cooling CHEVROLET SUBURBAN 2012 10.G Owner's Manual

Black plate (17,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
Vehicle Care 10-17
center, familiar with legal
requirements regarding used
coolant disposal. This will help
protect the environment and your
health.
Checking Coolant
The vehicle must be on a level
surface when checking the coolant
level.
Check to see if coolant is visible in
the coolant surge tank. If the coolant
inside the coolant surge tank is
boiling, do not do anything else until
it cools down. If coolant is visible
but the coolant level is not at or
above the FULL COLD mark, add a
50/50 mixture of clean, drinkable
water and DEX-COOL coolant at the
coolant surge tank, but be sure the
cooling system is cool before this
is done.
The coolant surge tank is located in
the engine compartment on the
passenger side of the vehicle. See
Engine Compartment Overview on
page 10‑6for more information on
location.
The coolant level should be at or
above the FULL COLD mark. If it is
not, the vehicle may have a leak in
the cooling system.
How to Add Coolant to the
Surge Tank
{WARNING
You can be burned if you spill
coolant on hot engine parts.
Coolant contains ethylene glycol
and it will burn if the engine parts
are hot enough. Do not spill
coolant on a hot engine.
Notice: This vehicle has a
specific coolant fill procedure.
Failure to follow this procedure
could cause the engine to
overheat and be severely
damaged.
{WARNING
An electric engine cooling fan
under the hood can start up even
when the engine is not running
and can cause injury. Keep
hands, clothing, and tools away
from any underhood electric fan.

Black plate (18,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
10-18 Vehicle Care
{WARNING
Steam and scalding liquids from a
hot cooling system can blow out
and burn you badly. They are
under pressure, and if you turn
the surge tank pressure
cap—even a little —they can
come out at high speed. Never
turn the cap when the cooling
system, including the surge tank
pressure cap, is hot. Wait for the
cooling system and surge tank
pressure cap to cool if you ever
have to turn the pressure cap. If no coolant is visible in the surge
tank, add coolant as follows:
1. Remove the coolant surge tank
pressure cap when the cooling
system, including the coolant
surge tank pressure cap and
upper radiator hose, is no
longer hot.
Turn the pressure cap slowly
counterclockwise about one full
turn. If a hiss is heard, wait for
that to stop. A hiss means there
is still some pressure left.
2. Keep turning the pressure cap slowly and remove it.
3. Fill the coolant surge tank with
the proper mixture to the FULL
COLD mark.

Black plate (19,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
Vehicle Care 10-19
4. With the coolant surge tankpressure cap off, start the
engine and let it run until the
upper radiator hose can be felt
getting hot. Watch out for the
engine cooling fan.
By this time, the coolant level
inside the coolant surge tank
may be lower. If the level is
lower, add more of the proper
mixture to the coolant surge tank
until the level reaches the FULL
COLD mark. 5. Replace the pressure cap. Be
sure the pressure cap is
hand-tight and fully seated.
6. Verify coolant level after engine is shut off and the coolant is
cold. If necessary, repeat coolant
fill procedure Steps 1 through 6.
Notice: If the pressure cap is not
tightly installed, coolant loss and
possible engine damage may
occur. Be sure the cap is properly
and tightly secured.
Engine Overheating
The vehicle has several indicators
to warn of engine overheating.
There is a coolant temperature
gauge on your vehicle's instrument
panel. See Engine Coolant
Temperature Gauge on page 5‑14. In addition, ENGINE OVERHEATED
STOP ENGINE, ENGINE
OVERHEATED IDLE ENGINE, and
an ENGINE POWER IS REDUCED
message comes on in the Driver
Information Center (DIC) on the
instrument panel. See
Engine
Cooling System Messages on
page 5‑37 andEngine Power
Messages on page 5‑39.
If the decision is made not to lift the
hood when this warning appears,
but instead get service help right
away. See Roadside Assistance
Program (U.S. and Canada) on
page 13‑7 orRoadside Assistance
Program (Mexico) on page 13‑9.
If the decision is made to lift the
hood, make sure the vehicle is
parked on a level surface.

Black plate (20,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
10-20 Vehicle Care
Then check to see if the engine
cooling fans are running. If the
engine is overheating, both fans
should be running. If they are not,
do not continue to run the engine
and have the vehicle serviced.
Notice:Engine damage from
running the engine without
coolant is not covered by
the vehicle warranty. See
Overheated Engine Protection
Operating Mode on page 10‑21 for
information on driving to a safe
place in an emergency.
Notice: If the engine catches fire
while driving with no coolant, the
vehicle can be badly damaged.
The costly repairs would not
be covered by the vehicle
warranty. See Overheated Engine
Protection Operating Mode on
page 10‑21 for information on
driving to a safe place in an
emergency.If Steam Is Coming from the
Engine Compartment
{WARNING
Steam from an overheated engine
can burn you badly, even if you
just open the hood. Stay away
from the engine if you see or hear
steam coming from it. Turn it off
and get everyone away from the
vehicle until it cools down. Wait
until there is no sign of steam
or coolant before you open
the hood.
If you keep driving when the
vehicles engine is overheated,
the liquids in it can catch fire. You
or others could be badly burned.
Stop the engine if it overheats,
and get out of the vehicle until the
engine is cool.
(Continued)
WARNING (Continued)
SeeOverheated Engine
Protection Operating Mode on
page 10‑21 for information on
driving to a safe place in an
emergency.
If No Steam Is Coming from
the Engine Compartment
The ENGINE OVERHEATED
STOP ENGINE or the ENGINE
OVERHEATED IDLE ENGINE
message, along with a low coolant
condition, can indicate a serious
problem.
If an engine overheat warning is
displayed but no steam can be seen
or heard, the problem may not be
too serious. Sometimes the engine
can get a little too hot when the
vehicle:
.Climbs a long hill on a hot day.
.Stops after high-speed driving.

