coolant level GMC SIERRA 1500 2012 Owners Manual

Black plate (42,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
5-42 Instruments and Controls
SeeOverheated Engine Protection
Operating Mode on page 10‑24 for
information on driving to a safe
place in an emergency.
ENGINE OVERHEATED STOP
ENGINE
This message displays and a
chime may sound if the engine
cooling system reaches unsafe
temperatures for operation. Stop
and turn off the vehicle as soon as
it is safe to do so to avoid severe
damage. This message clears when
the engine has cooled to a safe
operating temperature.
Engine Oil Messages
CHANGE ENGINE OIL SOON
This message displays when the
engine oil needs to be changed.
When you change the engine oil, be
sure to reset the CHANGE ENGINE
OIL SOON message. See Engine
Oil Life System on page 10‑10 for
information on how to reset the
message. See Engine Oil on page 10‑7
andMaintenance
Schedule on page 11‑3 for more
information.
ENGINE OIL HOT IDLE
ENGINE
This message displays when the
engine oil becomes hotter than the
normal operating temperature. Stop
and allow the vehicle to idle until it
cools down. See Engine Coolant
Temperature Gauge on page 5‑16.
OIL PRESSURE LOW STOP
ENGINE
Notice: If you drive the vehicle
while the engine oil pressure is
low, severe engine damage may
occur. If a low oil pressure
warning appears on the Driver
Information Center (DIC), stop the
vehicle as soon as possible. Do
not drive the vehicle until the
cause of the low oil pressure is
corrected. See Engine Oil on
page 10‑7 for more information. This message displays if low oil
pressure levels occur. Stop the
vehicle as soon as safely possible
and do not operate it until the cause
of the low oil pressure has been
corrected. Check the oil as soon
as possible and have the vehicle
serviced by your dealer. See
Engine
Oil on page 10‑7.
Engine Power Messages
ENGINE POWER IS REDUCED
This message displays and a chime
may sound when the cooling system
temperature gets too hot and the
engine further enters the engine
coolant protection mode. See
Engine Overheating on page 10‑22
for more information.
This message also displays when
the vehicle's engine power is
reduced. Reduced engine power
can affect the vehicle's ability to
accelerate. If this message is
on, but there is no reduction in
performance, proceed to your
destination. The performance may

Black plate (7,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Climate Controls 8-7
help quickly cool down the air
inside the vehicle. The light
on the button comes on in
recirculation.
2. Set the driver and passenger temperature.
To find your comfort setting, start
with a 23°C (74°F) temperature
setting and allow about
20 minutes for the system to
regulate. Use the driver or
passenger temperature buttons
to adjust the temperature setting
as necessary. If a temperature
setting of 15°C (60°F) is chosen,
the system remains at the
maximum cooling setting. If a
temperature setting of 32°C
(90°F) is chosen, the system
remains at the maximum heat
setting. Choosing either
maximum setting will not cause
the vehicle to heat or cool any
faster.
Do not cover the solar sensor
located on the top of the instrument
panel near the windshield. This sensor regulates air temperature
based on sun load. For more
information on the solar sensor, see
“Sensors”
later in this section.
To avoid blowing cold air in cold
weather, the system delays turning
the fan on until warm air is
available. The length of delay
depends on the engine coolant
temperature. Pressing the fan
switch overrides this delay and
changes the fan to a selected
speed.
Manual Operation
D C(Fan Control): Press these
buttons to increase or decrease the
fan speed.
Pressing either fan button while in
automatic control places the fan
under manual control. The fan
setting remains displayed and the
AUTO light turns off. The air
delivery mode remains under
automatic control.
H G(Air Delivery Mode Control):
Press these buttons to change the
direction of the airflow in the vehicle.
Repeatedly press either button until
the desired mode appears on the
display.
Pressing either mode button while
the system is off changes the air
delivery mode without turning the
system on.
Pressing either mode button while
in automatic control places the
mode under manual control. The air
delivery mode setting displays and
the AUTO light turns off. The fan
remains under automatic control.
H(Vent): Air is directed to the
instrument panel outlets.
)(Bi-Level): Air is divided
between the instrument panel and
floor outlets. Some air is directed
toward the windshield and side
window outlets.

