CHEVROLET SUBURBAN 2012 10.G Owners Manual

Black plate (21,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
Vehicle Care 10-21
.Idles for long periods in traffic.
.Tows a trailer. SeeTrailer
Towing on page 9‑70.
If the overheat warning is displayed
with no sign of steam:
1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and to the highest
fan speed. Open the windows as
necessary.
3. In heavy traffic, let the engine idle in N (Neutral) while stopped.
If it is safe to do so, pull off
the road, shift to P (Park) or
N (Neutral) and let the
engine idle.
If the temperature overheat gauge
is no longer in the overheat zone
or an overheat warning no longer
displays, the vehicle can be driven.
Continue to drive the vehicle slowly
for about 10 minutes. Keep a safe
vehicle distance from the vehicle in
front. If the warning does not come
back on, continue to drive normally. If the warning continues, pull over,
stop, and park the vehicle
right away.
If there is no sign of steam, idle
the engine for three minutes while
parked. If the warning is still
displayed, turn off the engine until it
cools down. Also, see
“Overheated
Engine Protection Operating Mode”
later in this section.
Overheated Engine
Protection
Operating Mode
If an overheated engine condition
exists and the ENGINE POWER IS
REDUCED message is displayed,
an overheat protection mode which
alternates firing groups of cylinders
helps prevent engine damage. In
this mode, a loss in power and
engine performance will be noticed.
This operating mode allows the
vehicle to be driven to a safe place
in an emergency. Driving extended distances and/or towing a trailer
in the overheat protection mode
should be avoided.
Notice:
After driving in the
overheated engine protection
operating mode, to avoid engine
damage, allow the engine to cool
before attempting any repair.
The engine oil will be severely
degraded. Repair the cause of
coolant loss, change the oil and
reset the oil life system. See
Engine Oil on page 10‑7.
Engine Fan
If the vehicle has a clutched engine
cooling fan, when the clutch is
engaged, the fan spins faster to
provide more air to cool the engine.
In most everyday driving conditions,
the fan is spinning slower and
the clutch is not fully engaged.

Black plate (22,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
10-22 Vehicle Care
This improves fuel economy and
reduces fan noise. Under heavy
vehicle loading, trailer towing, and/
or high outside temperatures, the
fan speed increases as the clutch
more fully engages, so an increase
in fan noise may be heard. This is
normal and should not be mistaken
as the transmission slipping or
making extra shifts. It is merely the
cooling system functioning properly.
The fan will slow down when
additional cooling is not required
and the clutch disengages.
This fan noise may also be heard
when starting the engine. It will go
away as the fan clutch partially
disengages.
If the vehicle has electric cooling
fans, the fans may be heard
spinning at low speed during
most everyday driving. The fans
may turn off if no cooling is required.
Under heavy vehicle loading, trailer
towing, high outside temperatures,
or operation of the air conditioning
system, the fans may change to
high speed and an increase in fannoise may be heard. This is normal
and indicates that the cooling
system is functioning properly. The
fans will change to low speed when
additional cooling is no longer
required.
Power Steering Fluid
If the vehicle is a hybrid, see the
hybrid supplement for more
information.
See
Engine Compartment Overview
on page 10‑6 for reservoir location.
When to Check Power Steering
Fluid
It is not necessary to regularly
check power steering fluid unless
there is a leak suspected in the
system or an unusual noise is heard. A fluid loss in this system
could indicate a problem. Have the
system inspected and repaired.
How to Check Power Steering
Fluid
Notice:
Extremely small amounts
of contamination can cause
steering system damage and
cause it to not work properly. Do
not allow contaminants to contact
the fluid side of the reservoir
cap/dipstick or from entering the
reservoir.
To check the power steering fluid:
1. Turn the key off and let the engine compartment cool down.
2. Wipe the cap and the top of the reservoir clean.
3. Unscrew the cap and wipe the dipstick with a clean rag.
4. Replace the cap and completely tighten it.
5. Remove the cap again and look at the fluid level on the dipstick.