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 (40,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
10-40 Vehicle Care
FusesUsage
33 Daytime Running
Lamps 2 (If Equipped)
34 Sunroof
35 Key Ignition System,
Theft Deterrent
System
36 Windshield Wiper
37 SEO B2 Upfitter
Usage (Battery)
38 Electric Adjustable
Pedals
39 Climate Controls
(Battery)
40 Airbag System
(Ignition)
41 Amplifier
42 Audio System
43 Miscellaneous
(Ignition), Cruise
Control Fuses
Usage
44 Liftgate Release
45 Airbag System
(Battery)
46 Instrument Panel
Cluster
47 Not Used
48 Auxiliary Climate
Control (Ignition)
49 Center High-Mounted
Stoplamp (CHMSL)
50 Rear Defogger
51 Heated Mirrors
52 SEO B1 Upfitter
Usage (Battery)
53 Accessory Power
Outlet
54 Automatic Level
Control Compressor
Relay Fuses
Usage
55 Climate Controls
(Ignition)
56 Engine Control
Module, Secondary
Fuel Pump (Ignition)
J-Case Fuses Usage
57 Cooling Fan 1
58 Automatic Level
Control Compressor
59 Heavy Duty Antilock
Braking System
60 Cooling Fan 2
61 Antilock Brake
System 1
62 Starter
63 Stud 2 (Trailer
Brakes)
64 Left Bussed Electrical
Center 1

Black plate (41,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
Vehicle Care 10-41
J-CaseFuses Usage
65 Electric Running
Boards
66 Not Used
67 Transfer Case
68 Stud 1 (Trailer
Connector Battery
Power)
69 Mid-Bussed Electrical
Center 1
70 Climate Control
Blower
71 Power Liftgate
Module
72 Left Bussed Electrical
Center 2
Relays Usage
FAN HI Cooling Fan High
Speed
FAN LO Cooling Fan Low
Speed Relays Usage
FAN
CNTRL Cooling Fan Control
HDLP
LO/HID Low-Beam Headlamp
FOG
LAMP Front Fog Lamps
A/C
CMPRSR Air Conditioning
Compressor
STRTR Starter
PWR/TRN Powertrain
FUEL
PMP Fuel Pump
PRK
LAMP Parking Lamps
REAR
DEFOG Rear Defogger
RUN/
CRNK Switched PowerInstrument Panel Fuse
Block
The instrument panel fuse block
access door is located on the driver
side edge of the instrument panel.
Pull off the cover to access the fuse
block.

Black plate (63,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
Vehicle Care 10-63
to sudden tire failure. The
grade C corresponds to a
level of performance which all
passenger car tires must meet
under the Federal Motor Safety
Standard No. 109. Grades B
and A represent higher levels of
performance on the laboratory
test wheel than the minimum
required by law. Warning: The
temperature grade for this tire is
established for a tire that is
properly inflated and not
overloaded. Excessive speed,
underinflation, or excessive
loading, either separately or in
combination, can cause heat
buildup and possible tire failure.
Wheel Alignment and Tire
Balance
The tires and wheels were aligned
and balanced at the factory to
provide the longest tire life and best
overall performance. Adjustments to
wheel alignment and tire balancingwill not be necessary on a regular
basis. However, check the
alignment if there is unusual tire
wear or if the vehicle is pulling to
one side or the other. If the vehicle
vibrates when driving on a smooth
road, the tires and wheels might
need to be rebalanced. See your
dealer for proper diagnosis.
Wheel Replacement
Replace any wheel that is bent,
cracked, or badly rusted or
corroded. If wheel nuts keep coming
loose, the wheel, wheel bolts, and
wheel nuts should be replaced.
If the wheel leaks air, replace it.
Some aluminum wheels can be
repaired. See your dealer if any of
these conditions exist.
Your dealer will know the kind of
wheel that is needed.
Each new wheel should have the
same load-carrying capacity,
diameter, width, offset, and be
mounted the same way as the one it
replaces.
Replace wheels, wheel bolts, wheel
nuts, or Tire Pressure Monitor
System (TPMS) sensors with new
GM original equipment parts.
{WARNING
Using the wrong replacement
wheels, wheel bolts, or wheel
nuts can be dangerous. It could
affect the braking and handling of
the vehicle. Tires can lose air,
and cause loss of control, causing
a crash. Always use the correct
wheel, wheel bolts, and wheel
nuts for replacement.
Notice: The wrong wheel can
also cause problems with bearing
life, brake cooling, speedometer
or odometer calibration,
headlamp aim, bumper height,
vehicle ground clearance, and tire
or tire chain clearance to the
body and chassis.
See If a Tire Goes Flat on
page 10‑65 for more information.

Black plate (6,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
11-6 Service and Maintenance
Footnotes—Maintenance
Schedule Additional Required
Services —Normal
a) Check all fuel and vapor lines
and hoses for proper hook‐up,
routing, and condition. Check that
the purge valve, if the vehicle has
one, works properly. Replace as
needed.
b) Or every four years, whichever
comes first. c)
Do not directly power wash the
transfer case output seals. High
pressure water can overcome the
seals and contaminate the transfer
case fluid. Contaminated fluid will
decrease the life of the transfer
case and should be replaced. d)
Or every five years, whichever
comes first. See Cooling System on
page 10‑15.
e) Or every 10 years, whichever
comes first. Inspect for fraying,
excessive cracking, or damage;
replace, if needed.