Black plate (30,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
9-30 Driving and Operating
Engine Coolant Heater
The engine heater can provide
easier starting and better fuel
economy during engine warm-up
in cold weather conditions at or
below−18°C (0°F). Vehicles with an
engine heater should be plugged in
at least four hours before starting.
An internal thermostat in the
plug-end of the cord may exist
which will prevent engine coolant
heater operation at temperatures
above −18°C (0°F).
If the vehicle has a diesel engine,
see the Duramax Diesel supplement
for more information.
To Use the Engine Coolant
Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical cord. The cord
is secured to the Engine
Compartment Fuse Block with
a clip. Carefully remove the wire tie which bundles the
electrical plug. Do not cut the
electrical cord.
3. Plug the cord into a normal, grounded 110-volt AC outlet.
{WARNING
Plugging the cord into an
ungrounded outlet could cause an
electrical shock. Also, the wrong
kind of extension cord could
overheat and cause a fire. You
could be seriously injured. Plug
the cord into a properly grounded
three-prong 110-volt AC outlet.
If the cord will not reach, use a
heavy-duty three-prong extension
cord rated for at least 15 amps.
4. Before starting the engine, be sure to unplug and store the
cord as it was before to keep
it away from moving engine
parts. If you do not, it could be
damaged. The length of time the heater should
remain plugged in depends on
several factors. Ask a dealer in the
area where you will be parking the
vehicle for the best advice on this.
Shifting Into Park
{WARNING
It can be dangerous to get out of
the vehicle if the shift lever is not
fully in P (Park) with the parking
brake firmly set. The vehicle can
roll. If you have left the engine
running, the vehicle can move
suddenly. You or others could be
injured. To be sure the vehicle will
not move, even when you are on
fairly level ground, use the steps
that follow. With four-wheel
drive, if the transfer case is in
N (Neutral), the vehicle will be
free to roll, even if the shift lever
is in P (Park). So, be sure the
transfer case is in a drive
(Continued)

Black plate (76,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
9-76 Driving and Operating
Backing Up
Hold the bottom of the steering
wheel with one hand. To move the
trailer to the left, move that hand to
the left. To move the trailer to the
right, move your hand to the right.
Always back up slowly and,
if possible, have someone
guide you.
Making Turns
Notice:Making very sharp turns
while trailering could cause the
trailer to come in contact with the
vehicle. The vehicle could be
damaged. Avoid making very
sharp turns while trailering.
When turning with a trailer, make
wider turns than normal. Do this
so the trailer will not strike soft
shoulders, curbs, road signs, trees,
or other objects. Avoid jerky or
sudden maneuvers. Signal well in
advance. If the trailer turn signal bulbs burn
out, the arrows on the instrument
panel will still flash for turns. It is
important to check occasionally to
be sure the trailer bulbs are still
working.
Driving on Grades
Reduce speed and shift to a
lower gear
beforestarting down a
long or steep downgrade. If the
transmission is not shifted down, the
brakes might get hot and no longer
work well.
Vehicles can tow in D (Drive). Shift
the transmission to a lower gear if
the transmission shifts too often
under heavy loads and/or hilly
conditions.
The Tow/Haul Mode may be used if
the transmission shifts too often.
See Tow/Haul Mode on page 9‑39.
When towing at high altitude on
steep uphill grades, consider the
following: Engine coolant will boil at
a lower temperature than at normal
altitudes. If the engine is turned off immediately after towing at high
altitude on steep uphill grades, the
vehicle may show signs similar to
engine overheating. To avoid this,
let the engine run while parked,
preferably on level ground, with the
automatic transmission in P (Park)
for a few minutes before turning the
engine off. If the overheat warning
comes on, see
Engine Overheating
on page 10‑22.
Parking on Hills
{WARNING
Parking the vehicle on a hill
with the trailer attached can be
dangerous. If something goes
wrong, the rig could start to move.
People can be injured, and both
the vehicle and the trailer can be
damaged. When possible, always
park the rig on a flat surface.

