cooling GMC SIERRA 1500 2012 Owner's Guide

Black plate (25,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Vehicle Care 10-25
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 fan
noise may be heard. This is normal
and indicates that the coolingsystem is functioning properly. The
fans will change to low speed when
additional cooling is no longer
required.
Power Steering Fluid
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 to enter 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.
The level should be at the FULL
COLD mark. If necessary, add only
enough fluid to bring the level up to
the mark.

Black plate (47,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Vehicle Care 10-47
FusesUsage
51 Heated Mirrors
52 SEO B1 Upfitter Usage
(Battery)
53 Accessory Power Outlet
54 SEO Upfitter Usage
55 Climate Controls (Ignition)
56 Engine Control Module,
Secondary Fuel Pump
(Ignition)
J-Case Fuses Usage
57 Cooling Fan 1
58 Not Used
59 Heavy Duty Antilock
Brake System
60 Cooling Fan 2
61 Antilock Brake
System 1 J-Case
Fuses Usage
62 Starter
63 Stud 2 (Trailer Brakes)
64 Left Bussed Electrical
Center 1
65 Not Used
66 Not Used
67 Transfer Case
68 Stud 1 (Trailer
Connector
Battery Power)
(Optional - 40A Fuse
Required)
69 Mid-Bussed Electrical
Center 1
70 Climate Control Blower
71 Not Used
72 Left Bussed Electrical
Center 2 Relays
Usage
FAN HI Cooling Fan High
Speed
FAN LO Cooling Fan Low
Speed
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 Power

Black plate (73,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Vehicle Care 10-73
{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.
Whenever a wheel, wheel bolt,
or wheel nut is replaced on a dual
wheel setup, check the wheel
nut torque after 160, 1 600 and
10 000 km (100, 1,000 and 6,000 mi)
of driving. For proper torque,
see “Wheel Nut Torque” under
Capacities and Specifications on
page 12‑2.
See If a Tire Goes Flat on
page 10‑75 for more information. Used Replacement Wheels{WARNING
Replacing a wheel with a used
one is dangerous. How it has
been used or how far it has been
driven may be unknown. It could
fail suddenly and cause a crash.
When replacing wheels, use a
new GM original equipment
wheel.

Black plate (6,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
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 10‑18.
e) Or every 10 years, whichever
comes first. Inspect for fraying,
excessive cracking, or damage;
replace, if needed.

Black plate (8,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
11-8 Service and Maintenance
Footnotes—Maintenance
Schedule Additional Required
Services —Severe
a) Extreme service. For vehicles
mainly driven off‐road in four‐wheel
drive or used in farming, mining,
forestry, Department of Natural
Resources (DNR), or snow plowing.
b) 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.
c) Or every four years, whichever
comes first. d)
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.
e) Or every five years, whichever
comes first. See Cooling System on
page 10‑18.
f) Or every 10 years, whichever
comes first. Inspect for fraying,
excessive cracking, or damage;
replace, if needed.Special Application
Services
.Vehicles with Dual Wheels:
Check dual wheel nut torque
at 160 km/100 mi, 1 600 km/
1,000 mi and 9 700 km/6,000 mi.
.Severe Commercial Use
Vehicles Only: Lubricate chassis
components every 5 000 km/
3,000 mi.
.Have underbody flushing service
performed once a year.

Black plate (2,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
12-2 Technical Data
Vehicle Data
Capacities and Specifications
The following approximate capacities are given in metric and English conversions. SeeRecommended Fluids and
Lubricants on page 11‑12 for more information.
If the vehicle has a diesel engine, see the Duramax diesel supplement for more information.
Application Capacities
Metric English
Air Conditioning Refrigerant R134a For the air conditioning system refrigerant charge
amount, see the refrigerant label located under the hood. See your dealer for more information.
Cooling System
4.3L V6 1500 Series 15.6 L 16.5 qt
4.8L V8 1500 Series 16.0 L 16.9 qt
5.3L V8 1500 Series 16.0 L 16.9 qt
6.0L V8 2500 Series and 3500 Series 15.5 L 16.4 qt
6.2L V8 1500 Series 15.9 L 16.8 qt

