2010 GMC SIERRA service

Maintenance When Trailer Towing
The vehicle needs service more often when pulling a
trailer. See this manual's Maintenance Schedule or
Index for more information. Things that are especially
important in trailer operation are automatic transmission
fluid, engine oil, axle lubricant, belts, cooling system
and brake system. It is a good idea to inspect these
before and during the trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Trailer Wiring Harness
The vehicle is equipped with one of the following wiring
harnesses for towing a trailer or hauling a slide-in
camper.
Basic Trailer Wiring
All regular, extended cab and crew cab pickups have a
seven‐wire trailer towing harness.
For vehicles not equipped with heavy duty trailering, the
harness is secured to the vehicle's frame behind the
spare tire mount. The harness requires the installation
of a trailer connector, which is available through your
dealer/retailer.
If towing a light‐duty trailer with a standard four‐way
round pin connector, an adapter is available from your
dealer/retailer.
Heavy-DutyTrailer Wiring Harness
Package
For vehicles equipped with heavy duty trailering, the
harness is connected to a bracket on the hitch platform.
The seven-wire harness contains the following trailer
circuits:
.Yellow: Left Stop/Turn Signal
.Dark Green: Right Stop/Turn Signal
.Brown: Taillamps
.White: Ground
.Light Green: Back-up Lamps
.Red: Battery Feed*
.Dark Blue: Trailer Brake*
5-74

*The fuses for these two circuits are installed in the
underhood electrical center, but the wires are not
connected. They should be connected by your dealer/
retailer or a qualified service center. The fuse and wire
for the ITBC is factory installed and connected if the
vehicle is equipped with an ITBC. The fuse for the
battery feed is not required if the vehicle has an
auxiliary battery. If the vehicle does not have an
auxiliary battery, have your dealer/retailer or authorized
service center install the required fuse.
If charging a remote (non-vehicle) battery, press the
Tow/Haul mode button, if equipped, located at the end
of the shift lever. This will boost the vehicle system
voltage and properly charge the battery. If the trailer is
too light for Tow/Haul mode, or the vehicle is not
equipped with Tow/Haul, turn on the headlamps as a
second way to boost the vehicle system and charge
the battery.Camper/Fifth-Wheel Trailer Wiring Package
The seven-wire camper harness is located under the
front edge of the pickup box on the drivers side of the
vehicle, attached to the frame bracket. A connector
must be added to the wiring harness which connects to
the camper.
The harness contains the following camper/trailer
circuits:
.Yellow: Left Stop/Turn Signal
.Dark Green: Right Stop/Turn Signal
.Brown: Taillamps
.White: Ground
.Light Green: Back-up Lamps
.Red: Battery Feed
.Dark Blue: Trailer Brake
5-75