Black plate (23,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
Vehicle Care 10-23
The level should be at the FULL
COLD mark. If necessary, add only
enough fluid to bring the level up to
the mark.
What to Use
To determine what kind of fluid to
use, seeRecommended Fluids and
Lubricants on page 11‑12. Always
use the proper fluid.
Notice: Use of the incorrect fluid
may damage the vehicle and the
damages may not be covered by
the vehicle's warranty. Always
use the correct fluid listed in
Recommended Fluids and
Lubricants on page 11‑12.
Washer Fluid
What to Use
When windshield washer fluid needs
to be added, be sure to read the
manufacturer's instructions before
use. Use a fluid that has sufficient
protection against freezing in an
area where the temperature may fall
below freezing.
Adding Washer Fluid
The vehicle has a low washer fluid
message on the DIC that comes
on when the washer fluid 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, washer fluid will need to
be added to the windshield washer
fluid reservoir.
Open the cap with the washer
symbol on it. Add washer fluid
until the tank is full. See Engine
Compartment Overview on
page 10‑6 for reservoir location. Notice
.When using concentrated
washer fluid, follow the
manufacturer's instructions
for adding water.
.Do not mix water with
ready-to-use washer fluid.
Water can cause the solution
to freeze and damage the
washer fluid tank and other
parts of the washer system.
Also, water does not clean as
well as washer fluid.
.Fill the washer fluid tank
only three-quarters full
when it is very cold. This
allows for fluid expansion
if freezing occurs, which
could damage the tank if it is
completely full.
.Do not use engine coolant
(antifreeze) in the windshield
washer. It can damage the
windshield washer system
and paint.

Black plate (24,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
10-24 Vehicle Care
Brakes
This vehicle has 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 can come and go or be
heard all the time the vehicle is
moving, except when applying the
brake pedal firmly.
{WARNING
The brake wear warning sound
means that soon the brakes will
not work well. That could lead to
a crash. When the brake wear
warning sound is heard, have the
vehicle serviced.
Notice: Continuing to drive with
worn-out brake pads could result
in costly brake repair. Some driving conditions or climates
can cause a brake squeal when the
brakes are first applied or lightly
applied. This does not mean
something is wrong with the 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 torque
specifications in
Capacities and
Specifications on page 12‑2.
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
that brake service might be
required.
Brake Adjustment
Every time the brakes are applied,
with or without the vehicle moving,
the brakes adjust for wear.
Replacing Brake System Parts
The braking system on a vehicle is
complex. Its many parts have to be
of top quality and work well together
if the vehicle is to have really good
braking. The vehicle was designed
and tested with top-quality brake
parts. When parts of the braking
system are replaced, be sure to get
new, approved replacement parts.
If this is not done, the brakes might
not work properly. For example,
installing disc brake pads that are
wrong for the vehicle, can change
the balance between the front and
rear brakes —for the worse. The
braking performance expected can
change in many other ways if the
wrong replacement brake parts are
installed.

Black plate (25,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
Vehicle Care 10-25
Brake Fluid
The brake master cylinder reservoir
is filled with DOT 3 brake fluid. See
Engine Compartment Overview on
page 10‑6for the location of the
reservoir.
There are only two reasons why the
brake fluid level in the reservoir
might go down:
.The brake fluid level goes down
because of normal brake lining
wear. When new linings are
installed, the fluid level goes
back up.
.A fluid leak in the brake
hydraulic system can also cause
a low fluid level. Have the brake
hydraulic system fixed, since a
leak means that sooner or later
the brakes will not work well. Do not top off the brake fluid.
Adding fluid does not correct a
leak. If fluid is added when the
linings are worn, there will be too
much fluid when new brake linings
are installed. Add or remove brake
fluid, as necessary, only when work
is done on the brake hydraulic
system.
{WARNING
If too much brake fluid is added, it
can spill on the engine and burn,
if the engine is hot enough. You
or others could be burned, and
the vehicle could be damaged.
Add brake fluid only when work is
done on the brake hydraulic
system. See
“Checking Brake
Fluid” in this section.
When the brake fluid falls to a low
level, the brake warning light comes
on. See Brake System Warning
Light on page 5‑21. Refer to the Maintenance Schedule
to determine when to check the
brake fluid. See
Maintenance
Schedule on page 11‑3.
Checking Brake Fluid
Check brake fluid by looking at the
brake fluid reservoir. See Engine
Compartment Overview on
page 10‑6.
The fluid level should be above
MIN. If it is not, have the brake
hydraulic system checked to see if
there is a leak.