Black plate (3,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
INDEX i-3
Carbon MonoxideEngine Exhaust . . . . . . . . . . . . . . . 9-33
Tailgate . . . . . . . . . . . . . . . . . . . . . . . 2-10
Winter Driving . . . . . . . . . . . . . . . . 9-13
Cargo Lamp . . . . . . . . . . . . . . . . . . . . 6-8
Cautions, Danger, and Warnings . . . . . . . . . . . . . . . . . . . . . . . . iv
CD Player . . . . . . . . . . . . . . . . . . . . . 7-15
CD/DVD Player . . . . . . . . . . . . . . . . 7-21
Center Console Storage . . . . . . . . 4-2
Center High-Mounted Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . . . . 10-42
Center Seat . . . . . . . . . . . . . . . . . . . . 3-4
Chains, Tire . . . . . . . . . . . . . . . . . . 10-74
Charging System Light . . . . . . . . 5-22
Check Engine Light . . . . . . . . . . . . . . . . . . 5-22
IgnitionTransmission Lock . . . . . . . . 10-35 Child Restraints
Infants and Young
Children . . . . . . . . . . . . . . . . . . . . . 3-41
Lower Anchors and Tethers for Children . . . . . . . . . 3-47
Older Children . . . . . . . . . . . . . . . . 3-39
Securing . . . . . . . . . . . . . . . . 3-55, 3-58
Systems . . . . . . . . . . . . . . . . . . . . . . 3-44
Cigarette Lighter . . . . . . . . . . . . . . . 5-10
Circuit Breakers . . . . . . . . . . . . . . 10-44
Cleaning Exterior Care . . . . . . . . . . . . . . . 10-98
Interior Care . . . . . . . . . . . . . . . 10-101
Climate Control Systems . . . 8-1, 8-4 Air Conditioning . . . . . . . . . . 8-1, 8-4
Dual Automatic . . . . . . . . . . . . . . . . 8-5
Heating . . . . . . . . . . . . . . . . . . . 8-1, 8-4
Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
Cluster, Instrument . . . . . . . . . . . . 5-12
Collision Damage Repair . . . . . 13-14
Compass . . . . . . . . . . . . . . . . . . . . . . . 5-5
Connections, OnStar
®. . . . . . . . . 14-4 Control of a Vehicle . . . . . . . . . . . . . 9-4
Convex Mirrors . . . . . . . . . . . . . . . . 2-14
Coolant
Engine . . . . . . . . . . . . . . . . . . . . . . 10-19
Engine TemperatureGauge . . . . . . . . . . . . . . . . . . . . . . 5-16
Cooling System . . . . . . . . . . . . . . . 10-18
Engine Messages . . . . . . . . . . . . 5-41
Courtesy Transportation Program . . . . . . . . . . . . . . . . . . . . . 13-13
Cruise Control . . . . . . . . . . . . . . . . . 9-58
Light . . . . . . . . . . . . . . . . . . . . . . . . . . 5-30
Cupholders . . . . . . . . . . . . . . . . . . . . . 4-1
Customer Assistance . . . . . . . . . . 13-6 Offices . . . . . . . . . . . . . . . . . . 13-4, 13-5
Text Telephone (TTY)Users . . . . . . . . . . . . . . . . . . . . . . . 13-6
Customer Information Service PublicationsOrdering Information . . . . . . 13-16
Customer Satisfaction
Procedure . . . . . . . . . . . . . . 13-1, 13-3

Black plate (4,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
i-4 INDEX
D
Damage Repair, Collision . . . . . 13-14
Danger, Warnings, andCautions . . . . . . . . . . . . . . . . . . . . . . . . iv
Data Recorders, Event . . . . . . . 13-19
Daytime Running Lamps (DRL) . . . . . . . . . . . . . . . . . . 6-3
Defensive Driving . . . . . . . . . . . . . . . 9-3
Delayed Locking . . . . . . . . . . . . . . . . 2-8
Devices, Auxiliary . . . . . . . . . . . . . 7-32
Diagnostics, OnStar
®. . . . . . . . . . 14-5
Distracted Driving . . . . . . . . . . . . . . . 9-2
Dome Lamps . . . . . . . . . . . . . . . . . . . 6-8
Door Ajar Messages . . . . . . . . . . . . . . . 5-40
Delayed Locking . . . . . . . . . . . . . . . 2-8
Locks . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
Power Locks . . . . . . . . . . . . . . . . . . . 2-8
Rear Doors . . . . . . . . . . . . . . . . . . . . 2-9
Drive Belt Routing, Engine . . . . . 12-6
Driver Information
Center (DIC) . . . . . . . . . . . . . . . . . 5-30 Driving
Characteristics and
Towing Tips . . . . . . . . . . . . . . . . . 9-74
Defensive . . . . . . . . . . . . . . . . . . . . . . 9-3
Drunk . . . . . . . . . . . . . . . . . . . . . . . . . . 9-3
For Better Fuel Economy . . . . . 1-36
Highway Hypnosis . . . . . . . . . . . . 9-12
Hill and Mountain Roads . . . . . . 9-12
If the Vehicle is Stuck . . . . . . . . . 9-15
Loss of Control . . . . . . . . . . . . . . . . 9-5
Off-Road . . . . . . . . . . . . . . . . . . . . . . 9-6
Off-Road Recovery . . . . . . . . . . . . 9-5
Vehicle Load Limits . . . . . . . . . . . 9-16
Wet Roads . . . . . . . . . . . . . . . . . . . 9-11
Winter . . . . . . . . . . . . . . . . . . . . . . . . 9-13
Dual Automatic Climate
Control System . . . . . . . . . . . . . . . . 8-5
Dual Tire Rotation . . . . . . . . . . . . . . . . . . . . 10-67
DVD Rear Seat Entertainment
System . . . . . . . . . . . . . . . . . . . . . . 7-37
DVD/CD Player . . . . . . . . . . . . . . . . 7-21
E
E85 Fuel . . . . . . . . . . . . . . . . . . . . . . . 9-71
Electrical Equipment, Add-On . . . . . . . . . . . . . . . . . . . . . 9-105
Electrical System Engine CompartmentFuse Block . . . . . . . . . . . . . . . . 10-44
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . 10-44
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . . 10-48
Overload . . . . . . . . . . . . . . . . . . . 10-43
Emergency, OnStar
®. . . . . . . . . . 14-2
Engine Air Cleaner/Filter . . . . . . . . . . . 10-17
Check and Service EngineSoon Light . . . . . . . . . . . . . . . . . . 5-22
Compartment Overview . . . . . . . 10-6
Coolant . . . . . . . . . . . . . . . . . . . . . 10-19
Coolant Heater . . . . . . . . . . . . . . . 9-30
Coolant Temperature Gauge . . . . . . . . . . . . . . . . . . . . . . 5-16
Cooling System . . . . . . . . . . . . . 10-18