Black plate (7,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Vehicle Care 10-7
A.Engine Air Cleaner/Filter on
page 10‑17.
B. Coolant Surge Tank and Pressure Cap. See Cooling
System on page 10‑18.
C. Positive (+) Terminal. See Jump
Starting on page 10‑88.
D. Battery on page 10‑30.
E. Remote Negative (−) Terminal (Out of View). See Jump
Starting on page 10‑88.
F. Automatic Transmission Dipstick (Out of View). See
“Checking the Fluid Level”
under Automatic Transmission
Fluid (4-Speed Transmission)
on page 10‑11 orAutomatic
Transmission Fluid (6-Speed
Transmission) on page 10‑14.
G. Engine Oil Fill Cap. See “When
to Add Engine Oil” under
Engine Oil on page 10‑7. H. Engine Oil Dipstick (Out of
View). See “Checking Engine
Oil” under Engine Oil on
page 10‑7.
I. Engine Cooling Fan (Out of View). See Cooling System on
page 10‑18.
J. Power Steering Fluid Reservoir. See Power Steering Fluid on
page 10‑25.
K. Brake Master Cylinder Reservoir. See Brake Fluid on
page 10‑28.
L. Engine Compartment Fuse
Block on page 10‑44.
M. Windshield Washer Fluid Reservoir. See “Adding Washer
Fluid” under Washer Fluid on
page 10‑26.
If the vehicle has a diesel engine
and/or an Allison Transmission, see
the Duramax Diesel Supplement.Engine Oil
For diesel engine vehicles, see
“Engine Oil” in the Duramax Diesel
Supplement.
To ensure proper engine
performance and long life, careful
attention must be paid to engine
oil. Following these simple, but
important steps will help protect
your investment:
.Always use engine oil approved
to the proper specification and of
the proper viscosity grade. See
“Selecting the Right Engine Oil”
in this section.
.Check the engine oil level
regularly and maintain the
proper oil level. See “Checking
Engine Oil” and“When to Add
Engine Oil” in this section.
.Change the engine oil at the
appropriate time. See Engine Oil
Life System on page 10‑10.
.Always dispose of engine oil
properly. See “What to Do with
Used Oil” in this section.

Black plate (20,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
10-20 Vehicle Care
.Will not damage aluminum parts
.Helps keep the proper engine
temperature
Notice: If an improper coolant
mixture is used, the engine could
overheat and be badly damaged.
The repair cost would not be
covered by the vehicle warranty.
Too much water in the mixture
can freeze and crack the engine,
radiator, heater core, and other
parts.
Notice: If extra inhibitors and/or
additives are used in the vehicle
cooling system, the vehicle
could be damaged. Use only the
proper mixture of the engine
coolant listed in this manual
for the cooling system. See
Recommended Fluids and
Lubricants on page 11‑12 for
more information. Never dispose of engine coolant
by putting it in the trash, pouring it
on the ground, or into sewers,
streams, or bodies of water.
Have the coolant changed by an
authorized service center, familiar
with legal requirements regarding
used coolant disposal. This will help
protect the environment and your
health.
Checking Coolant
The coolant surge tank is located in
the engine compartment on the
passenger side of the vehicle. See
Engine Compartment Overview on
page 10‑6
for more information on
location.
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 level should be at or
above the FULL COLD mark. If it is
not, there may be a leak in the
cooling system.