Black plate (26,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
10-26 Vehicle Care
After work is done on the brake
hydraulic system, make sure the
level is above the MIN but not over
the MAX mark.
What to Add
Use only new DOT 3 brake fluid
from a sealed container. See
Recommended Fluids and
Lubricants on page 11‑12.
Always clean the brake fluid
reservoir cap and the area around
the cap before removing it. This
helps keep dirt from entering the
reservoir.
{WARNING
With the wrong kind of fluid in
the brake hydraulic system, the
brakes might not work well. This
could cause a crash. Always use
the proper brake fluid.Notice
.Using the wrong fluid
can badly damage brake
hydraulic system parts. For
example, just a few drops of
mineral-based oil, such as
engine oil, in the brake
hydraulic system can
damage brake hydraulic
system parts so badly that
they will have to be replaced.
Do not let someone put in
the wrong kind of fluid.
.If brake fluid is spilled on the
vehicle's painted surfaces,
the paint finish can be
damaged. Be careful not
to spill brake fluid on the
vehicle. If you do, wash it off
immediately.
Battery
If the vehicle is a hybrid, see the
hybrid supplement for more
information. Refer to the replacement number
on the original battery label when a
new battery is needed. See
Engine
Compartment Overview on
page 10‑6 for battery location.
{WARNING
Battery posts, terminals, and
related accessories contain lead
and lead compounds, chemicals
known to the State of California to
cause cancer and reproductive
harm. Wash hands after handling.
Vehicle Storage
{WARNING
Batteries have acid that can burn
you and gas that can explode.
You can be badly hurt if you are
not careful. See Jump Starting on
page 10‑82 for tips on working
around a battery without
getting hurt.

Black plate (27,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
Vehicle Care 10-27
Infrequent Usage: Remove the
black, negative (−) cable from the
battery to keep the battery from
running down.
Extended Storage: Remove the
black, negative (−) cable from the
battery or use a battery trickle
charger.
Four-Wheel Drive
Transfer Case
When to Check Lubricant
Refer toMaintenance Schedule on
page 11‑3 to determine when to
check the lubricant. How to Check LubricantActive Transfer Case
A. Fill Plug
B. Drain Plug
To get an accurate reading, the
vehicle should be on a level
surface.
If the level is below the bottom of
the fill plug hole, some lubricant will
need to be added. Add enough
lubricant to raise the level to the
bottom of the fill plug hole. Use care
not to overtighten the plug. When to Change Lubricant
Refer to
Maintenance Schedule on
page 11‑3 to determine how often to
change the lubricant.
What to Use
Refer to Recommended Fluids and
Lubricants on page 11‑12 to
determine what kind of lubricant
to use.
Front Axle
When to Check and Change
Lubricant
It is not necessary to regularly
check front axle fluid unless a leak
is suspected, or an unusual noise is
heard. A fluid loss could indicate a
problem. Have it inspected and
repaired.