Black plate (5,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
INDEX i-5
Engine (cont'd)Cooling System Messages . . . 5-41
Drive Belt Routing . . . . . . . . . . . . 12-6
Exhaust . . . . . . . . . . . . . . . . . . . . . . 9-33
Fan . . . . . . . . . . . . . . . . . . . . . . . . . 10-24
Oil Life System . . . . . . . . . . . . . 10-10
Oil Messages . . . . . . . . . . . . . . . . . 5-42
Oil Pressure Gauge . . . . . . . . . . 5-15
Overheated Protection
Operating Mode . . . . . . . . . . . 10-24
Overheating . . . . . . . . . . . . . . . . 10-22
Power Messages . . . . . . . . . . . . . 5-42
Pressure Light . . . . . . . . . . . . . . . . 5-28
Running While Parked . . . . . . . . 9-34
Starting . . . . . . . . . . . . . . . . . . . . . . . 9-27
Entry Lighting . . . . . . . . . . . . . . . . . . . 6-9
Equipment, Towing . . . . . . . . . . . . 9-94
Event Data Recorders . . . . . . . . 13-19
Exit Lighting . . . . . . . . . . . . . . . . . . . . 6-9
Extender, Safety Belt . . . . . . . . . . 3-20
Exterior Lamp Controls . . . . . . . . . 6-1
Exterior Lamps Off Reminder . . . 6-2F
Fan Engine . . . . . . . . . . . . . . . . . . . . . . 10-24
Fast Idle System . . . . . . . . . . . . . . . 9-29
Features Memory . . . . . . . . . . . . . . . . . . . . . . . 1-14
Filter,
Engine Air Cleaner . . . . . . . . . 10-17
Flash-to-Pass . . . . . . . . . . . . . . . . . . . 6-3
Flashers, Hazard Warning . . . . . . 6-5
Flat Tire . . . . . . . . . . . . . . . . . . . . . . 10-75 Changing . . . . . . . . . . . . . . . . . . . 10-76
Floor Mats . . . . . . . . . . . . . . . . . . .10-104
Fluid AutomaticTransmission . . . . . . . 10-11, 10-14
Brakes . . . . . . . . . . . . . . . . . . . . . . 10-28
Four-Wheel Drive Transfer Case . . . . . . . . . . . . . . . 9-40
Power Steering . . . . . . . . . . . . . 10-25
Washer . . . . . . . . . . . . . . . . . . . . . 10-26 Fog Lamps
Bulb Replacement . . . . . . . . . . . . . 6-6
Folding Mirrors . . . . . . . . . . . . . . . . 2-16
Four-Wheel Drive . . . . . . . 9-40, 10-30
Four-Wheel-Drive Light . . . . . . . . 5-26
Front Axle . . . . . . . . . . . . . . . . . . . . 10-31
Front Fog Lamp Light . . . . . . . . . . . . . . . . . . . . . . . . . . 5-29
Front Seats Adjustment . . . . . . . . . . . . . . . . . . . . 3-3
Heated and Ventilated . . . . . . . . . 3-9
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-68 Additives . . . . . . . . . . . . . . . . . . . . . 9-70
E85 (85% Ethanol) . . . . . . . . . . . 9-71
Economy Driving . . . . . . . . . . . . . 1-36
Filling a Portable FuelContainer . . . . . . . . . . . . . . . . . . . 9-73
Filling the Tank . . . . . . . . . . . . . . . 9-72
Foreign Countries . . . . . . . . . . . . 9-69
Gasoline Specifications . . . . . . . 9-69
Gauge . . . . . . . . . . . . . . . . . . . . . . . . 5-14
Low Fuel Warning Light . . . . . . . 5-28

