2006 GMC SIERRA air conditioning

Engine Fan Noise
If your vehicle is equipped with 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. 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 you
may hear an increase in fan noise. 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.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch partially
disengages.
If your vehicle is equipped with electric cooling fans,
you may hear the fans spinning at low speed during most
everyday driving. The fans may turn off if no cooling is
required. Under heavy vehicle loading, trailer towing,
and/or high outside temperatures, or if you are operating
your air conditioning system, the fans change to high
speed and you may hear an increase in fan noise.
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
SeeEngine Compartment
Overview on page 5-14for
reservoir location.
When to Check Power Steering Fluid
It is not necessary to regularly check power steering uid
unless you suspect there is a leak in the system or you
hear an unusual noise. A uid loss in this system could
indicate a problem. Have the system inspected and
repaired.
5-45

Tire Terminology and Denitions
Air Pressure:The amount of air inside the tire pressing
outward on each square inch of the tire. Air pressure
is expressed in pounds per square inch (psi) or
kilopascal (kPa).
Accessory Weight:This means the combined weight
of optional accessories. Some examples of optional
accessories are, automatic transmission, power steering,
power brakes, power windows, power seats, and air
conditioning.
Aspect Ratio:The relationship of a tire’s height to
its width.
Belt:A rubber coated layer of cords that is located
between the plies and the tread. Cords may be made
from steel or other reinforcing materials.
Bead:The tire bead contains steel wires wrapped by
steel cords that hold the tire onto the rim.
Bias Ply Tire:A pneumatic tire in which the plies are
laid at alternate angles less than 90 degrees to the
centerline of the tread.Cold Ination Pressure:The amount of air pressure in
a tire, measured in pounds per square inch (psi) or
kilopascals (kPa) before a tire has built up heat
from driving. SeeInation - Tire Pressure on page 5-79.
Curb Weight:This means the weight of a motor
vehicle with standard and optional equipment including
the maximum capacity of fuel, oil and coolant, but
without passengers and cargo.
DOT Markings:A code molded into the sidewall of a
tire signifying that the tire is in compliance with the
U.S. Department of Transportation (DOT) motor
vehicle safety standards. The DOT code includes the
Tire Identication Number (TIN), an alphanumeric
designator which can also identify the tire manufacturer,
production plant, brand and date of production.
GVWR:Gross Vehicle Weight Rating, seeLoading
Your Vehicle on page 4-48.
GAWR FRT:Gross Axle Weight Rating for the front
axle, seeLoading Your Vehicle on page 4-48.
GAWR RR:Gross Axle Weight Rating for the rear axle,
seeLoading Your Vehicle on page 4-48.
5-76

Fuses Usage
LR PARKLeft Rear Parking and
Sidemarker Lamps
PARK LP Parking Lamps Relay
STRTR Starter Relay
INTPARK Interior Lamps
STOP LP Stoplamps
TBC BATTTruck Body Controller Battery
Feed
SEO B2 Off-Road Lamps
4WS Not Used
AUX PWRAuxiliary Power Outlet —
Console
PCM 1 Powertrain Control Module
ETC/ECMElectronic Throttle Control,
Electronic Brake
Controller-Gasoline Engine,
Fan Clutch-Diesel Engines
IGN EInstrument Panel Cluster,
Air Conditioning Relay,
Turn Signal/Hazard Switch,
Starter RelayFuses Usage
RTD Ride Control
TRL B/U Backup Lamps Trailer Wiring
F/PMP Fuel Pump (Relay)
B/U LPBack-up Lamps, Automatic
Transmission Shift Lock
Control System
RR DEFOG Rear Window Defogger
HDLP-HI Headlamp High Beam Relay
PRIME Not Used
AIRBAGSupplemental Inatable
Restraint System
FRT PARKFront Parking Lamps,
Sidemarker Lamps
DRLDaytime Running Lamps
(Relay)
SEO IGN Rear Defog Relay
TBC IGN1 Truck Body Controller Ignition
HI HDLP-LT High Beam Headlamp-Left
LH HID Not Used
5-130

Fuses Usage
DRL Daytime Running Lamps
RVC Regulated Voltage Control
IPC/DICInstrument Panel
Cluster/Driver Information
Center
HVAC/ECAS Climate Control Controller
CIG LTR Cigarette Lighter
HI HDLP-RT High Beam Headlamp-Right
HDLP-LOW Headlamp Low Beam Relay
A/C COMPAir Conditioning Compressor
Relay
A/C COMP Air Conditioning Compressor
TCMB Transmission Control Module
RR WPR Not Used
RADIO Audio System
SEO B1Mid Bussed Electrical Center,
Rear Heated Seats,
Universal Home Remote
System
LO HDLP-LT Headlamp Low Beam-LeftFuses Usage
BTSIBrake Transmission Shift
Interlock System
CRNK Starting System
LO HDLP-RT Headlamp Low Beam-Right
FOG LP Fog Lamps Relay
FOG LP Fog Lamps
HORN Horn Relay
W/S WASHWindshield Washer Pump
Relay
W/S WASH Windshield Washer Pump
INFOOnStar
®/Rear Seat
Entertainment
RADIO AMP Radio Amplier
RH HID Not Used
HORN Horn
EAP Not Used
TREC Not Used
SBA Supplemental Brake Assist
5-131