Black plate (28,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
10-28 Vehicle Care
How to Check Lubricant
To get an accurate reading, the
vehicle should be on a level
surface.
1500 Series
A. Fill Plug
B. Drain Plug
All Except 1500 Series
A. Fill Plug
B. Drain Plug
.When the differential is cold, add
enough lubricant to raise the
level from 0 mm (0 in) to 3.2 mm
(1/8 in) below the fill plug hole.
.When the differential is at
operating temperature (warm),
add enough lubricant to raise the
level to the bottom of the fill
plug hole. What to Use
Refer to
Recommended Fluids and
Lubricants on page 11‑12 to
determine what kind of lubricant
to use.
Rear Axle
When to Check Lubricant
It is not necessary to regularly
check rear axle fluid unless there is
a leak suspected, or an unusual
noise is heard. A fluid loss could
indicate a problem. Have it
inspected and repaired.
All axle assemblies are filled by
volume of fluid during production.
They are not filled to reach a
certain level. When checking the
fluid level on any axle, variations in
the readings can be caused by
factory fill differences between the
minimum and the maximum fluid
volume. Also, if a vehicle has just
been driven before checking the
fluid level, it may appear lower than
normal because fluid has traveled

Black plate (29,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
Vehicle Care 10-29
out along the axle tubes and has
not drained back to the sump
area. Therefore, a reading taken
five minutes after the vehicle has
been driven will appear to have a
lower fluid level than a vehicle that
has been stationary for an hour or
two. Remember that the rear axle
assembly must be supported to get
a true reading.
How to Check Lubricant
1500 Series
2500 Series
To get an accurate reading, the
vehicle should be on a level
surface.
.For the 1500 series, the proper
level is from 1.0 mm to 19.0 mm
(0.04 in to 0.75 in) below the
bottom of the fill plug hole,
located on the rear axle. Add
only enough fluid to reach the
proper level.
.For the 2500 series, the proper
level is from 0 mm to 13 mm
(0 in to 1/2 in) below the bottom
of the fill plug hole, located at the front of the axle. Add only
enough fluid to reach the proper
level.
Starter Switch Check
{WARNING
When you are doing this
inspection, the vehicle could
move suddenly. If the vehicle
moves, you or others could be
injured.
1. Before starting this check, be sure there is enough room
around the vehicle.
2. Firmly apply both the parking brake and the regular brake.
See Parking Brake on
page 9‑44.
Do not use the accelerator
pedal, and be ready to turn off
the engine immediately if it
starts.

Black plate (30,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
10-30 Vehicle Care
3. Try to start the engine in eachgear. The vehicle should start
only in P (Park) or N (Neutral).
If the vehicle starts in any other
position, contact your dealer for
service.
Automatic Transmission
Shift Lock Control
Function Check
{WARNING
When you are doing this
inspection, the vehicle could
move suddenly. If the vehicle
moves, you or others could be
injured.
1. Before starting this check, be sure there is enough room
around the vehicle. It should be
parked on a level surface.
2. Firmly apply the parking brake. See Parking Brake on
page 9‑44. Be ready to apply the regular
brake immediately if the vehicle
begins to move.
3. With the engine off, turn the ignition on, but do not start the
engine. Without applying the
regular brake, try to move the
shift lever out of P (Park) with
normal effort. If the shift lever
moves out of P (Park), contact
your dealer for service.
Ignition Transmission
Lock Check
While parked, and with the parking
brake set, try to turn the ignition to
LOCK/OFF in each shift lever
position.
.The ignition should turn to
LOCK/OFF only when the shift
lever is in P (Park).
.The ignition key should come
out only in LOCK/OFF.
Contact your dealer if service is
required.
Park Brake and P (Park)
Mechanism Check
{WARNING
When you are doing this check,
the vehicle could begin to move.
You or others could be injured
and property could be damaged.
Make sure there is room in front
of the vehicle in case it begins to
roll. Be ready to apply the regular
brake at once should the vehicle
begin to move.
Park on a fairly steep hill, with the
vehicle facing downhill. Keeping
your foot on the regular brake, set
the parking brake.
.To check the parking brake's
holding ability: With the engine
running and the transmission in
N (Neutral), slowly remove foot
pressure from the regular brake
pedal. Do this until the vehicle is
held by the parking brake only.