Black plate (8,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
i-8 INDEX
LightsAirbag On-Off . . . . . . . . . . . . . . . . . 5-19
Airbag Readiness . . . . . . . . . . . . . 5-18
Antilock Brake System
(ABS) Warning . . . . . . . . . . . . . . 5-26
Brake System Warning . . . . . . . 5-25
Charging System . . . . . . . . . . . . . 5-22
Cruise Control . . . . . . . . . . . . . . . . 5-30
Engine Oil Pressure . . . . . . . . . . 5-28
Flash-to-Pass . . . . . . . . . . . . . . . . . . 6-3
Four-Wheel-Drive . . . . . . . . . . . . . 5-26
Front Fog Lamp . . . . . . . . . . . . . . 5-29
High-Beam On . . . . . . . . . . . . . . . . 5-29
High/Low Beam Changer . . . . . . 6-3
Low Fuel Warning . . . . . . . . . . . . 5-28
Safety Belt Reminders . . . . . . . . 5-17
Security . . . . . . . . . . . . . . . . . . . . . . 5-29
StabiliTrak
®OFF . . . . . . . . . . . . . 5-27
Tire Pressure . . . . . . . . . . . . . . . . . 5-27
Tow/Haul Mode . . . . . . . . . . . . . . . 5-26
Traction Control System (TCS)/StabiliTrak
®. . . . . . . . . . 5-27
Locking Rear Axle . . . . . . . . . . . . . 9-58 Locks
Automatic Door . . . . . . . . . . . . . . . . 2-8
Delayed Locking . . . . . . . . . . . . . . . 2-8
Door . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
Lockout Protection . . . . . . . . . . . . . 2-9
Power Door . . . . . . . . . . . . . . . . . . . . 2-8
Safety . . . . . . . . . . . . . . . . . . . . . . . . . 2-9
Loss of Control . . . . . . . . . . . . . . . . . 9-5
Low Fuel Warning Light . . . . . . . . 5-28
Lower Anchors and Tethers for Children (LATCH
System) . . . . . . . . . . . . . . . . . . . . . . 3-47
Lumbar Adjustment . . . . . . . . . . . . . 3-4 Front Seats . . . . . . . . . . . . . . . . . . . . 3-4
M
MaintenanceRecords . . . . . . . . . . . . . . . . . . . . .11-16
Maintenance Schedule Recommended Fluidsand Lubricants . . . . . . . . . . . . .11-12
Transfer Case . . . . . . . . . . . . . . . . 9-40
Malfunction Indicator Lamp . . . . 5-22
Manual Mirrors . . . . . . . . . . . . . . . . 2-14 Manual Mode . . . . . . . . . . . . . . . . . . 9-38
Manual Windows . . . . . . . . . . . . . . 2-19
Memory Features . . . . . . . . . . . . . . 1-14
Memory Seats . . . . . . . . . . . . . . . . . . 3-7
Messages
Airbag System . . . . . . . . . . . . . . . . 5-45
Anti-theft Alarm System . . . . . . . 5-45
Battery Voltage andCharging . . . . . . . . . . . . . . . . . . . . 5-39
Brake System . . . . . . . . . . . . . . . . 5-40
Door Ajar . . . . . . . . . . . . . . . . . . . . . 5-40
Engine Cooling System . . . . . . . 5-41
Engine Oil . . . . . . . . . . . . . . . . . . . . 5-42
Engine Power . . . . . . . . . . . . . . . . 5-42
Fuel System . . . . . . . . . . . . . . . . . . 5-43
Key and Lock . . . . . . . . . . . . . . . . . 5-43
Lamp . . . . . . . . . . . . . . . . . . . . . . . . . 5-43
Object Detection System . . . . . 5-43
Ride Control System . . . . . . . . . . 5-44
Starting the Vehicle . . . . . . . . . . . 5-45
Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-45
Transmission . . . . . . . . . . . . . . . . . 5-46
Vehicle . . . . . . . . . . . . . . . . . . . . . . . 5-39
Vehicle Reminder . . . . . . . . . . . . . 5-47
Washer Fluid . . . . . . . . . . . . . . . . . 5-48