If the vehicle is equipped with the“Heavy-Duty
Trailering” option, please refer to “Heavy-Duty Trailer
Wiring Package” earlier in this section.
When the camper-wiring harness is ordered without the
heavy-duty trailering package, an eight-wire harness
with a seven-pin connector is located at the rear of the
vehicle and is tied to the vehicle's frame.
Electric Brake Control Wiring
Provisions
These wiring provisions are included with the vehicle as
part of the trailer wiring package. These provisions are
for an electric brake controller. The instrument panel
contains blunt cut wires behind the steering column for
the trailer brake controller. The harness contains the
following wires:
.Dark Blue: Brake Signal to Trailer Connector
.Red/Black: Battery
.Light Blue/White: Brake Switch
.White: Ground
It should be installed by your dealer/retailer or a
qualified service center.
If the vehicle is equipped with an ITBC, the blunt cuts
exist, but are not connected further in the harness. If an
aftermarket trailer brake controller is installed, the ITBC
must be disconnected. Do not power both ITBC and
aftermarket controllers to control the trailer brakes at the
same time.
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Section 6 Service and Appearance Care
Service. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4
Accessories and Modifications . . . . . . . . . . . . . . . . . . 6-4
California Proposition 65 Warning . . . . . . . . . . . . . . . 6-5
California Perchlorate Materials Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5
Doing Your Own Service Work . . . . . . . . . . . . . . . . . . 6-5
Adding Equipment to the Outside of the Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Gasoline Octane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
Gasoline Specifications . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
California Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8
Additives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8
Fuel E85 (85% Ethanol) . . . . . . . . . . . . . . . . . . . . . . . . . 6-9
Fuels in Foreign Countries . . . . . . . . . . . . . . . . . . . . . 6-11
Filling the Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-11
Filling a Portable Fuel Container . . . . . . . . . . . . . . . 6-13 Checking Things Under the Hood
. . . . . . . . . . . . . . .6-14
Hood Release . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-15
Engine Compartment Overview . . . . . . . . . . . . . . . . 6-16
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-18
Engine Oil Life System . . . . . . . . . . . . . . . . . . . . . . . . 6-20
Engine Air Cleaner/Filter . . . . . . . . . . . . . . . . . . . . . . . 6-21
Automatic Transmission Fluid (4-Speed Transmission) . . . . . . . . . . . . . . . . . . . . . 6-23
Automatic Transmission Fluid (6-Speed Transmission) . . . . . . . . . . . . . . . . . . . . . 6-26
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-30
Engine Coolant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-31
Engine Overheating . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-34
Overheated Engine Protection Operating Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-36
Engine Fan Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-37
Power Steering Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 6-37
Windshield Washer Fluid . . . . . . . . . . . . . . . . . . . . . . 6-38
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-39
Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-43
Jump Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-44
6-1

Section 6 Service and Appearance Care
Rear Axle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-48
Four-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-50
Front Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-52
Noise Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-53
Tampering with Noise Control
System Prohibited . . . . . . . . . . . . . . . . . . . . . . . . . . 6-53
Headlamp Aiming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-54
Bulb Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-57
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-57
Headlamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-57
Center High-Mounted Stoplamp (CHMSL) and Cargo Lamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-58
Pickup Box Identification and Fender Marker Lamps . . . . . . . . . . . . . . . . . . 6-59
Taillamps, Turn Signal, Stoplamps and Back-up Lamps . . . . . . . . . . . . . . . . . . . . . . . . 6-60
License Plate Lamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-62
Replacement Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-62
Windshield Wiper Blade Replacement . . . . . . . . . . .6-63Tires
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-64
Tire Sidewall Labeling . . . . . . . . . . . . . . . . . . . . . . . . . 6-65
Tire Terminology and Definitions . . . . . . . . . . . . . . . 6-70
Inflation - Tire Pressure . . . . . . . . . . . . . . . . . . . . . . . . 6-72
High-Speed Operation . . . . . . . . . . . . . . . . . . . . . . . . . 6-74
Dual Tire Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-74
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . 6-75
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . 6-76
Tire Inspection and Rotation . . . . . . . . . . . . . . . . . . . 6-80
When It Is Time for New Tires . . . . . . . . . . . . . . . . . 6-82
Buying New Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-83
Different Size Tires and Wheels . . . . . . . . . . . . . . . 6-85
Uniform Tire Quality Grading . . . . . . . . . . . . . . . . . . . 6-85
Wheel Alignment and Tire Balance . . . . . . . . . . . . 6-87
Wheel Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-87
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-89
If a Tire Goes Flat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-89
Changing a Flat Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-90
Removing the Spare Tire and Tools . . . . . . . . . . . . 6-92
Removing the Flat Tire and Installing the Spare Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-97
Secondary Latch System . . . . . . . . . . . . . . . . . . . . . 6-103
Storing a Flat or Spare Tire and Tools . . . . . . . . 6-106
Spare Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-109
6-2