Black plate (22,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
10-22 Vehicle Care
3. Fill the coolant surge tank withthe proper mixture to the FULL
COLD mark.
4. With the coolant surge tank pressure cap off, start the
engine and let it run until the
engine coolant temperature
gauge indicates approximately
90°C (195°F).
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 the 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
If the vehicle has the Duramax®
Diesel engine, see the Duramax
Diesel Supplement for more
information.
The vehicle has several indicators
to warn of engine overheating. There is a coolant temperature
gauge on the vehicle's instrument
panel. See
Engine Coolant
Temperature Gauge on page 5‑16.
In addition, there are ENGINE
OVERHEATED STOP ENGINE,
ENGINE OVERHEATED IDLE
ENGINE, and ENGINE POWER IS
REDUCED messages in the Driver
Information Center (DIC) on the
instrument panel. See Engine
Cooling System Messages on
page 5‑41 andEngine Power
Messages on page 5‑42.
If the decision is made not to lift the
hood when this warning appears,
get service help right away. See
Roadside Assistance Program (U.S.
and Canada) on page 13‑7 or
Roadside 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 (3,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Service and Maintenance 11-3
Maintenance
Schedule
Owner Checks and Services
At Each Fuel Stop
.Check the engine oil level. See
Engine Oil on page 10‑7.
Once a Month
.Check the tire inflation
pressures. See Tire Pressure on
page 10‑58.
.Inspect the tires for wear. See
Tire Inspection on page 10‑65.
.Check the windshield washer
fluid level. See Washer Fluid on
page 10‑26.
Engine Oil Change
When the CHANGE ENGINE OIL
SOON message displays, have the
engine oil and filter changed within
the next 1 000 km/600 mi. If driven
under the best conditions, the
engine oil life system might not
indicate the need for vehicle service for more than a year. The engine oil
and filter must be changed at least
once a year and the oil life system
must be reset. Your trained dealer
technician can perform this work.
If the engine oil life system is reset
accidentally, service the vehicle
within 5 000 km/3,000 mi since
the last service. Reset the oil life
system when the oil is changed.
See
Engine Oil Life System on
page 10‑10.
Tire Rotation and Required
Services Every 12 000 km/
7,500 mi
Rotate the tires, if recommended
for the vehicle, and perform the
following services. See Tire
Rotation on page 10‑65.
.Check engine oil level and oil
life percentage. If needed,
change engine oil and filter, and
reset oil life system. See Engine
Oil on page 10‑7 andEngine Oil
Life System on page 10‑10.
.Check engine coolant level. See
Engine Coolant on page 10‑19.
.Check windshield washer fluid
level. See Washer Fluid on
page 10‑26.
.Visually inspect windshield
wiper blades for wear, cracking,
or contamination. See Exterior
Care on page 10‑98. Replace
worn or damaged wiper blades.
See Wiper Blade Replacement
on page 10‑36.
.Check tire inflation pressures.
See Tire Pressure on
page 10‑58.
.Inspect tire wear. See Tire
Inspection on page 10‑65.
.Visually check for fluid leaks.
.Inspect engine air cleaner filter.
See Engine Air Cleaner/Filter on
page 10‑17.
.Inspect brake system.

Black plate (4,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
11-4 Service and Maintenance
.Visually inspect steering,
suspension, and chassis
components for damaged, loose,
or missing parts or signs of
wear. SeeExterior Care on
page 10‑98.
.Check restraint system
components. See Safety System
Check on page 3‑20.
.Visually inspect fuel system for
damage or leaks.
.Visually inspect exhaust system
and nearby heat shields for
loose or damaged parts.
.Lubricate body components. See
Exterior Care on page 10‑98.
.Check starter switch. See Starter
Switch Check on page 10‑35.
.Check automatic transmission
shift lock control function. See
Automatic Transmission Shift
Lock Control Function Check on
page 10‑35.
.Check ignition transmission lock.
See Ignition Transmission Lock
Check on page 10‑35.
.Check parking brake and
automatic transmission park
mechanism. See Park Brake and
P (Park) Mechanism Check on
page 10‑36.
.Check accelerator pedal for
damage, high effort, or binding.
Replace if needed.
.Visually inspect gas strut for
signs of wear, cracks, or other
damage. Check the hold open
ability of the strut. See your
dealer if service is required.
.Inspect sunroof track and seal,
if equipped. See Sunroof (Crew
Cab) on page 2‑23 orSunroof
(Extended Cab) on page 2‑22.
.Check hybrid low pressure
coolant level, if equipped.