin universal heavy-duty trailer connector
is attached to the rear bumper beam. It is located
next to the integrated trailer hitch.The seven-wire harness contains the following
trailer circuits:
Yellow: Left Stop/Turn Signal
Dark Green: Right Stop/Turn Signal
Brown: Taillamps
White: Ground
Light Green: Back-up Lamps
Red: Battery Feed **#
Dark Blue: Trailer Brake #
** If you are charging a remote (non-vehicle)
battery, press the tow/haul mode button located
at the end of the shift lever. This will boost
the vehicle system voltage and properly charge
the battery. If the trailer is too light for tow/haul
mode, you can turn on the headlamps as a
second way to boost the vehicle system and
charge the battery.
# The fuses for these circuits are installed in the
underhood electrical center, but the wires are
not connected. These circuits should be connected
by your dealer or a qualied service technician.
427

Electric Brake Control Wiring
Provisions
These wiring provisions are included with your
vehicle as part of the heavy-duty trailer wiring
package. These provisions are for an electric
brake controller. The instrument panel contains
blunt cut wires near the data link connector for
the trailer brake controller. The harness contains
the following wires:
Dark Blue: Auxiliary
Red/Black: Battery #
Light Blue: Brake Switch
White: Ground
The trailer brake controller should be installed
by your dealer or a qualied service center.
Trailer Recommendations
You must subtract your hitch loads from the
Cargo Weight Rating (CWR). CWR is the
maximum weight of the load your vehicle can
carry. It doesn’t include the weight of the people
inside, but you can gure about 150 lbs. (68 kg)
for each seat. The total cargo load must not
be more than your vehicles CWR.
Weigh your vehicle with your trailer attached,
so that you won’t go over the GVWR or GAWR.
If you are using a weight-distributing hitch,
weigh the vehicle without the spring bars in place.
You’ll get the best performance if you spread
out the weight of your load the right way, and if
you choose the correct hitch and trailer brakes.
For more information seeTowing a Trailer
on page 414.
428

Fuel E85 (85% Ethanol)
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 546.
If your vehicle has the 5.3L V8 engine (Code 0)
or the 5.3L V8 engine (Code 3), you may use
either regular unleaded gasoline or ethanol fuel
containing up to 85% ethanol (E85); also see
Fuel on page 435. In all other engines, use only
the unleaded gasoline described underGasoline
Octane on page 436.
Only vehicles that have the 5.3L V8 engine
(Code 0) or the 5.3L V8 engine (Code 3) may
use 85% ethanol fuel (E85). General Motors
encourages the use of E85 in vehicles that are
designed to use it. The ethanol in E85 is a
“renewable” fuel, meaning it is made from
renewable sources such as corn and
other crops.Many service stations will not have an 85% ethanol
fuel (E85) pump available. The U. S. Department
of Energy has an alternative fuels website
(www.eere.energy.gov/afdc/infrastructure/
locator.html) that can help you nd E85 fuel.
Those stations that do have E85 should have a
label indicating ethanol content. Do not use the fuel
if the ethanol content is greater than 85%.
At a minimum, E85 should meet ASTM
Specication D 5798. By denition, this means
that fuel labeled E85 will have an ethanol content
between 70% and 85%. Filling the fuel tank
with fuel mixtures that do not meet ASTM
specications can affect driveability and could
cause the check engine light to come on.
To ensure quick starts in the wintertime, the
E85 fuel must be formulated properly for your
climate according to ASTM specication D 5798.
If you have trouble starting on E85, it may
be because your E85 fuel is not properly
formulated for your climate. If this happens,
switching to gasoline or adding gasoline
to your fuel tank may improve starting.
438

{CAUTION:
If you spill fuel and then something
ignites it, you could be badly burned.
Fuel can spray out on you if you open
the fuel cap too quickly. This spray can
happen if your tank is nearly full, and is
more likely in hot weather. Open the fuel
cap slowly and wait for any hiss noise to
stop. Then unscrew the cap all the way.
Be careful not to spill fuel. Do not top off or overll
the tank and wait a few seconds after you have
nished pumping before removing the nozzle.
Clean fuel from painted surfaces as soon as
possible. SeeWashing Your Vehicle on page 541.
When replacing the fuel cap, turn it clockwise
until it clicks. It will require more effort to turn
the fuel cap on the last turn as you tighten it.
Make sure the cap is fully installed. The diagnostic
system can determine if the fuel cap has been
left off or improperly installed. This would allow
fuel to evaporate into the atmosphere. See
Malfunction Indicator Lamp on page 250.The TIGHTEN GAS CAP message will be
displayed on the Driver Information Center (DIC)
if the fuel cap is not properly installed. See
DIC Warnings and Messages on page 267for
more information.
{CAUTION:
If a re starts while you are refueling,
do not remove the nozzle. Shut off the
ow of fuel by shutting off the pump
or by notifying the station attendant.
Leave the area immediately.
Notice:If you need a new fuel cap, be sure
to get the right type. Your dealer can get
one for you. If you get the wrong type,
it may not t properly. This may cause your
malfunction indicator lamp to light and
may damage your fuel tank and emissions
system. SeeMalfunction Indicator Lamp
on page 250.
441