Section 6 Service and Appearance Care
Appearance Care. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-110
Interior Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-110
Fabric/Carpet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-111
Leather . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-112
Instrument Panel, Vinyl, and Other Plastic Surfaces . . . . . . . . . . . . . . . . 6-112
Care of Safety Belts . . . . . . . . . . . . . . . . . . . . . . . . . . 6-112
Weatherstrips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-113
Washing Your Vehicle . . . . . . . . . . . . . . . . . . . . . . . . 6-113
Cleaning Exterior Lamps/Lenses . . . . . . . . . . . . . 6-113
Finish Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-114
Windshield and Wiper Blades . . . . . . . . . . . . . . . . . 6-114
Aluminum or Chrome-Plated Wheels and Trim . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-115
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-116
Sheet Metal Damage . . . . . . . . . . . . . . . . . . . . . . . . . 6-116
Finish Damage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-116
Underbody Maintenance . . . . . . . . . . . . . . . . . . . . . . 6-116
Chemical Paint Spotting . . . . . . . . . . . . . . . . . . . . . . 6-116 Vehicle Identification
. . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-117
Vehicle Identification Number (VIN) . . . . . . . . . . . 6-117
Service Parts Identification Label . . . . . . . . . . . . . 6-117
Electrical System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-117
Add-On Electrical Equipment . . . . . . . . . . . . . . . . . 6-117
Windshield Wiper Fuses . . . . . . . . . . . . . . . . . . . . . . 6-118
Power Windows and Other Power Options . . . 6-118
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . . 6-118
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . 6-119
Center Instrument Panel Fuse Block . . . . . . . . . 6-121
Underhood Fuse Block . . . . . . . . . . . . . . . . . . . . . . . 6-122
Capacities and Specifications . . . . . . . . . . . . . . . . . .6-126
6-3

Service
For service and parts needs, visit your dealer/retailer.
You will receive genuine GM parts and GM-trained and
supported service people.
Genuine GM parts have one of these marks:
Accessories and Modifications
When non‐dealer/non‐retailer accessories are added to
the vehicle, they can affect vehicle performance and
safety, including such things as airbags, braking,
stability, ride and handling, emissions systems,
aerodynamics, durability, and electronic systems like
antilock brakes, traction control, and stability control.
Some of these accessories could even cause
malfunction or damage not covered by the
vehicle warranty.
Damage to vehicle components resulting from the
installation or use of non‐GM certified parts, including
control module modifications, is not covered under the
terms of the vehicle warranty and may affect remaining
warranty coverage for affected parts.
GM Accessories are designed to complement and
function with other systems on the vehicle. Your
GM dealer/retailer can accessorize the vehicle using
genuine GM Accessories. When you go to your
GM dealer/retailer and ask for GM Accessories, you
will know that GM-trained and supported service
technicians will perform the work using genuine
GM Accessories.
Also, seeAdding Equipment to Your Airbag-Equipped
Vehicle on page 2‑91.
6-4

California Proposition 65 Warning
Most motor vehicles, including this one, contain
and/or emit chemicals known to the State of California
to cause cancer and birth defects or other reproductive
harm. Engine exhaust, many parts and systems, many
fluids, and some component wear by-products contain
and/or emit these chemicals.
California Perchlorate Materials
Requirements
Certain types of automotive applications, such as airbag
initiators, seat belt pretensioners, and lithium batteries
contained in remote keyless transmitters, may contain
perchlorate materials. Special handling may be
necessary. For additional information, see
www.dtsc.ca.gov/hazardouswaste/perchlorate.
Doing Your Own Service Work
If this vehicle is a Two‐mode Hybrid, see the Two‐mode
Hybrid manual for more information.
{WARNING:
You can be injured and the vehicle could be
damaged if you try to do service work on a
vehicle without knowing enough about it.
.Be sure you have sufficient knowledge,
experience, the proper replacement parts, and
tools before attempting any vehicle
maintenance task.
.Be sure to use the proper nuts, bolts, and
other fasteners. English and metric fasteners
can be easily confused. If the wrong fasteners
are used, parts can later break or fall off. You
could be hurt.
If doing some of your own service work, use the proper
service manual. It tells you much more about how to
service the vehicle than this manual can. To order the
proper service manual, see Service Publications
Ordering Information on page 8‑16.
This vehicle has an airbag system. Before attempting
to do your own service work, see Servicing Your
Airbag-Equipped Vehicle on page 2‑91.
6-5