Maintenance Footnotes
(Gasoline Engine)
This maintenance section applies to vehicles with a
gasoline engine. If your vehicle has a diesel engine,
see the maintenance schedule section in the
DURAMAX
®Diesel Engine Supplement.
†The U.S. Environmental Protection Agency or the
California Air Resources Board has determined that the
failure to perform this maintenance item will not nullify
the emission warranty or limit recall liability prior to the
completion of the vehicle’s useful life. We, however,
urge that all recommended maintenance services be
performed at the indicated intervals and the maintenance
be recorded.
#Lubricate the front suspension, ball joints, steering
linkage, transmission shift linkage, and parking brake
cable guides. Ball joints should not be lubricated unless
their temperature is 10°F (−12°C) or higher, or they could
be damaged. Vehicles used under severe commercial
operating conditions require lubrication on a regular basis
every 3,000 miles (5 000 km).
(a)Visually inspect brake lines and hoses for proper
hook-up, binding, leaks, cracks, chang, etc. Inspect
disc brake pads for wear and rotors for surface condition.
Inspect drum brake linings/shoes for wear or cracks.
Inspect other brake parts, including drums, wheel
cylinders, calipers, parking brake, etc.(b)Visually inspect front and rear suspension and
steering system for damaged, loose or missing parts,
signs of wear or lack of lubrication. Inspect power
steering lines and hoses for proper hook-up, binding,
leaks, cracks, chang, etc. Visually check constant
velocity joints, rubber boots, and axle seals for leaks.
(c)Visually inspect hoses and have them replaced if they
are cracked, swollen, or deteriorated. Inspect all pipes,
ttings and clamps; replace with genuine GM parts as
needed. To help ensure proper operation, a pressure test
of the cooling system and pressure cap and cleaning the
outside of the radiator and air conditioning condenser is
recommended at least once a year.
(d)Visually inspect wiper blades for wear or cracking.
Replace wiper blades that appear worn or damaged
or that streak or miss areas of the windshield.
(e)Make sure the safety belt reminder light and all your
belts, buckles, latch plates, retractors, and anchorages
are working properly. Look for any other loose or
damaged safety belt system parts. If you see anything
that might keep a safety belt system from doing its job,
have it repaired. Have any torn or frayed safety belts
replaced. Also look for any opened or broken airbag
coverings, and have them repaired or replaced. The
airbag system does not need regular maintenance.
6-9

A
Accessories and Modications............................ 5-4
Accessory Power Outlet(s)...............................3-20
Adding a Snow Plow or Similar Equipment.........4-54
Adding Equipment to Your Airbag-Equipped
Vehicle.......................................................1-86
Additives, Fuel................................................. 5-7
Add-On Electrical Equipment...........................5-123
Air Cleaner/Filter, Engine.................................5-25
Air Conditioning..............................3-21, 3-22, 3-25
Airbag
Off Light.....................................................3-35
Passenger Status Indicator...........................3-37
Readiness Light..........................................3-35
Airbag Sensing and Diagnostic Module (SDM)...... 7-9
Airbag System................................................1-70
Adding Equipment to Your Airbag-Equipped
Vehicle...................................................1-86
Airbag Off Switch........................................1-78
How Does an Airbag Restrain?......................1-76
Passenger Sensing System...........................1-81
Servicing Your Airbag-Equipped Vehicle..........1-86
What Makes an Airbag Inate?......................1-76
What Will You See After an Airbag Inates?....1-76
When Should an Airbag Inate?....................1-74
Where Are the Airbags?...............................1-72
AM-FM Radio.................................................3-72
Antenna, Fixed Mast......................................3-132
Antenna, XM™ Satellite Radio Antenna System . . . 3-133Anti-Lock Brake System (ABS)........................... 4-6
Anti-Lock Brake, System Warning Light..............3-42
Appearance Care
Aluminum or Chrome-Plated Wheels.............5-118
Care of Safety Belts...................................5-116
Chemical Paint Spotting..............................5-120
Cleaning Exterior Lamps/Lenses..................5-117
Cleaning the Inside of Your Vehicle..............5-113
Fabric/Carpet............................................5-114
Finish Care...............................................5-117
Finish Damage..........................................5-120
Instrument Panel, Vinyl, and Other
Plastic Surfaces.....................................5-115
Leather....................................................5-115
Sheet Metal Damage..................................5-119
Tires........................................................5-119
Underbody Maintenance.............................5-120
Vehicle Care/Appearance Materials...............5-121
Washing Your Vehicle.................................5-116
Weatherstrips............................................5-116
Windshield and Wiper Blades......................5-118
Ashtray(s)......................................................3-20
Audio System(s).............................................3-70
AM-FM Radio.............................................3-72
Audio Steering Wheel Controls....................3-129
Care of Your Cassette Tape Player...............3-131
Care of Your CD and DVD Player................3-132
Care of Your CDs and DVDs.......................3-132
Chime Level Adjustment.............................3-133
Fixed Mast Antenna...................................3-132
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