Vehicles Without an Air Filter Restriction
Indicator
To inspect the air cleaner/lter, remove the engine
air cleaner/lter from the vehicle by following
Steps 1 through 6. When you have the engine
air cleaner/lter removed, lightly shake it to release
loose dust and dirt. If the engine air cleaner/lter
remains caked with dirt, a new lter is required.
Replacing the Engine Air Cleaner/Filter and
Resetting the Air Filter Restriction Indicator
1. Locate the air cleaner/lter assembly. See
Engine Compartment Overview on page 444.
2. Loosen the four screws on the cover of the
housing and lift up the cover.
452

The following explains your cooling system and
how to add coolant when it is low. If you have
a problem with engine overheating, seeEngine
Overheating on page 460.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Give freezing protection down to−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as
they should.
Notice:Using coolant other than DEX-COOL
®
may cause premature engine, heater core,
or radiator corrosion. In addition, the engine
coolant may require changing sooner, at
the rst maintenance service after each
30,000 miles (50 000 km) or 24 months,
whichever occurs rst. Any repairs would
not be covered by your warranty. Always
use DEX-COOL
®(silicate-free) coolant in
your vehicle.
What to Use
Use a mixture of one-half clean, drinkable water
and one-half DEX-COOL®coolant which will
not damage aluminum parts. If you use this coolant
mixture, you do not need to add anything else.
{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can
boil before the proper coolant mixture will.
Your vehicle’s coolant warning system is
set for the proper coolant mixture. With
plain water or the wrong mixture, your
engine could get too hot but you would
not get the overheat warning. Your engine
could catch re and you or others could
be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.
458

Brakes
Brake Fluid
Your brake master
cylinder reservoir is
lled with DOT-3 brake
uid. SeeEngine
Compartment Overview
on page 444for the
location of the reservoir.
There are only two reasons why the brake uid
level in the reservoir might go down. The rst
is that the brake uid goes down to an acceptable
level during normal brake lining wear. When
new linings are put in, the uid level goes back
up. The other reason is that uid is leaking out of
the brake system. If it is, you should have your
brake system xed, since a leak means that
sooner or later your brakes will not work well,
or will not work at all.So, it is not a good idea to top off your brake uid.
Adding brake uid will not correct a leak. If you
add uid when your linings are worn, then you
will have too much uid when you get new brake
linings. You should add or remove brake uid,
as necessary, only when work is done on
the brake hydraulic system.
{CAUTION:
If you have too much brake uid, it can
spill on the engine. The uid will burn
if the engine is hot enough. You or others
could be burned, and your vehicle could
be damaged. Add brake uid only when
work is done on the brake hydraulic
system. See “Checking Brake Fluid”
in this section.
When the brake uid falls to a low level, the brake
warning light will come on. SeeBrake System
Warning Light on page 246.
Refer to the Maintenance Schedule to determine
when to check your brake uid. SeeScheduled
Maintenance on page 563.
472

Brake Wear
Your vehicle has four-wheel disc brakes.
Disc brake pads have built-in wear indicators that
make a high-pitched warning sound when the
brake pads are worn and new pads are needed.
The sound may come and go or be heard all
the time your vehicle is moving, except when
you are pushing on the brake pedal rmly.
{CAUTION:
The brake wear warning sound means that
soon the brakes will not work well. That
could lead to an accident. When you hear
the brake wear warning sound, have your
vehicle serviced.
Notice:Continuing to drive with worn-out
brake pads could result in costly brake repair.Some driving conditions or climates may cause a
brake squeal when the brakes are rst applied
or lightly applied. This does not mean something
is wrong with your brakes.
Properly torqued wheel nuts are necessary to help
prevent brake pulsation. When tires are rotated,
inspect brake pads for wear and evenly tighten
wheel nuts in the proper sequence to GM torque
specications.
Brake linings should always be replaced as
complete axle sets.
Brake Pedal Travel
See your dealer if the brake pedal does not return
to normal height, or if there is a rapid increase
in pedal travel. This could be a sign of brake
trouble.
Brake Adjustment
Every time you make a brake stop, your disc
brakes adjust for wear.
474